A RANDOMIZED CONTROLLED TRIAL TO MOTIVATE AND SUSTAIN PHYSICAL - PowerPoint PPT Presentation

A RANDOMIZED CONTROLLED TRIAL TO MOTIVATE AND SUSTAIN PHYSICAL ACTIVITY AMONG TAXI DRIVERS USING FINANCIAL INCENTIVES – TAKSI STUDY D R E R I C A F I N K E L S T E I N ( P I ) Professor, Health Services & Systems Research, Duke-NUS Singapore • D R H O T E C K H U A ( C O - I ) Deputy President and Tan Chin Tuan Centennial Professor, National University of • Singapore Professor, Haas School of Business, University of California, Berkeley • D R U R I G N E E Z Y ( C O - I ) Professor, Rady School of Management, University of California, San Diego • D R M A R C E L B I L G E R ( C O - I ) Assistant Professor, Health Services & Systems Research, Duke-NUS Singapore • Funding: NUS Institute to Improve Health in Asia (NIHA) June 25 th , 2015

Outline q Background q Study design q Testable hypotheses q Preliminary Results q Discussion

A sedentary population group q There are above 28,000 registered taxis in Singapore q Taxi drivers are an especially sedentary group due to their long shifts and working conditions q Taxi drivers are also unlikely to Source: www.taxi-photos.com engage in structured physical activity programs due to their unusual shifts. q Lack of physical activity puts taxi drivers at risk to a wide range of Non-Communicable Diseases (e.g. Pate et al., 1995)

Financial incentives to promote physical activity q Neo-classical economics predicts that q financial incentives can motivate drivers to increase their physical activity q cash incentives would work best as cash is assumed to be fully fungible q Research in behavioral economics showed that q individuals partition their budget according to expense types, which is a form of mental accounting (Thaler, 1980) q individuals prefer avoiding losses to acquiring gains (Kahneman and Tversky, 1984) Our approach is to incentivize drivers with taxi rental credits to capitalize on both mental accounting and loss aversion

Study design q The TAKSI study measures the effect of Cash and Taxi Rental incentives on physical activity and health among taxi drivers aged 50 to 75 q 316 eligible taxi drivers were randomized into one of two equisized parallel study arms: Arm 1 : Drivers receive Cash incentives if they achieve activity goals Arm 2 : Drivers receive Taxi Rental credits if they achieve activity goals q The only difference between the two arms is how the reward is framed ü the incentive amounts are the same in both groups. q In both arms, the incentive is reinforced by means of study messaging and monthly reports on physical activity and target attainment

Study design, goals and timeline q The program takes 8 months to Intervention Post-intervention period period Baseline complete, including baseline, intervention (Months ¡1 ¡to ¡4) ¡ (Months ¡5 ¡to ¡7) ¡ (Month 0) and post-intervention period 28 days (per 28 days (per Timeline ¡ 21 days ¡ month) ¡ month) ¡ At least 7,000 q In the intervention period, drivers can earn steps in 20 or Step target ¡ incentives by meeting specified step targets more days (per month) ¡ None ¡ None ¡ – 7,000 or more steps daily in at least 20 out One day Taxi of 28 days in a month Financial rental credit Incentive ¡ (per month) ¡ § Incentives are removed after Month 4 None ¡ None ¡ • Daily steps activity • Daily driving data – mileage, earnings and log-on q All participants hours receive a Fitbit Zip™ Data • Biometrics – height , weight, resting heart rate wireless pedometer to Collected and blood pressure (at Months 0, 4 and 7) monitor daily step • Self-reported health and work productivity (at activity Months 0, 4 and 7) q Assessments are done at Months 0, 4 and 7 to collect info on biometrics and self-reported health status

Testable Hypotheses q Financial incentives increase physical activity and improve health outcomes H1: Drivers in both arms will have a higher number of steps at Month 4 compared to baseline q Rental Credit incentives are more effective than cash incentives H2: Month 4 Improvements will be greater in the Taxi Rental arm compared to the Cash arm Financial incentives will lead to habit formation even when they are withdrawn and this effect will be larger in the Taxi Rental arm Same comparisons as above between Month 7 and baseline, that is 3 months after financial incentives have been discontinued

Study participants (baseline) q 157 drivers are assigned to By Incentive Arm ¡ Rental arm while 159 drivers are Rental arm Cash arm Baseline characteristics ¡ All (N=316) ¡ (N=157) ¡ (N=159) ¡ in the Cash arm Average age ¡ 58.6 (sd=4.8 ) ¡ 58.2 (sd=4.6) ¡ 58.9 (sd=4.9) ¡ Gender ¡ ¡ ¡ ¡ Female ¡ 1.91% ¡ 1.92% ¡ 1.90% ¡ q The drivers are 59 years old Male ¡ 98.09% ¡ 98.08% ¡ 98.10% ¡ on average Ethnicity ¡ ¡ ¡ ¡ Chinese ¡ 88.5% ¡ 87.8% ¡ 89.2% ¡ Malay ¡ 4.5% ¡ 5.8% ¡ 3.2% ¡ Indian ¡ 6.4% ¡ 5.8% ¡ 7.0% ¡ q Most of the drivers are Others ¡ 0.6% ¡ 0.6% ¡ 0.6% ¡ Chinese (89%), married (94%), Marital status ¡ ¡ ¡ ¡ Married ¡ 93.6% ¡ 95.5% ¡ 91.8% ¡ males (98%) with at least Widowed ¡ 0.6% ¡ 0.0% ¡ 1.3% ¡ secondary education (87%) Divorced ¡ 3.5% ¡ 2.6% ¡ 4.4% ¡ Never married ¡ 2.2% ¡ 1.9% ¡ 2.5% ¡ Highest educational attainment ¡ ¡ ¡ ¡ Primary or lower ¡ 13.4% ¡ 14.1% ¡ 12.7% ¡ Secondary ¡ 76.8% ¡ 75.6% ¡ 77.9% ¡ Diploma or University Degree ¡ 9.9% ¡ 10.3% ¡ 9.5% ¡

Study participants (baseline) By Incentive Arm ¡ q Almost half of the drivers have monthly household income below Rental arm Cash arm Baseline characteristics ¡ All (N=316) ¡ (N=157) ¡ (N=159) ¡ $2,000 Household monthly income ¡ ¡ ¡ ¡ Below 2,000 ¡ 47.2% ¡ 49.0% ¡ 45.4% ¡ 2,000-2,999 ¡ 21.5% ¡ 21.8% ¡ 21.3% ¡ 3,000-3,999 ¡ 11.5% ¡ 10.2% ¡ 12.8% ¡ q Majority of the drivers (40%) 4,000 and over ¡ 19.8% ¡ 19.1% ¡ 20.6% ¡ are inactive or do little activity Usual pattern of daily physical ¡ ¡ ¡ activities ¡ than usual daily activities Inactive or little activity than usual 39.0% ¡ 39.0% ¡ 39.1% ¡ daily activities ¡ Regularly ( ≥ 5 days per week) q A large proportion of drivers 16.1% ¡ 16.9% ¡ 15.2% ¡ participate in low exertion level physical activities ¡ are overweight (44%) and obese Participate in aerobic exercises for 15.1% ¡ 16.9% ¡ 13.3% ¡ 20 to 60 minutes per week ¡ (33%) Participate in aerobic exercises for 16.7% ¡ 16.9% ¡ 16.6% ¡ 1 to 3 hours per week ¡ Participate in aerobic exercises for q 28% of the drivers are 13.1% ¡ 10.4% ¡ 15.9% ¡ over 3 hours per week ¡ hypertensive Hypertensive ¡ 28.8% ¡ 28.3% ¡ 29.3% ¡ BMI category ¡ ¡ ¡ ¡ Normal ¡ 23.4% ¡ 22.2% ¡ 22.4% ¡ Overweight ¡ 44.1% ¡ 44.0% ¡ 46.1% ¡ Obese ¡ 32.5% ¡ 33.9% ¡ 31.6% ¡

Effects on daily step activity – Intervention period at Month 4 9000 1535.39 2283.39 8000 q Drivers in both arms increased their 7000 6000 daily step activity 5000 6907.69 § Rental arm walks more than baseline 4000 6281.74 3000 by 2,283 steps 2000 § Cash arm walks more than baseline 1000 by 1,535 steps 0 Rental arm Cash arm Average steps at baseline Average increment at intervention period q The increase in daily steps is larger in Rental arm Intervention Average steps (per day) ¡ Baseline (N=316) ¡ Period (N=316) ¡ § Incremental difference: Rental arm ¡ 6281.7 ¡ 8565.1 ¡ 2,283 (Rental) –1,535 (Cash) = 748 steps (185.7) ¡ (180.5) ¡ Cash arm ¡ 6907.7 ¡ 8443.1 ¡ (238.4) ¡ (170.5) ¡ First diff - Rental arm ¡ Framing of the incentives as rental ¡ 2283.4*** ¡ (164.3) ¡ credit is more effective than cash First diff - Cash arm ¡ 1535.4*** ¡ (152.0) ¡ Diff-in-diff ¡ 748.0*** ¡ ¡ (223.78) ¡ * p<0.10, ** p<0.05, *** p<0.01 ¡ Standard errors in parentheses ¡

Effects on daily step activity – Post-intervention period at Month 7 9000 1169.78 8000 1994.49 q Drivers in both arms are walking less 7000 6000 without the incentive but are still more 5000 6907.69 active than baseline – habit formation 4000 6281.74 3000 § Rental arm walks more than baseline 2000 by 1,994 steps 1000 0 § Cash arm walks more than baseline Rental arm Cash arm by 1,169 steps Average steps at baseline Average increment at intervention period q The increment is bigger in Rental arm Post-­‑interven4on ¡ Average steps (per day) ¡ Baseline (N=316) ¡ Period ¡(N=297) ¡ § Incremental difference: Rental arm ¡ 6281.74 ¡ 8276.23 ¡ 1,994 (Rental) –1,169 (Cash) = 825 steps (185.71) ¡ (236.35) ¡ Cash arm ¡ 6907.69 ¡ 8077.48 ¡ (238.37) ¡ (173.30) ¡ First diff – Rental arm ¡ Financial incentives create habit ¡ 1994.49*** ¡ (223.77) ¡ formation and the effect is stronger by First diff – Cash arm ¡ 1169.78*** ¡ framing it as rental credit (181.99) ¡ Diff-in-diff ¡ 824.71*** ¡ ¡ (288.43) ¡ Note: Estimates are still preliminary as data collection is still on going. * p<0.10, ** p<0.05, *** p<0.01 ¡ Final data collection is in July. Standard errors in parentheses ¡