Responder analysis confirms results of a stroke transitional care trial but provides more interpretable results

Interpreting between-group differences in patient-reported outcome measures can be challenging. Responder analyses, which compare the proportions of patients who achieve a meaningful clinical change, represent a more interpretable approach. We conducted a secondary responder analysis of the Michigan Stroke Transitions Trial (MISTT).

The MISTT randomized 265 patients with stroke to three treatment groups: usual care [UC], social work case management [SWCM], or social work case management plus access to a patient-oriented website [SWCM + website]. Two Patient-Reported Outcomes Measurement and Information System (PROMIS) Global-10 subscales (representing physical and mental health) and 5 additional patient-reported outcomes were collected at baseline and 90-days. Responder analyses were conducted using modified Poisson and linear regression using published minimal important differences. Multiple imputation was used to address missing data.

For the PROMIS-10 global physical health subscale, responders were 80% more common in the SWCM + website group compared to the UC group (relative risk = 1.8, 95% confidence interval [CI]: 1.0, 3.1), with a number needed to treat of 7 (95% CI: 3, 112). No significant treatment effects were observed for the PROMIS-10 global mental health subscale.

Results of this responder analysis were largely consistent with the original trial analysis but have the advantage of presenting treatment effects using more clinically interpretable number needed to treat metrics.