A fidelity measure for integrated management of depression in primary care

Integrated models of primary care depression management improve outcomes. Subsequent dissemination efforts and their evaluation need a fidelity measure.

We sought to develop and validate a fidelity measure using data gathered during routine clinical application of the clinical model.

Longitudinal outcome data on depression severity were obtained from 224 subjects experiencing major depression or dysthymia and assigned to a 3-component model (3CM) intervention. Data on 10 essential 3CM process-of-care components were obtained from telephone logs maintained by care managers administering 3CM care. Stakeholders (n = 23), including researchers, health care administrators, and care managers, independently rated the importance of the 10 elements distributing 100 points among the elements. Mean ratings were used as weights to construct a fidelity score. Predictive validity was assessed using logistic regression for patient response and remission at 3 and 6 months.

3CM fidelity was high, with a mean of 74.1 at 3 months and 75.9 at 6 months. Given a large gap in the scores' distribution, subjects were classified into zero, low-, and high-fidelity groups. Logistic regressions adjusting for baseline depression found a distinct continuum. Patients that were provided high fidelity 3CM were significantly more likely to achieve treatment response and remission at 3 months. At 6 months, high-fidelity care was again significantly more likely to produce a response, but remission rate did not differ from patients provided low fidelity.

Most patients received a substantially implemented "3CM dose." Even within this high implementation, however, a higher fidelity score was associated with better outcomes. The easily applied measure is a promising tool for monitoring the quality of implementation of integrated care.