Study setting
The study was conducted in all the five main prisons (Bauchi, Azare, Ningi, Misau and Jama’are) in Bauchi State. These prisons lock-up above its maximum capacity and the holding cells are usually overcrowded. The prisons have clinics with various cadre of healthcare workers (Doctor, nurses, community health officers, pharmacy assistant, dental assistant, community health extension workers, laboratory technologists and radiographer) that provides mainly curative services for inmates, staff and staff relations. These prisons have no diagnostic capacity for TB. On reception into the prisons, inmates are not offered screening for active tuberculosis. Those suspected to have TB were referred to health facility close to the prison for evaluation and on diagnosis, they are placed on Anti-TB drugs for the full course. Their treatment was continued in the prisons under the supervision of the prison health personnel.
Study design and population
We conducted a review of the treatment outcomes of all prison inmates treated for TB from January 2014 to December 2018 in all five prisons in Bauchi State. All prison inmates treated for TB with Anti-TB drugs from January 2014 to December 2018 were included. Inmates with missing variable(s) of interest in the TB treatment register were excluded (Figure 1).
Data tool and collection
The data source was the TB treatment register and patient health records in the five selected prisons. Data were extracted using a structured checklist. The checklist collected information on age, pretreatment weight, duration of imprisonment, TB class (Smear Positive Pulmonary Tuberculosis [SPPTB], Smear Negative Pulmonary Tuberculosis [SNPTB], Extra-Pulmonary Tuberculosis [EPTB]), treatment category (New, Retreatment, Unknown), HIV status, treatment outcomes (cured, treatment completed, failure, lost to follow-up, transferred out and died), from the TB treatment registers in the various study prisons by five trained healthcare workers (HCWs). The five HCWs (one from each prison) were trained for a day on how to collect the data and use the checklist. The principal researcher daily reviewed the filled format and strictly supervised the trained research assistants. Data were collected over a period of five weeks. Each prison was assigned a week; this enable the researcher to supervised the process of data abstraction.
Measurement
The dependent variable (treatment outcome) was dichotomized as successful (cured and treatment completed) and unsuccessful (treatment failure, lost to follow-up, transferred out and died) and the independent variables were socio-demographic characteristics (age, weight, duration of incarceration) and clinical characteristics (HIV status, TB class and treatment history). The following operational definitions were adopted for drug-susceptible TB.21
Cured: A PTB case with bacteriologically confirmed TB at the beginning of treatment who was smear or culture negative in the last month of treatment and on at least one previous occasion.
Treatment completed: A TB case who completed treatment without evidence of failure but without records to show that sputum smear or culture results in the last month of treatment and on at least one previous occasion were negative, either because tests were not done, or results were unavailable.
Treatment failure: A TB case whose sputum smear or culture is positive at month 5 or later during treatment.
Lost to follow-up: A TB case who did not start treatment or whose treatment was interrupted for two consecutive months or more.
Not evaluated: A TB case for whom no treatment outcome is assigned. This includes cases transferred out to another treatment unit as well as cases for whom the treatment outcome is unknown to the reporting unit.
Died: A TB case who dies for any reason during treatment.
New TB patient: A TB case who has not previously been treated for TB and is now diagnosed and has started the current treatment.
Relapse/Retreatment: A TB case who was previously treated for TB and was declared cured and now diagnosed and started the current treatment.
Data analysis
Extracted data were checked for its completeness, correctness and analyzed using Epi-info software version 7.2.2.6. Descriptive statistics was used to generate summary frequencies, percentages, and means. Bivariate analysis was performed to measure association between treatment outcome and independent variables and variables that were significant at bivariate analysis were included in multivariate logistic regression model to identify predictors of treatment outcomes at 95% confidence intervals (CIs).
Ethical consideration
Ethical approval was obtained from the Bauchi State Health Research Ethics Committee. Permission was sought and obtained from the Controller of Prisons, Bauchi State command, where the aim and objectives of the study were explained. The information obtained was made anonymous and de-identified prior to analysis to ensure confidentiality.