Factors associated with mortality among Tuberculosis patients on treatment in Limpopo Province, South Africa, from 2013 to 2018

Abstract

Background Tuberculosis is among the leading causes of morbidity and mortality worldwide, despite the availability and implementation of directly-observed treatment, and all other intervention strategies for its treatment; more than 70% of deaths among tuberculosis patients occurs during the first 2 months of treatment. This study, therefore, aims at identifying factors that contribute to death among tuberculosis patients during treatment, in Limpopo Province, South African, between 2013 and 2018. Method A quantitative retrospective cohort study design, using secondary data was applied. Data on all patients who were registered for tuberculosis treatment in the Province from 2013 to 2018 was extracted from the electronic tuberculosis register (ETR.Net) into an excel spread sheet; Statistical Package Social Science version 20, and Statistics and Data version 12 were used for analysis. As part of the descriptive statistics, the Chi square test (χ2) was used to establish the association between other variables and the main outcome - death. Summary tables described the variables in terms of their frequency and univariate, as well as multivariate models were developed in order to identify the factors that significantly impacted on the death of these patients. Results A total of 79589 patient‟s records were selected for the study; of these 48892 (61.4%) were HIV positive. Their treatment outcomes showed that patients cured were 80.6%, died were 12.5% (which is still high), the defaulted were 5.7%, the MDR cases were 0.2, the Rifampicin resistance were 0.3% and 0.6% for treatment failure. There is a gradual decrease in the death rate, from 2013 at 14.7 % to 7.4% in 2018. There was a statistically significant association between death and gender. The mortality rate among the male gender was 12.8% and for the female gender was 12.2%, with a Chi square value of 4.4 and a p value of 0.032. There was a clear association between CD4 cell count range among TB patients and mortality. The mortality among TB patient with a CD4 count less than 50 was 20.4%, which V was the highest and the difference was statistically significant with a p value less than 0.0001. Mortality among the other groups was much lower and decreased progressively with the lowest mortality rate among those with a CD4 cell count higher than 350 at 3.3%. The Kaplan-Meier Survival analysis provides special techniques that are required to compare the risks for death associated with different groups (in this case, HIV positive and HIV negative patients) where the risk changes over time in measuring survival time. The case processing summary shows that the number of events in both HIV negative and HIV positive groups were almost similar and 91.5% of the HIV negative were censored as compared to 85%. Discussion A retrospective review of data collected on patients receiving anti-TB treatment was conducted in Limpopo Province where TB incidence rate is the highest compare to all provinces of South Africa. A low treatment success rate was observed in this study; the treatment outcomes showed that patients cured were 80, 6 %, and patients who died were 12, 5%. In Cameroon, patients‟ treatment success outcome was 76.4% and 6.9% died. There was a statistical significant association between death and gender. The gender that had high mortality among TB patients on treatment, between the years 2013 -2017 was the male gender.