0
Get Alert
Please Wait... Processing your request... Please Wait.
You must sign in to sign-up for alerts.

Please confirm that your email address is correct, so you can successfully receive this alert.

1
Article   |    
The Impact of Cost Sharing on Antidepressant Use Among Older Adults in British Columbia
Philip S. Wang, M.D., Dr.P.H.; Amanda R. Patrick, M.S.; Colin R. Dormuth, Sc.D.; Jerry Avorn, M.D.; Malcolm Maclure, Sc.D.; Claire F. Canning, M.A.; Sebastian Schneeweiss, M.D.
Psychiatric Services 2008; doi: 10.1176/appi.ps.59.4.377

Objective: Antidepressant therapies are underused among older adults and could be further curtailed by patient cost-sharing requirements. The authors studied the effects of two sequential cost-sharing policies in a large, stable population of all British Columbia seniors: change from full prescription coverage to $10—$25 copayments (copay) in January 2002 and replacement with income-based deductibles and 25% coinsurance in May 2003. Methods: PharmaNet data were used to calculate monthly dispensing of antidepressants (in imipramine-equivalent milligrams) among all British Columbia residents age 65 and older beginning January 1997 through December 2005. Monthly rates of starting and stopping antidepressants were calculated. Population-level patterns over time were plotted, and the effects of implementing cost-sharing policies on antidepressant use, initiation, and stopping were examined in segmented linear regression models. Results: Implementation of the copay policy was not associated with significant changes in level of antidepressant dispensing or the rate of dispensing growth. Subsequent implementation of the income-based deductible policy also did not lead to a significant change in dispensing level but led to a significant (p=.02) decrease in the rate of growth of antidepressant dispensing. The copay policy was associated with a significant (p=.01) drop in the frequency of antidepressant initiation among persons with depression. Income-based deductibles reduced the rate of increase in antidepressant initiation over time. Implementation of the copay and income-based deductible policies did not have significant effects on stopping rates. Conclusions: Introducing new forms of medication cost sharing appears to have the potential to reduce some use and initiation of antidepressant therapy by seniors. The clinical consequences of such reduced use need to be clarified. (Psychiatric Services 59:377—383, 2008)

Abstract Teaser
Figures in this Article

Dr. Wang is affiliated with the National Institute of Mental Health, 6001 Executive Blvd., Rm. 7141, MSC 9629, Bethesda, MD 20892-9629 (e-mail: wangphi@mail.nih.gov). Ms. Patrick, Dr. Avorn, Ms. Canning, and Dr. Schneeweiss are with the Division of Pharmacoepidemiology, Brigham and Women's Hospital, Boston. Dr. Dormuth is with the Therapeutics Initiative, University of British Columbia, Vancouver. Dr. Maclure is with the School of Health Information Science, University of Victoria, Victoria, British Columbia. This research was presented in a poster session at the 22nd International Conference on Pharmacoepidemiology and Therapeutic Risk Management, Lisbon, Portugal, August 24—27, 2006.

Depression burdens nearly one in six persons over age 65 with substantial morbidity, mortality, and costs (1,2,3). Although treatment consists almost entirely of antidepressants (4,5), pharmacotherapy for depression among older populations can be problematic (6,7). Perhaps partly a result of high costs, many elderly persons with depression never begin appropriate antidepressant regimens, and of those who do, less than half fill prescriptions for 30 days or more (8,9,10,11,12,13).

Although the Medicare Modernization Act (MMA) in the United States improves seniors' access to antidepressants through Medicare Part D coverage, it may also lead to large expenditures for these medications (14). There are particular pressures to control such psychotropic costs, because the proportion of spending on prescription drugs is twice as high in mental health care as in general health care (15). Costs of psychotropic medications have increased 17% annually, far outpacing other mental health expenditures and spending increases on medications overall (15,16). Newer agents with potentially greater tolerability are widely available (16,17,18), making antidepressants among the most widely prescribed classes of medications in most health care systems (19,20).

Prescription benefit plans operating under Medicare Part D use many strategies to contain costs, including via copayments, coinsurance, income-based deductibles, and combinations of these (21). Copayments require a fixed amount to be paid for each prescription. Copayments also can be tiered, with the lowest tier for generics, requiring small copays, and higher tiers for brand names, requiring larger copays. Coinsurance requires payment of a proportion of the medication price. Coinsurance policies have been criticized as being unfair to sicker patients who require more medications (22). Therefore, most coinsurance policies have annual out-of-pocket ceilings; costs up to the ceiling are paid out of pocket, whereas costs above the ceiling are reimbursed. Ceiling amount also can be linked to income in the prior year, under the presumption that patients with higher incomes can afford to pay more for medications. Such forms of cost sharing might reduce payers' expenditures by increasing patients' out-of-pocket contributions, thereby ensuring the fiscal viability of medication assistance programs for seniors. However, some analysts argue that coverage restrictions will adversely affect the elderly population's use of essential medications (23,24). For these reasons, it is critical to understand how medication cost sharing affects older patients, especially those who use antidepressants.

Aims of this study were to evaluate the impact of two sequential large-scale "natural experiments" in cost sharing on antidepressant use among seniors in British Columbia, Canada. In January 2002 the province-funded prescription benefit program introduced a copayment ("copay") policy requiring a $25 Canadian copay ($10 Canadian for low-income seniors). In May 2003 this copay policy was replaced by a second policy, which featured an income-based deductible, 25% coinsurance once a beneficiary's deductible was met, and full coverage once an out-of-pocket ceiling was met. The transition from one new policy to the next emulates the experience of many U.S. seniors who transitioned from private insurance programs requiring copays to Medicare's medication coverage system requiring deductibles and coinsurance. This natural experiment among all elderly British Columbia residents provided a unique opportunity to evaluate the impact of these two sequential cost-sharing interventions on antidepressant utilization, initiation, and discontinuation.

+

Data

Prescription records were obtained from the PharmaNet database, which contains records of all prescriptions dispensed at community pharmacies in British Columbia, regardless of payer, since 1996. Underreporting and misclassification are minimal (25). Prescription records were linked by encrypted personal health numbers to Ministry of Health administrative databases for physician services, hospitalizations, and deaths. These databases contain diagnostic codes and dates of service, admission, or death. The completeness and misclassification of diagnostic coding are probably similar to comparable databases (26,27).

+

Antidepressant utilization

Our primary analysis included all British Columbia residents age 65 and older and focused on patterns of antidepressant dispensing from January 1, 1997, to December 31, 2005. Because the cost-sharing policies could have affected the number of prescriptions filled and the strength of those prescriptions, we sought a dispensing metric that would be sensitive to both types of changes. For each medication, we converted the number of milligrams dispensed into the number of milligrams of imipramine that would be equivalent in strength (28) and tallied the number of imipramine-equivalent milligrams dispensed each month. Monthly dispensing was then divided by the British Columbia senior population during that month (29). Because bupropion is marketed for depression and smoking cessation and the indication cannot be determined with certainty from claims data, we excluded bupropion in our primary analysis but included it in a sensitivity analysis.

+

Antidepressant starting and stopping

To better understand dispensing patterns, we computed monthly rates of antidepressant starting and stopping. Starting an antidepressant was defined as filling a prescription and having no antidepressant fills in the previous six months. Numbers of new starts were tallied over the British Columbia senior population. In a second analysis, we restricted the study population to persons with a recorded depression diagnosis and no antidepressant use in the past six months. Persons counted toward the denominator of this cohort until they filled a prescription for an antidepressant or until six months had elapsed since their most recent depression diagnosis.

For our stopping analysis, we first identified persons as they initiated antidepressant therapy, defined as filling an antidepressant prescription without having filled one in the past year. Individuals were allowed to contribute multiple episodes of use to this analysis. We then created a patient coverage diary for each treatment period by stringing together consecutive prescriptions based on pharmacist-reported days' supply dispensed, calculated days' supply available from previous fills, and fill dates. Stopping was defined as failing to refill a prescription within 90 days of exhausting available supply, and the patient was assumed to have stopped on the date when his or her supply should have run out. Individuals were considered part of the cohort until death, emigration, discontinuation, or one year elapsed after initiation, whichever came first. We calculated monthly stopping rates as the number of persons stopping an antidepressant during the month divided by the number of persons in the cohort during that month.

+

Statistical analyses

Trends in antidepressant utilization, initiation, and discontinuation were plotted over time. Segmented linear regression was used to identify changes in slope or level at the time of the policy changes (30). Our multivariate linear regression models of aggregated monthly rates included a constant term, a linear time trend, a binary indicator for the period after the introduction of the copay policy, a linear trend for time since the copay policy, a binary indicator for the period after the introduction of the income-based deductible policy, and a linear trend for time since the income-based deductible policy. For selected models we additionally included indicator terms for December and January to model year-end stockpiling. In our main model, effects of the income-based deductible policy were estimated relative to trends during the copayment policy period. In a secondary analysis, we compared trends during the income-based deductible policy directly with trends during the baseline policy. The parameter estimates of this model estimated the cumulative effect of the two policies. A Durbin-Watson test was used to determine autocorrelation, and where appropriate, an autoregressive error process was specified. Statistical significance of policy effects was determined from two-sided t tests.

This study was approved by the institutional review boards at Brigham and Women's Hospital as well as the University of Victoria in British Columbia.

Table 1 shows baseline covariates for our population during 2001, which represented the full-coverage period immediately before the policy change and occurred midstudy. The average age of current antidepressant users was 76; 69% were women. A total of 64% of patients had received at least one mental health prescription in the prior year, 9% had had at least one mental health specialty visit, and less than 1% had been hospitalized for mental health reasons. The subset of patients who were new users of antidepressants during this period and had a depression diagnosis in the previous six months was similar to the full group but used fewer mental health medications and fewer medications overall.

From 1997 to 2001, antidepressant dispensing increased at a rate of 857 imipramine-equivalent milligrams per month per 1,000 seniors (95% confidence interval [CI]=792 to 922) (Figure 1). Observed and predicted values are shown in Figure 2, and model parameter estimates are reported in Table 2. The median daily dose of 45 mg of imipramine per day during this period equates to an additional 19 patient days' worth of antidepressant dispensed.

The implementation of the copayment policy in January 2002 was associated with a drop in dispensing by 1,910 mg per month (CI=-7,111 to 3,290; 42 patient-day decrease in days' supply per month), but the growth rate of dispensing increased by 375 mg per month after the policy change (CI=-109.7 to 860.2; change in slope=decrease of eight patient-days per month). The subsequent implementation of the income-based deductible policy resulted in a nonsignificant decrease in the dispensing level and a significant decrease in the rate of dispensing growth by 626 mg per 1,000 seniors per month (CI=-1,132.8 to -119.3; change in slope=decrease of 14 patient-days per month). When the income-based deductible period was compared directly with the baseline period, there was no change in dispensing level, but dispensing growth slowed by 283 imipramine-equivalent milligrams per month (CI=-466.3 to -99.6).

The use of selective serotonin reuptake inhibitors (SSRIs) increased substantially over the study period. SSRIs accounted for 42% of imipramine-equivalent milligrams dispensed in January 1997, with this proportion increasing to 63% by December 2005. Use of new and second-generation agents as a proportion of total use also increased, from 11% to 22%, whereas tertiary amine use as a proportion of total use fell from 37% to 15%. Within the SSRI class, citalopram market share increased rapidly from the medication's first use in April 1999 to December 2005, when it accounted for 50% of total SSRI use. [A list of antidepressants included in the evaluation is provided as an online supplement to this article at ps.psychiatryonline.org.]

Rates of antidepressant initiation are shown in Figure 2. Antidepressant initiation increased from 4.3 starts per 1,000 per month in January 1997 to 5.0 starts per 1,000 per month in December 2001. The implementation of the copay policy was associated with a significant .38 per 1,000 drop in initiation level but no change in the rate of increase over time (Table 2). Growth in initiation rates slowed minimally by .03 starts per month (CI=-.066 to .004) with the introduction of the income-based deductible and coinsurance policy. Relative to the baseline period, the initiation level was reduced by .3 starts per 1,000 seniors (CI=-.55 to -.06), and the growth in initiation rates slowed by -.028 per 1,000 seniors (CI=-.038 to -.018).

Among patients with a recorded depression diagnosis in the prior six months and no use of antidepressants during that period, the baseline frequency of antidepressant initiation was 315 starts per 1,000 seniors in January 1998, which increased by .8 starts per 1,000 seniors per month over time (CI=.64 to .97) (Table 2). [A figure showing the number initiating antidepressants per 1,000 seniors per month with a recorded depression diagnosis in the previous six months is provided in an online supplement to this article at ps.psychiatryonline.org.] The copay policy resulted in a significant drop of 12.3 starts per 1,000 seniors (CI=-21.9 to -2.7). The income-based deductible policy resulted in a significant trend toward decrease (-1.2 starts per 1,000 seniors per month, CI=-2.2 to -.3). A similar decreasing trend and no change in number of starts per 1,000 seniors with depression were observed when comparing the coinsurance period directly with the baseline period.

At baseline 13% of antidepressant users stopped their medication each month. Rates of stopping decreased by .03% per month over time (-.06% to -.01%) (Figure 3 and Table 2). The implementation of the copayment and income-based deductible policies did not have a significant effect on stopping rates at the population level.

In this study of the general population of seniors in British Columbia, we found that implementing a copay policy led to an observable drop in antidepressant initiation. Replacement with an income-based deductible plus coinsurance policy also was associated with a slowing of the rate at which antidepressant use had been increasing. Neither policy affected the rates of antidepressant discontinuation.

Prior studies of the impact of cost-sharing mechanisms on medication utilization are generally consistent with these findings. Most (22,31,32,33,34,35,36,37,38) but not all (39) studies of copayments have observed declines in drug prescriptions ranging from 5% to 10%, even with relatively modest copays. Doubling copayments has reduced antidepressant use by 25% (40). The RAND health insurance experiment found that medication use was reduced by 33% in plans with 95% cost sharing (roughly equivalent to the uncovered period before patients reach their deductible in our study) (37,38). Introduction of a 25% coinsurance and income-based deductible policy among seniors in Ontario was associated with a 9% reduction in use of essential medications (22).

Several potential mechanisms could explain how increased sharing of medication cost decreased antidepressant utilization and initiation. A majority of seniors spend $500 or more per month for their medications (41), and they may be particularly sensitive to high costs because of their diminished financial resources (42). Even elderly persons with prescription benefits may be unable to cover increased cost sharing because of their generally fixed incomes (37). High costs may particularly curtail antidepressant use because of the stigma associated with mental health treatments among seniors (10,43,44,45,46,47). Older patients also frequently take multiple regimens for comorbid conditions and may decide to limit their antidepressant use so that they can pay for their other medications (22).

These results should be interpreted with several potential limitations in mind. Because of the sequential implementation of the policy changes in British Columbia, it is difficult to estimate the effect of a direct change from full coverage to an income-based deductible policy. Although we have compared trends during the application of the income-based deductible policy with those during the application of the baseline policy, medication use patterns after the income-based deductible period may have been affected by the introduction of the copay policy. The other comparison we have reported—that of the effect of the income-based deductible policy compared with the copay policy—may underestimate the impact of a shift from full coverage to the income-based deductible system because some patients who would have experienced "sticker shock" after the income-based deductible policy went into effect may already have done so after the transition from the full-coverage policy to the copay policy. Furthermore, the impact of the income-based deductible policy may have been mitigated because 60% of patients had already met their deductibles when the policy was introduced in May 2003. Notably, we observed evidence in December 2003 of seniors stockpiling antidepressants, an indication of their concern about facing the full deductible in subsequent months. It may be that by 2004, when seniors faced the full deductible, they had nearly two-thirds of a year to cope with and adapt to the full income-based deductible policy.

Another limitation is the lack of a concurrent control group. Because the policy changes affected all seniors in British Columbia, with the exception of noncomparable populations (for example, seniors residing in nursing homes), no appropriate concurrent control group exists. The validity of an uncontrolled time trend analysis rests on the assumption that no sudden changes resulting from other interventions or changes in the population occurred at the same time as the interventions of interest. However, the suddenness of the changes observed in our analysis and their coincidence with the policy changes suggest that they are attributable to the policy changes.

Finally, cost sharing did not appear to affect some utilization outcomes (for example, discontinuation), and it remains unclear to what extent any reductions in antidepressant use that did occur resulted in clinically meaningful consequences. However, age-related pharmacokinetic and pharmacodynamic changes could make seniors particularly vulnerable to regimens used inappropriately to save costs, increasing their risks of morbidity, hospitalizations, emergency room visits, nursing home placements, or even death from causes such as suicide (7,48). In part because of these possibilities, the net economic savings to insurers from these cost-sharing plans might also be less than anticipated (49). Prior studies of cost-sharing policies have been mixed, with some (50,51) but not all (52,53,54,55,56,57,58,59) finding increases in health care utilization outcomes and diminished savings after implementation. One study of limiting reimbursement for specifically psychotropic medications found that it led to increases in other health care expenditures that exceeded savings on psychotropic medications by a factor of 17 (60). Without measures of the severity of depression or other indications for antidepressants, it is unclear whether any decreases in use observed here represent an increase in unmet needs. However, given the substantial underutilization of depression treatments by older adults (8,9,10,11,12,13), there are grounds to suspect that decreased use may have caused unmet need.

With the assumption that undertreatment of depression among elderly patients remains a significant public health problem, efforts to increase their utilization of treatments continue to be needed (8,9,10,12). Model programs have been developed and have already proven successful at overcoming barriers to care and improving clinical outcomes among elderly persons with depression (61). Our results suggest that successful implementation of such model programs may also require taking into account and potentially intervening on any reductions in antidepressant use caused by patient cost sharing. Second, it remains crucial to continue conducting comparative research on different cost-sharing mechanisms and examining their effects on utilization, health, and economic outcomes. In this way, evidence-based and fiscally sound prescription drug policies can be designed for extremely vulnerable older populations with mental disorders.

This work was supported by grant R01-MH-069772 from the National Institute of Mental Health, grant R01-AG-021950 from the National Institute on Aging, and grant 5-R01-HS-010881-07 from the Agency for Healthcare Research and Quality.

Dr. Schneeweiss has received research grants from Pfizer, Inc. The other authors report no competing interests.

Lebowitz BD, Pearson JL, Schneider LS, et al: Diagnosis and treatment of depression in late life: consensus statement update. JAMA 278:1186—1190, 1997
 
Bruce MP, Leaf P, Rozal G, et al: Psychiatry status and 9-year mortality data in the New Haven Epidemiologic Catchment Area Study. American Journal of Psychiatry 51: 716—721, 1994
 
Unützer J, Patrick DL, Simon G, et al: Depressive symptoms and cost of health services in HMO patients aged 65 years and older. JAMA 277:1618—1623, 1997
 
Blazer DG: The OARS Durham surveys: description and application, in Multidimensional Functional Assessment: The OARS Methodology: A Manual, 2nd ed. Durham, NC, Center for the Study of Aging and Human Development, 1978
 
Olfson M, Pincus HA: Outpatient and mental health care in nonhospital settings: distribution of patients across provider groups. American Journal of Psychiatry 153:1353—1356, 1996
 
Wang PS, Schneeweiss S, Brookhart MA, et al: Suboptimal antidepressant use in the elderly. Journal of Clinical Psychopharmacology 25:118—126, 2005
 
Avorn J, Wang PS: Prescribing psychotropic drugs for the elderly: epidemiologic and policy considerations, in Clinical Geriatric Psychopharmacology, 4th ed. Edited by Salzman C. New York, McGraw-Hill, 2004
 
Schneider LS: Pharmacologic considerations in the treatment of late-life depression. American Journal of Geriatric Psychiatry 4 (suppl):S51—S65, 1996
 
Caine E, Lyness JM, Conwell Y: Diagnosis of late-life depression: preliminary studies in primary care settings. American Journal of Geriatric Psychiatry 4:45—51, 1996
 
Gurland B, Cross P, Katz S: Epidemiologic perspectives on opportunities for treatment of depression. American Journal of Geriatric Psychiatry 4:7—14, 1996
 
Luber MP, Meyers BS, Williams-Russo PG, et al: Depression and service utilization in elderly primary care patients. American Journal of Geriatric Psychiatry 9:169—176, 2001
 
Blanchard MR, Waterreus A, Mann AH: The nature of depression among older people in inner London and the contact with primary care. British Journal of Psychiatry 164:396—402, 1994
 
Unützer J, Simon G, Belin TR, et al: Care for depression in HMO patients aged 65 and older. Journal of the American Geriatrics Society 48:871—878, 2000
 
Medicare Prescription Drug Benefit Fact Sheet. Menlo Park, Calif, Henry J Kaiser Family Foundation, 2007. Available at www.kff.org/medicare/upload/704407.pdf
 
Mark TL, Coffey RM, McKusick DR, et al: National Estimates of Expenditures for Mental Health Services and Substance Abuse Treatment, 1991—2001. SAMHSA pub no SMA 05-3999. Rockville, Md, Substance Abuse and Mental Health Services Administration, 2005
 
Pincus HA, Tanielian TL, Marcus SC, et al: Prescribing trends in psychotropic medications: primary care, psychiatry, and other medical specialties. JAMA 279:526—531, 1998
 
Evidence Report on Treatment of Depression—Newer Pharmacotherapies. AHCPR pub no 99-E0130. Washington, DC, Agency for Health Care Policy and Research, 1999
 
Lydiard RB, Brawman-Mintzer O, Ballenger JC: Recent developments in the psychopharmacology of anxiety disorders. Journal of Consulting and Clinical Psychology 64:660—668, 1996
 
Mamdani MM, Parikh SV, Austin PC, et al: Use of antidepressants among elderly subjects: trends and contributing factors. JAMA 157:360—367, 2000
 
Harvard Pilgrim (HMO) prescription drug costs. Boston Globe, March 18, 1998
 
Hoadley J, Hargrave E, Cubanski J, et al: An In-Depth Examination of Formularies and Other Features of Medicare Drug Plans. Menlo Park, Calif, Kaiser Family Foundation, Apr 2006. Available at www.kff.org/medicare/upload/7489.pdf
 
Tamblyn R, Laprise R, Hanley JA, et al: Adverse events associated with prescription drug cost-sharing among poor and elderly persons. JAMA 285:421—429, 2001
 
Hsu J, Price M, Huang J, et al: Unintended consequences of caps on Medicare drug benefits. New England Journal of Medicine 354:2349—2359, 2006
 
Roblin DW, Platt R, Goodman MJ, et al: Effect of increased cost-sharing on oral hypoglycemic use in five managed care organizations: how much is too much? Medical Care 43:951—959, 2005
 
Anderson GM, Kerluke KJ, Pulcins IR, et al: Trends and determinants of prescriptions drug expenditures in the elderly: data from the British Columbia Pharmacare Program. Inquiry 30:199—207, 1993
 
Wilchesky M, Tamblyn RM, Huang A: Validation of diagnostic codes within medical services claims. Journal of Clinical Epidemiology 57:131—141, 2004
 
Folwes JB, Lawthers AG, Weiner JP, et al: Agreement between physicians' office records and Medicare Part B claims data. Health Care Financing Review 16:189—199, 1995
 
Salzman C: Clinical Geriatric Psychopharmacology, 4th ed. Philadelphia, Lippincott Williams and Wilkins, 2005
 
Health Data Warehouse. Victoria, British Columbia, BC Ministry of Health Services. Available at admin.moh.hnet.bc.ca/hdw. Accessed Sept 17, 2004
 
Wagner AK, Soumerai SB, Zhang F, et al: Segmented regression analysis of interrupted time series studies in medication use research. Journal of Clinical Pharmacy and Therapeutics 27:299—309, 2002
 
Huskamp HA, Deverka PA, Epstein AM, et al: The effect of incentive-based formularies on prescription drug-utilization and spending. New England Journal of Medicine 349:2224—2232, 2003
 
Roemer MI, Hopkins CE, Carr L, et al: Copayments for ambulatory care: penny-wise and pound foolish. Medical Care 13:457—466, 1975
 
Soumerai SB, Avorn J, Ross-Degnan D, et al: Payment restrictions for prescription drugs in Medicaid: effects on therapy, cost, and equity. New England Journal of Medicine 317:550—556, 1987
 
Reeder CE, Nelson AA: The differential impact of copayment on drug use in a Medicaid population. Inquiry 22:396—403, 1985
 
Nelson AA, Reeder CE, Dickson WM: The effect of a Medicaid drug copayment program on the utilization and cost of prescription services. Medical Care 22:724—736, 1984
 
Harris BL, Stergachis A, Ried LD: The effect of drug co-payments on utilization and cost of pharmaceuticals in a HMO. Medical Care 28:907—917, 1990
 
Leibowitz A, Manning WG, Newhouse JP: The demand for prescription drugs as a function of cost-sharing. Social Science and Medicine 21:1063—1069, 1985
 
Lohr KN, Brook RH, Kamberg CJ et al: Use of medical care in the RAND Health Insurance Experiment: diagnosis- and service-specific analyses in a randomized controlled trial. Medical Care 24(suppl):S39—S50, 1986
 
Johnson RE, Goodman MJ, Hornbrook MC, et al: The impact of increasing patient prescription drug cost sharing on therapeutic classes of drugs received and on the health status of elderly HMO members. Health Services Research 31:103—122, 1997
 
Goldman DP, Joyce GF, Escarce JJ, et al: Pharmacy benefits and the use of drugs by the chronically ill. JAMA 291:2344—2350, 2004
 
Safran DG, Neuman P, Schoen C, et al: Prescription drug coverage and seniors: findings from a 2003 national survey. Health Affairs 19:W5—152—W5-166, 2005
 
Iglehart JK: Health Policy 2001: Medicare and prescription drugs. New England Journal of Medicine 344:1010—1015, 2001
 
Unützer J, Katon W, Russo J, et al: Patterns of care for depressed older adults in a large staff-model HMO. American Journal of Geriatric Psychiatry 7:235—243, 1999
 
Callahan CM: Quality improvement research on late life depression in primary care. Medical Care 39:772—784, 2001
 
NIH Consensus Development Panel on Depression in Late Life: Diagnosis and treatment of depression in late life. JAMA 268: 1018—1024, 1992
 
Cole MG, Yaffe MJ: Pathway to psychiatric care of the elderly with depression. International Journal of Geriatric Psychiatry 11:157—161, 1996
 
Swartz MS, Wagner HR, Swanson JW, et al: Administrative update: utilization of services: I. comparing use of public and private mental health services: the enduring barriers of race and age. Community Mental Health Journal 34:133—144, 1998
 
Soumerai SB, Ross-Degnan D, Avorn J, et al: Effects of Medicaid drug-payment limits on admission to hospitals and nursing homes. New England Journal of Medicine 325: 1072—1077, 1991
 
Johnson RE, Goodman MJ, Hornbrook MC, et al: The effect of increased prescription drug cost-sharing on medical care utilization and expenses of elderly health maintenance organization members. Medical Care 35: 1119—1131, 1997
 
Thomas M, Mann J, Williams S: The impact of reference pricing on clinical lipid control. New Zealand Medical Journal 111:292—294, 1998
 
Thomas M, Mann J: Increased thrombotic vascular events after change of statin. Lancet 352:1830—1831, 1998
 
Motheral B, Fairman KA: Effect of a three-tier prescription copay on pharmaceutical and other medical utilization. Medical Care 39:1293—1304, 2001
 
Grootendorst PV, Dolovich LR, O'Brien BJ, et al: Impact of reference-based pricing of nitrates on the use and costs of anti-anginal drugs. Canadian Medical Association Journal 165:1011—1019, 2001
 
Marshall JK, Grootendorst PV, O'Brien BJ, et al: Impact of reference-based pricing for histamine-2 receptor antagonists and restricted access for proton pump inhibitors in British Columbia. Canadian Medical Association Journal 166:1655—1662, 2002
 
Hazlet TK, Blough DK: Health services utilization with reference drug pricing of histamine(2) receptor antagonists in British Columbia elderly. Medical Care 40:640—649, 2002
 
Schneeweiss S, Walker AM, Glynn RJ, et al: Outcomes of reference pricing for angiotensin-converting enzyme inhibitors. New England Journal of Medicine 346:822—829, 2002
 
Schneeweiss S, Soumerai SB, Glynn RJ, et al: Impacts of reference pricing for ACE inhibitors on drug utilization. Canadian Medical Association Journal 166:737—748, 2002
 
Schneeweiss S, Soumerai SB, Maclure M, et al: Clinical and economic consequences of reference pricing for dihydropyridine calcium channel blockers. Clinical Pharmacology and Therapeutics 74:388—400, 2003
 
Schneeweiss S, Dormuth C, Grootendorst P, et al: Net health plan savings from reference drug pricing for angiotensin-converting enzyme inhibitors in elderly British Columbia residents. Medical Care 42:653—660, 2004
 
Soumerai SB, McLaughlin TJ, Ross-Degnan D, et al: Effects of limiting Medicaid drug-reimbursement benefits on the use of psychotropic agents and acute mental health services by patients with schizophrenia. New England Journal of Medicine 331:650—655, 1994
 
Unützer J, Katon W, Callahan C, et al: Collaborative care management of late-life depression in the primary care setting: a randomized controlled trial. JAMA 288:2836—2845, 2002
 
Table 1  Baseline population characteristics of seniors receiving full prescription coverage in British Columbia in 2001
Table 2  Model parameter estimates of antidepressant dispensing per 1,000 seniors per month in British Columbia during the move from full prescription coverage, to copay, to income-based deductible (IBD) policies between 1997 and 2005
 
Antidepressants dispensed per 1,000 seniors per month in British Columbia between January 1997 and July 2006
 
Number of seniors in British Columbia initiating antidepressant use per 1,000 seniors per month between July 1997 and July 2005
 
Proportion of depressed seniors in British Columbia who discontinued their antidepressant medications in each month between January 1998 and July 2005

Figure 1  Antidepressants dispensed per 1,000 seniors per month in British Columbia between January 1997 and July 2006

Figure 2  Number of seniors in British Columbia initiating antidepressant use per 1,000 seniors per month between July 1997 and July 2005

Figure 3  Proportion of depressed seniors in British Columbia who discontinued their antidepressant medications in each month between January 1998 and July 2005
Table 1  Baseline population characteristics of seniors receiving full prescription coverage in British Columbia in 2001
Table 2  Model parameter estimates of antidepressant dispensing per 1,000 seniors per month in British Columbia during the move from full prescription coverage, to copay, to income-based deductible (IBD) policies between 1997 and 2005
+

References

Lebowitz BD, Pearson JL, Schneider LS, et al: Diagnosis and treatment of depression in late life: consensus statement update. JAMA 278:1186—1190, 1997
 
Bruce MP, Leaf P, Rozal G, et al: Psychiatry status and 9-year mortality data in the New Haven Epidemiologic Catchment Area Study. American Journal of Psychiatry 51: 716—721, 1994
 
Unützer J, Patrick DL, Simon G, et al: Depressive symptoms and cost of health services in HMO patients aged 65 years and older. JAMA 277:1618—1623, 1997
 
Blazer DG: The OARS Durham surveys: description and application, in Multidimensional Functional Assessment: The OARS Methodology: A Manual, 2nd ed. Durham, NC, Center for the Study of Aging and Human Development, 1978
 
Olfson M, Pincus HA: Outpatient and mental health care in nonhospital settings: distribution of patients across provider groups. American Journal of Psychiatry 153:1353—1356, 1996
 
Wang PS, Schneeweiss S, Brookhart MA, et al: Suboptimal antidepressant use in the elderly. Journal of Clinical Psychopharmacology 25:118—126, 2005
 
Avorn J, Wang PS: Prescribing psychotropic drugs for the elderly: epidemiologic and policy considerations, in Clinical Geriatric Psychopharmacology, 4th ed. Edited by Salzman C. New York, McGraw-Hill, 2004
 
Schneider LS: Pharmacologic considerations in the treatment of late-life depression. American Journal of Geriatric Psychiatry 4 (suppl):S51—S65, 1996
 
Caine E, Lyness JM, Conwell Y: Diagnosis of late-life depression: preliminary studies in primary care settings. American Journal of Geriatric Psychiatry 4:45—51, 1996
 
Gurland B, Cross P, Katz S: Epidemiologic perspectives on opportunities for treatment of depression. American Journal of Geriatric Psychiatry 4:7—14, 1996
 
Luber MP, Meyers BS, Williams-Russo PG, et al: Depression and service utilization in elderly primary care patients. American Journal of Geriatric Psychiatry 9:169—176, 2001
 
Blanchard MR, Waterreus A, Mann AH: The nature of depression among older people in inner London and the contact with primary care. British Journal of Psychiatry 164:396—402, 1994
 
Unützer J, Simon G, Belin TR, et al: Care for depression in HMO patients aged 65 and older. Journal of the American Geriatrics Society 48:871—878, 2000
 
Medicare Prescription Drug Benefit Fact Sheet. Menlo Park, Calif, Henry J Kaiser Family Foundation, 2007. Available at www.kff.org/medicare/upload/704407.pdf
 
Mark TL, Coffey RM, McKusick DR, et al: National Estimates of Expenditures for Mental Health Services and Substance Abuse Treatment, 1991—2001. SAMHSA pub no SMA 05-3999. Rockville, Md, Substance Abuse and Mental Health Services Administration, 2005
 
Pincus HA, Tanielian TL, Marcus SC, et al: Prescribing trends in psychotropic medications: primary care, psychiatry, and other medical specialties. JAMA 279:526—531, 1998
 
Evidence Report on Treatment of Depression—Newer Pharmacotherapies. AHCPR pub no 99-E0130. Washington, DC, Agency for Health Care Policy and Research, 1999
 
Lydiard RB, Brawman-Mintzer O, Ballenger JC: Recent developments in the psychopharmacology of anxiety disorders. Journal of Consulting and Clinical Psychology 64:660—668, 1996
 
Mamdani MM, Parikh SV, Austin PC, et al: Use of antidepressants among elderly subjects: trends and contributing factors. JAMA 157:360—367, 2000
 
Harvard Pilgrim (HMO) prescription drug costs. Boston Globe, March 18, 1998
 
Hoadley J, Hargrave E, Cubanski J, et al: An In-Depth Examination of Formularies and Other Features of Medicare Drug Plans. Menlo Park, Calif, Kaiser Family Foundation, Apr 2006. Available at www.kff.org/medicare/upload/7489.pdf
 
Tamblyn R, Laprise R, Hanley JA, et al: Adverse events associated with prescription drug cost-sharing among poor and elderly persons. JAMA 285:421—429, 2001
 
Hsu J, Price M, Huang J, et al: Unintended consequences of caps on Medicare drug benefits. New England Journal of Medicine 354:2349—2359, 2006
 
Roblin DW, Platt R, Goodman MJ, et al: Effect of increased cost-sharing on oral hypoglycemic use in five managed care organizations: how much is too much? Medical Care 43:951—959, 2005
 
Anderson GM, Kerluke KJ, Pulcins IR, et al: Trends and determinants of prescriptions drug expenditures in the elderly: data from the British Columbia Pharmacare Program. Inquiry 30:199—207, 1993
 
Wilchesky M, Tamblyn RM, Huang A: Validation of diagnostic codes within medical services claims. Journal of Clinical Epidemiology 57:131—141, 2004
 
Folwes JB, Lawthers AG, Weiner JP, et al: Agreement between physicians' office records and Medicare Part B claims data. Health Care Financing Review 16:189—199, 1995
 
Salzman C: Clinical Geriatric Psychopharmacology, 4th ed. Philadelphia, Lippincott Williams and Wilkins, 2005
 
Health Data Warehouse. Victoria, British Columbia, BC Ministry of Health Services. Available at admin.moh.hnet.bc.ca/hdw. Accessed Sept 17, 2004
 
Wagner AK, Soumerai SB, Zhang F, et al: Segmented regression analysis of interrupted time series studies in medication use research. Journal of Clinical Pharmacy and Therapeutics 27:299—309, 2002
 
Huskamp HA, Deverka PA, Epstein AM, et al: The effect of incentive-based formularies on prescription drug-utilization and spending. New England Journal of Medicine 349:2224—2232, 2003
 
Roemer MI, Hopkins CE, Carr L, et al: Copayments for ambulatory care: penny-wise and pound foolish. Medical Care 13:457—466, 1975
 
Soumerai SB, Avorn J, Ross-Degnan D, et al: Payment restrictions for prescription drugs in Medicaid: effects on therapy, cost, and equity. New England Journal of Medicine 317:550—556, 1987
 
Reeder CE, Nelson AA: The differential impact of copayment on drug use in a Medicaid population. Inquiry 22:396—403, 1985
 
Nelson AA, Reeder CE, Dickson WM: The effect of a Medicaid drug copayment program on the utilization and cost of prescription services. Medical Care 22:724—736, 1984
 
Harris BL, Stergachis A, Ried LD: The effect of drug co-payments on utilization and cost of pharmaceuticals in a HMO. Medical Care 28:907—917, 1990
 
Leibowitz A, Manning WG, Newhouse JP: The demand for prescription drugs as a function of cost-sharing. Social Science and Medicine 21:1063—1069, 1985
 
Lohr KN, Brook RH, Kamberg CJ et al: Use of medical care in the RAND Health Insurance Experiment: diagnosis- and service-specific analyses in a randomized controlled trial. Medical Care 24(suppl):S39—S50, 1986
 
Johnson RE, Goodman MJ, Hornbrook MC, et al: The impact of increasing patient prescription drug cost sharing on therapeutic classes of drugs received and on the health status of elderly HMO members. Health Services Research 31:103—122, 1997
 
Goldman DP, Joyce GF, Escarce JJ, et al: Pharmacy benefits and the use of drugs by the chronically ill. JAMA 291:2344—2350, 2004
 
Safran DG, Neuman P, Schoen C, et al: Prescription drug coverage and seniors: findings from a 2003 national survey. Health Affairs 19:W5—152—W5-166, 2005
 
Iglehart JK: Health Policy 2001: Medicare and prescription drugs. New England Journal of Medicine 344:1010—1015, 2001
 
Unützer J, Katon W, Russo J, et al: Patterns of care for depressed older adults in a large staff-model HMO. American Journal of Geriatric Psychiatry 7:235—243, 1999
 
Callahan CM: Quality improvement research on late life depression in primary care. Medical Care 39:772—784, 2001
 
NIH Consensus Development Panel on Depression in Late Life: Diagnosis and treatment of depression in late life. JAMA 268: 1018—1024, 1992
 
Cole MG, Yaffe MJ: Pathway to psychiatric care of the elderly with depression. International Journal of Geriatric Psychiatry 11:157—161, 1996
 
Swartz MS, Wagner HR, Swanson JW, et al: Administrative update: utilization of services: I. comparing use of public and private mental health services: the enduring barriers of race and age. Community Mental Health Journal 34:133—144, 1998
 
Soumerai SB, Ross-Degnan D, Avorn J, et al: Effects of Medicaid drug-payment limits on admission to hospitals and nursing homes. New England Journal of Medicine 325: 1072—1077, 1991
 
Johnson RE, Goodman MJ, Hornbrook MC, et al: The effect of increased prescription drug cost-sharing on medical care utilization and expenses of elderly health maintenance organization members. Medical Care 35: 1119—1131, 1997
 
Thomas M, Mann J, Williams S: The impact of reference pricing on clinical lipid control. New Zealand Medical Journal 111:292—294, 1998
 
Thomas M, Mann J: Increased thrombotic vascular events after change of statin. Lancet 352:1830—1831, 1998
 
Motheral B, Fairman KA: Effect of a three-tier prescription copay on pharmaceutical and other medical utilization. Medical Care 39:1293—1304, 2001
 
Grootendorst PV, Dolovich LR, O'Brien BJ, et al: Impact of reference-based pricing of nitrates on the use and costs of anti-anginal drugs. Canadian Medical Association Journal 165:1011—1019, 2001
 
Marshall JK, Grootendorst PV, O'Brien BJ, et al: Impact of reference-based pricing for histamine-2 receptor antagonists and restricted access for proton pump inhibitors in British Columbia. Canadian Medical Association Journal 166:1655—1662, 2002
 
Hazlet TK, Blough DK: Health services utilization with reference drug pricing of histamine(2) receptor antagonists in British Columbia elderly. Medical Care 40:640—649, 2002
 
Schneeweiss S, Walker AM, Glynn RJ, et al: Outcomes of reference pricing for angiotensin-converting enzyme inhibitors. New England Journal of Medicine 346:822—829, 2002
 
Schneeweiss S, Soumerai SB, Glynn RJ, et al: Impacts of reference pricing for ACE inhibitors on drug utilization. Canadian Medical Association Journal 166:737—748, 2002
 
Schneeweiss S, Soumerai SB, Maclure M, et al: Clinical and economic consequences of reference pricing for dihydropyridine calcium channel blockers. Clinical Pharmacology and Therapeutics 74:388—400, 2003
 
Schneeweiss S, Dormuth C, Grootendorst P, et al: Net health plan savings from reference drug pricing for angiotensin-converting enzyme inhibitors in elderly British Columbia residents. Medical Care 42:653—660, 2004
 
Soumerai SB, McLaughlin TJ, Ross-Degnan D, et al: Effects of limiting Medicaid drug-reimbursement benefits on the use of psychotropic agents and acute mental health services by patients with schizophrenia. New England Journal of Medicine 331:650—655, 1994
 
Unützer J, Katon W, Callahan C, et al: Collaborative care management of late-life depression in the primary care setting: a randomized controlled trial. JAMA 288:2836—2845, 2002
 
+
+

CME Activity

There is currently no quiz available for this resource. Please click here to go to the CME page to find another.
Submit a Comments
Please read the other comments before you post yours. Contributors must reveal any conflict of interest.
Comments are moderated and will appear on the site at the discertion of APA editorial staff.

* = Required Field
(if multiple authors, separate names by comma)
Example: John Doe



Web of Science® Times Cited: 7

Related Content
Articles
Books
The American Psychiatric Publishing Textbook of Geriatric Psychiatry, 4th Edition > Chapter 33.  >
The American Psychiatric Publishing Textbook of Geriatric Psychiatry, 4th Edition > Chapter 29.  >
The American Psychiatric Publishing Textbook of Geriatric Psychiatry, 4th Edition > Chapter 15.  >
The American Psychiatric Publishing Textbook of Geriatric Psychiatry, 4th Edition > Chapter 16.  >
The American Psychiatric Publishing Textbook of Geriatric Psychiatry, 4th Edition > Chapter 26.  >
Topic Collections
Psychiatric News
APA Guidelines
PubMed Articles