Optimal design features for surveying low-income populations.

Improving Medicaid program effectiveness for underserved populations is hampered by low survey response rates. This study determined how to maximize Medicaid consumer satisfaction survey response rates to the Consumer Assessment of Health Plans Study (CAHPS) survey. In a public immunization clinic, 8 focus groups and 15 extended interviews were used to assess consumer-preferred survey design features and incentives. To test hypotheses, we conducted the following trial. Out of 10,733 total participants in a Kansas Medicaid managed care plan, 3,685 eligible for CAHPS were unduplicated by household. After randomization of the 968 households with valid addresses to one of three groups, a controlled trial was conducted to assess response rates to CAHPS survey formats and incentives. Response rates were 35% for a standard mailing, 44% for a user-friendly low-literacy mailing, and 64% for a user-friendly low-literacy mailing with a $10 contingent incentive. Both experimental arms significantly improved response compared with the control; the response rate of the mailing group with the incentive was higher than the response rate of the group receiving that mailing without any incentive (p<0.0001). Using consumer-based preferences significantly increased response rates to this Medicaid satisfaction survey. Raising CAHPS response rates may increase validity of Medicaid consumer satisfaction information.