Treatment adherence and cost effectiveness of utilising Community Health Workers in the management of Tuberculosis in Kenya

Abstract

Tuberculosis (TB) is a public health concern in Kenya contributing highly to the disease burden of the country. Effective control of TB requires good treatment adherence. In Kenya Community Health Workers (CHWs) have been utilised for TB management since 1998 to provide directly observed treatment at household level. The use of CHWs has had challenges of implementation including the lack of clear supervisory structures, inadequate provision of incentive for the CHWs, uneven coverage and equity of community health services in the country. As a result, this has compromised the sustainability of their utilisation due to high rates of attrition among volunteer CHWs and in addition there seems to be no evidence to show the effectiveness of using CHWs to promote TB treatment adherence. The overall objective of this study was to determine the TB treatment adherence and cost effectiveness of utilising CHWs in the management tuberculosis. The study was carried out in both urban and rural settings within health facilities utilising CHWs and those not utilising for the purpose of comparison. This was an amphi-directional cohort study that retrieved clinical records for each TB patient from health facility TB treatment registers for the years 2005 to 2010 retrospectively and prospectively collected similar data from patients for the year 2011. The study enrolled 2778 TB patients and among them 1499 (54%) utilized CHWs for their TB treatment. Tuberculosis treatment adherence among patients who had utilized CHWs was 83% compared to 68% in those that did not utilize CHWs (χ2=76.28, df=2, p<0.05). Use of CHWs in the urban set up had a significantly higher adherence rate of 90% compared to the rural set up with 73% (χ2=76.57, df=1, p<0.05). Utilisation of CHWs remained a dominant factor on its own in enhancing treatment adherence in the cohort as revealed by the bivariable and multivariable regression odds ratios; OR 2.25, (95% 1.86 – 2.73) p<0.05 and OR 1.98 (95% 1.51 – 2.5) p<0.05 respectively. Utilisation of CHWs was most effective in the urban set-up, OR 2.65 (95% 2.02-3.48, p<0.05) compared to the rural set up, OR 0.74 (95% 0.56 -0.97) p<0.05. The cost effect analysis revealed that the average cost per Disability Adjusted Life Years (DALYs) averted for treatment success was higher (184 USD) in the cohort that utilised CHWs compared to the cohort that did not utilise CHWs (87 USD). Treatment success rate was significantly higher in the cohort that utilised CHWs; 82.15% compared to 72.25% (p-value <0.05). Utilising CHWs resulted in less DALYs (5688) from death compared to not utilising CHWs (5725). Of the patients who died, a majority died within the first month of their treatment and they were in the cohort that did not utilise CHWs. Utilisation of CHWs in the treatment of TB resulted in better TB treatment adherence compared to no utilisation of CHWs. The urban setting had the best effects on treatment adherence compared to the rural setting. CHWs should be used in the management of TB to enhance treatment adherence and to avert death more so in the early months of TB treatment. Use of CHWs in rural setting requires strategies to improve their mobility and accessibility to patients’ homes. Disability Adjusted Life Years (DALY) is an appropriate tool for evaluation of interventions used in the management of TB. It should be adopted for routine use.