A controlled time-series trial of clinical reminders: Using computerized firm systems to make quality improvement research a routine part of mainstream practice

Objective. To explore the feasibility of conducting unobtrusive interventio nal research in community practice settings by integrating firm-system tech niques with time-series analysis of relational-repository data. Study Setti ng. A satellite teaching clinic divided into two similar, but geographicall y separated, primary care group practices called firms. One firm was select ed by chance to receive the study intervention. Forty-two providers and 2,6 55 patients participated. Study Design. A nonrandomized controlled trial of computer-generated preven tive reminders. Net effects were determined by quantitatively combining pop ulation-level data from parallel experimental and control interrupted time series extending over two-month baseline and intervention periods. Data Collection. Mean rates at which mammography, colorectal cancer screeni ng, and cholesterol testing were performed on patients due to receive each maneuver at clinic visits were the trial's outcome measures. Principal Findings. Mammography performance increased on the experimental f irm by 154 percent (0.24 versus 0.61, P = .03). No effect on fecal occult b lood testing was observed. Cholesterol ordering decreased on both the exper imental (0.18 versus 0.11, p = .02) and control firms (0.13 versus 0.07, P = .03) coincident with national guidelines retreating from recommending scr eening for young adults. A traditional uncontrolled interrupted time-series design would have incorrectly attributed the experimental firm decrease to the introduction of reminders. The combined analysis properly indicated th at no net prompting effect had occurred, as the difference between firms in cholesterol testing remained stochastically stable over time (0.05 versus 0.04, P = .75). A logistic-regression analysis applied to individual-level data produced equivalent findings. The trial incurred no supplementary data collection costs. Conclusions. The apparent validity and practicability of our reminder imple mentation study should encourage others to develop computerized firm system s capable of conducting controlled time-series trials.