A web-based physical activity intervention for Spanish-speaking Latinas: A costs and cost-effectiveness analysis

Background: latinas report particularly low levels of physical activity and suffer from greater rates of lifestyle-related conditions such as obesity and diabetes. interventions are needed that can increase physical activity in this growing population in a large-scale,cost-effective manner. web-based interventions may have potential given the increase in internet use among latinas and the scalability of web-based programs. objective: to examine the costs and cost-effectiveness of a web-based,spanish-language physical activity intervention for latinas compared to a wellness contact control. methods: healthy adult latina women (n=205) were recruited from the community and randomly assigned to receive a spanish-language,web-based,individually tailored physical activity intervention (intervention group) or were given access to a website with content on wellness topics other than physical activity (control group). physical activity was measured using the 7-day physical activity recall interview and actigraph accelerometers at baseline,6 months (ie,postintervention),and 12 months (ie,maintenance phase). costs were estimated from a payer perspective and included all features necessary to implement the intervention in a community setting,including staff time (ie,wages,benefits,and overhead),materials,hardware,website hosting,and routine website maintenance. results: at 6 months,the costs of running the intervention and control groups were us $17 and us $8 per person per month,respectively. these costs fell to us $12 and us $6 per person per month at 12 months,respectively. linear interpolation showed that intervention participants increased their physical activity by 1362 total minutes at 6 months (523 minutes by accelerometer) compared to 715 minutes for control participants (186 minutes by accelerometer). at 6 months,each minute increase in physical activity for the intervention group cost us $0.08 (us $0.20 by accelerometer) compared to us $0.07 for control participants (us $0.26 by accelerometer). incremental cost-per-minute increases associated with the intervention were us $0.08 at 6 months and us $0.04 at 12 months (us $0.16 and us $0.08 by accelerometer,respectively). sensitivity analyses showed variations in staffing costs or intervention effectiveness yielded only modest changes in incremental costs. conclusions: while the web-based physical activity intervention was more expensive than the wellness control,both were quite low cost compared to face-to-face or mail-delivered interventions. cost-effectiveness ranged markedly based on physical activity measure and was similar between the two conditions. overall,the web-based intervention was effective and low cost,suggesting a promising channel for increasing physical activity on a large scale in this at-risk population.