Validation of the Revised Individual Placement and Support Fidelity Scale (IPS-25)

Objective:

The individual placement and support (IPS) model of supported employment for people with severe mental illness is an evidence-based practice. The 15-item IPS Fidelity Scale (IPS-15) was developed to measure program fidelity and has been shown to have good psychometric properties, including predictive validity. On the basis of field experience and research updates, the authors developed an expanded and revised version of this scale, the IPS-25, also known as the Supported Employment Fidelity Scale. This study evaluated the psychometric properties of the IPS-25.

Methods:

In addition to data on the local unemployment rate and program longevity, the authors collected IPS-25 ratings and employment data for 79 sites in eight states participating in a learning collaborative devoted to implementing the IPS model. Descriptive data for items and the total scale and predictive validity were examined.

Results:

Internal consistency reliability for the IPS-25 was .88. Predictive validity, measured as the correlation between the IPS-25 and site-level employment rate, was .34. Eight of the IPS-25 items were significantly positively correlated with employment rate. Items related to the vocational generalist role, disclosure, follow-along support, and vocational unit were the most strongly correlated with employment. Program longevity was positively associated with employment, whereas the unemployment rate was not.

Conclusions:

The IPS-25 has promising psychometric properties, with greater precision and content coverage than the IPS-15. However, it has not demonstrated an advantage over the IPS-15 in predictive validity. Research directly comparing the two scales is needed. (Psychiatric Services 63:758–763, 2012; doi: 10.1176/appi.ps.201100476)