Predicting nursing home adherence to a clinical trial intervention: lessons for the conduct of cluster randomized trials.

Abstract

To describe factors predictive of nursing home (NH) adherence to a clinical trial intervention. Post hoc analysis of a cluster randomized trial (CRT) evaluating a structured communication intervention to improve nurse-physician telephone communication in NHs. NH. All eligible licensed nursing staff in all participating NHs. Adherence was defined as active participation for at least 3months of the 12-month trial. NH characteristics hypothesized to affect trial outcomes (profit status, bed size, nursing staff time, NH quality, and leadership turnover) were measured a priori. The association between intervention adherence, NH characteristics and preintervention questionnaire response rate was examined. Of 13 intervention NHs, seven adhered to the intervention. Three factors differentiated adherent from nonadherent NHs: director of nursing turnover (nonadherent NHs 50% vs adherent NHs 0%, P=.03); Centers for Medicare and Medicaid Services (CMS) nurse staffing rating (range: 1-5) (nonadherent NHs mean 3.7±0.5 vs adherent NHs mean 4.3±0.5), P=.048); and questionnaire response rate (nonadherent NHs 15.6±10.0% vs adherent NHs 34.2±12.1%, P=.02). Profit status, bed size, and number of NH deficiencies on state surveys were not significantly associated with intervention adherence. CMS nurse staffing rating, leadership turnover, and questionnaire response rate are associated with adherence to a CRT intervention. Pretrial evaluation of NH staffing rating by CMS and of response to a questionnaire can help investigators improve trial efficiency by screening for NHs likely to adhere to a CRT intervention.