Stepping Up to Combat Urban Diabetes
Providing financial incentives to walk at least 10,000 steps per day led to increased exercise and moderate physical and mental health improvements among diabetics and prediabetics in India, with "threshold" contracts being especially effective for diabetics who are more impatient.
Incentives for walking were highly effective at inducing exercise. Providing INR20 (US$0.33) per day of meeting the 10,000 daily step target increased compliance by 20 percentage points (a 67 percent increase), raising the average number of steps per day even during the three months after the intervention ended.
Incentives led to moderate physical and mental health improvements. The incentives program improved health outcomes by 0.05 standard deviations, as measured through a health risk index comprising measures such as body mass index (BMI) and random blood sugar. Mental health improved by 0.1 standard deviations.
Incentives designed with minimum thresholds of days walked for receiving rewards increased walking more among impatient individuals. Because impatient individuals discount the effort of future walking, thresholds that effectively ‘bundle’ rewards for walking now with walking in the future were particularly effective for them. For patient individuals, threshold payments decreased compliance, highlighting the importance of tailoring incentive contracts to the patience of the individual.
Increasing payment frequency had no impact on the number of steps walked. Daily, weekly, and monthly incentive payments were equally effective at increasing walking, indicating limited impatience over financial payments.
Threshold contracts were the most cost-effective variant of the incentive program.