Generalizability in the family-to-family education program randomized waitlist-control trial.

OBJECTIVE Randomized controlled trials (RCTs) may have limited generalizability for the community when a high proportion of individuals refuse randomization or otherwise do not participate-a not uncommon phenomenon. A randomized waitlist-control trial of the Family-to-Family (FTF) education program, a 12-week course offered by the National Alliance on Mental Illness for family members of adults with mental illness, was previously reported. This study assessed whether the RCT-derived estimates of effectiveness of FTF were generalizable to individuals who participated in FTF but declined participation in the RCT. METHODS Propensity score matching was used to create five quintiles, each containing scores for individuals in FTF or waitlist conditions and for decliners; scores were matched on multiple baseline characteristics (N=442) within each quintile. Effectiveness estimates, with standard errors, were derived for the decliner population on the basis of effectiveness estimates derived from participants in the RCT; estimates were weighted to the baseline distribution of quintiles for the decliners. RESULTS For each outcome, estimates of the effect sizes observed in the RCT were very similar to the effect sizes observed for the decliner population; confidence intervals also had a high degree of overlap. CONCLUSIONS This study suggests that the benefits of FTF observed in the RCT are generalizable to the group of individuals who declined RCT participation, providing further evidence of FTF's effectiveness. Propensity score matching was a useful statistical tool for addressing selection bias resulting from high rates of nonconsent in randomized waitlist-control trials.

[1]  Peter M. Steiner,et al.  Estimating the causal effect of randomization versus treatment preference in a doubly randomized preference trial. , 2012, Psychological methods.

[2]  L. Brown.  Consumer-Run Mental Health: Framework for Recovery , 2011 .

[3]  L. Dixon,et al.  Outcomes of a randomized study of a peer-taught Family-to-Family Education Program for mental illness. , 2011, Psychiatric services.

[4]  S. Segal,et al.  Self-help and community mental health agency outcomes: a recovery-focused randomized controlled trial. , 2010, Psychiatric services.

[5]  Robert D Gibbons,et al.  Using Non-experimental Data to Estimate Treatment Effects. , 2009, Psychiatric annals.

[6]  Paul R Rosenbaum,et al.  Combining propensity score matching and group-based trajectory analysis in an observational study. , 2007, Psychological methods.

[7]  L. Dixon,et al.  Outcomes of the peer‐taught 12‐week family‐to‐family education program for severe mental illness , 2004, Acta psychiatrica Scandinavica.

[8]  M. Leese,et al.  The Experience of Caregiving Inventory: further evidence , 2000, Social Psychiatry and Psychiatric Epidemiology.

[9]  S. Marcus,et al.  Assessing non-consent bias with parallel randomized and nonrandomized clinical trials. , 1997, Journal of clinical epidemiology.

[10]  K. Sawin,et al.  Measures of Family Functioning for Research and Practice: Introduction , 1994, Scholarly Inquiry for Nursing Practice.

[11]  C. Carver,et al.  Assessing coping strategies: a theoretically based approach. , 1989, Journal of personality and social psychology.

[12]  D. Rubin,et al.  Reducing Bias in Observational Studies Using Subclassification on the Propensity Score , 1984 .

[13]  F. Taylor,et al.  Efficacy of tonsillectomy for recurrent throat infection in severely affected children. Results of parallel randomized and nonrandomized clinical trials. , 1984, The New England journal of medicine.

[14]  L. Derogatis,et al.  The Brief Symptom Inventory: an introductory report , 1983, Psychological Medicine.

[15]  J. Chemali,et al.  Summary and discussion of “ The central role of the propensity score in observational studies for causal effects , 2014 .

[16]  H. Herrman,et al.  Caring for relatives with serious mental illness: the development of the Experience of Caregiving Inventory , 2004, Social Psychiatry and Psychiatric Epidemiology.

[17]  P. Koren,et al.  Measuring empowerment in families whose children have emotional disabilities: A brief questionnaire. , 1992 .