Determinants of delayed diagnosis and treatment of tuberculosis in Cambodia: a mixed-methods study

Cambodia is among the 30 countries in the world with the highest burden of tuberculosis (TB), and it is estimated that 40% of people with TB remain undiagnosed. In this study, we aimed to investigate the determinants of delayed diagnosis and treatment of TB in Cambodia.

This mixed-method explanatory sequential study was conducted between February and September 2019 in 12 operational districts in Cambodia. It comprised of a retrospective cohort study of 721 people with TB, followed by a series of in-depth interviews. We assessed factors associated with time to TB diagnosis and treatment initiation using Cox proportional hazards model. Subsequently, we conducted in-depth interviews with 31 people with TB purposively selected based on the time taken to reach TB diagnosis, sex, and residence. Transcripts were coded, and thematic analyses were performed.

The median time from the onset of symptoms to TB diagnosis was 49 days (Interquartile range [IQR]: 21-112). We found that longer time to diagnosis was significantly associated with living in rural area (Adjusted hazards ratio [aHR] = 1.25; 95% confidence interval [CI]: 1.06-1.48); TB symptoms-cough (aHR: 1.52; 95% CI: 1.18-1.94), hemoptysis (aHR 1.32; 95% CI: 1.07-1.63), and night sweats (aHR: 1.24; 95% CI: 1.05-1.46); seeking private health care/self-medication (aHR: 1.23; 95% CI: 1.04-1.45); and higher self-stigma (aHR: 1.02; 95% CI: 1.01-1.03). Participants who received education level above the primary level were inversely associated with longer time to diagnosis (aHR: 0.78; 95% CI: 0.62-0.97). The median time from TB diagnosis to the initiation of treatment was two days (IQR: 1-3). The use of smear microscopy for TB diagnosis (aHR: 1.50; 95% CI: 1.16-1.95) was associated with longer time to treatment initiation. Seeking private health care and self-medication before TB diagnosis, lack of perceived risk, threat, susceptibility, and stigma derived qualitatively further explained the quantitative findings.

TB diagnostic delay was substantial. Increasing public awareness about TB and consciousness regarding stigma, engaging the private healthcare providers, and tailoring approaches targeting the rural areas could further improve early detection of TB and narrowing the gap of missing cases in Cambodia.