Effectiveness of four interventions in improving community health workers' performance in western Kenya: a quasi-experimental difference-in-differences study using a longitudinal data.

There was no single intervention to improve all the aspects of CHWs' performance. The refresher training significantly improved their health knowledge, while financial incentive enhanced the level of their job satisfaction. The combinations of regular refresher training and other intervention(s) are the recommended as the effective interventions in improving and further sustaining CHWs' performance.