Effectiveness of a pay-it-forward intervention compared with user-paid vaccination to improve influenza vaccine uptake and community engagement among children and older adults in China: a quasi-experimental pragmatic trial.

Dan Wu, Chenqi Jin, Khaoula Bessame, Fanny Fong-Yi Tang, Jason J Ong, Zaisheng Wang, Yewei Xie, Mark Jit, Heidi J Larson, Tracey Chantler, Leesa Lin, Wenfeng Gong, Fan Yang, Fengshi Jing, Shufang Wei, Weibin Cheng, Yi Zhou, Nina Ren, Shuhao Qiu, Jianmin Bao, Liufen Wen, Qinlu Yang, Junzhang Tian, Weiming Tang, Joseph D Tucker

Journal: The Lancet. Infectious diseases 2022;22(10):1484-1492

PMID: 35868342

Free Full Text on Elsevier Science View on PubMed

Abstract

BACKGROUND

China has low seasonal influenza vaccination rates among priority populations. In this study, we aimed to evaluate a pay-it-forward strategy to increase influenza vaccine uptake in rural, suburban, and urban settings in China.

METHODS

We performed a quasi-experimental pragmatic trial to examine the effectiveness of a pay-it-forward intervention (a free influenza vaccine and an opportunity to donate financially to support vaccination of other individuals) to increase influenza vaccine uptake compared with standard-of-care user-paid vaccination among children (aged between 6 months and 8 years) and older people (≥60 years) in China. Recruitment took place in the standard-of-care group until the expected sample size was reached and then in the pay-it-forward group in primary care clinics from a rural site (Yangshan), a suburban site (Zengcheng), and an urban site (Tianhe). Participants were introduced to the influenza vaccine by project staff using a pamphlet about influenza vaccination and were either asked to pay out-of-pocket at the standard market price (US$8·5-23·2; standard-of-care group) or to donate any amount anonymously (pay-it-forward group). Participants had to be eligible to receive an influenza vaccine and to have not received an influenza vaccine in the past year. The primary outcome was vaccine uptake. Secondary outcomes were vaccine confidence and costs (from the health-care provider perspective). Regression methods compared influenza vaccine uptake and vaccine confidence between the two groups. This trial is registered with ChiCTR, ChiCTR2000040048.

FINDINGS

From Sept 21, 2020, to March 3, 2021, 300 enrolees were recruited from patients visiting three primary care clinics. 55 (37%) of 150 people in the standard-of-care group (40 [53%] of 75 children and 15 [20%] of 75 older adults) and 111 (74%) of 150 in the pay-it-forward group (66 [88%] of 75 children and 45 [60%] of 75 older adults) received an influenza vaccine. People in the pay-it-forward group were more likely to receive an influenza vaccine compared with those in the standard-of-care group (adjusted odds ratio [aOR] 6·7 [95% CI 2·7-16·6] among children and 5·0 [2·3-10·8] among older adults). People in the pay-it-forward group had greater confidence in vaccine safety (aOR 2·2 [95% CI 1·2-3·9]), importance (3·1 [1·6-5·9]), and effectiveness (3·1 [1·7-5·7]). In the pay-it-forward group, 107 (96%) of 111 participants donated money for subsequent vaccinations. The pay-it-forward group had a lower economic cost (calculated as the cost without subtraction of donations) per person vaccinated (US$45·60) than did the standard-of-care group ($64·67).

INTERPRETATION

The pay-it-forward intervention seemed to be effective in improving influenza vaccine uptake and community engagement. Our data have implications for prosocial interventions to enhance influenza vaccine uptake in countries where influenza vaccines are available for a fee.

FUNDING

Bill & Melinda Gates Foundation and the UK National Institute for Health Research.

Address: West China School of Public Health, West China Fourth Hospital, Sichuan University, Chengdu, China; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK; Chapel Hill Project-China, University of North Carolina, Guangzhou, China. Electronic address: [email protected].; Chapel Hill Project-China, University of North Carolina, Guangzhou, China; Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, Shanghai, China.; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK; Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong Special Administrative Region, China.; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK; Faculty of Medicine, Central Clinical School, Monash University, Melbourne, VIC, Australia; Melbourne Sexual Health Centre, Alfred Health, Melbourne, VIC, Australia.; Chapel Hill Project-China, University of North Carolina, Guangzhou, China; School of Health and Related Research, University of Sheffield, Sheffield, UK.; Chapel Hill Project-China, University of North Carolina, Guangzhou, China; Duke Global Health Institute, Duke University, Durham, NC, USA.; Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.; Faculty of Public Health and Policy, London School of Hygiene & Tropical Medicine, London, UK.; Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK; Laboratory of Data Discovery for Health, Hong Kong Science Park, Hong Kong Special Administrative Region, China.; Beijing Representative Office, Bill & Melinda Gates Foundation, Beijing, China.; Institute of Population Research, Peking University, Beijing, China.; Chapel Hill Project-China, University of North Carolina, Guangzhou, China; Guangdong Secondary Provincial General Hospital, Guangzhou, China.; Chapel Hill Project-China, University of North Carolina, Guangzhou, China.; Guangdong Secondary Provincial General Hospital, Guangzhou, China.; Zhuhai Center for Disease Control and Prevention, Zhuhai, China; Faculty of Medicine, Macau University of Science and Technology, Macau Special Administrative Region, China.; Vaccination Clinic, Yangshan Health Centre, Qingyuan, China.; Fenghuang Community Health Service Centre, Zengcheng, China.; Xinhua Community Health Service Centre, Guangzhou, China.; Community Health Centre, Guangzhou, China.; Chapel Hill Project-China, University of North Carolina, Guangzhou, China; Guangdong Secondary Provincial General Hospital, Guangzhou, China; Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA. Electronic address: [email protected].; Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK; Chapel Hill Project-China, University of North Carolina, Guangzhou, China; Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA.

DOI: 10.1016/S1473-3099(22)00346-2