Study design, period and area
Hospital based unmatched case control study design was conducted in Southern Nation, Nationalities and Peoples Region (SNNPR) to determine risk factors associated with MDR-TB in comparison to drug susceptible TB (DS-TB) patients. The study was conducted from March to April, 2019.
A population projection figure of 2012 based on 2007 national population and housing census, the population of the region was estimated to be 17,359,008(18). Since 2014, there were six public hospitals serving as MDR/TB Treatment Initiation Center (TIC) in the Region. We selected three of these TIC, Namely: Yirgalem General Hospital, Quuen Eleni Memorial Hospital and Butajira General Hospital as our study sites. All the three hospitals have Directly Observed Treatment (DOT) center and a separate MDR/TB treatment initiation centers to manage drug susceptible tuberculosis (DS-TB) and MDR-TB patents respectively. Diagnosis and treatment of both drug susceptible and MDR-TB performed according to the guidelines for clinical and programmatic management of TB, leprosy and TB/HIV in Ethiopia(19).
Source population
All confirmed MDR-TB patients from peripheral districts and Drug Susceptible TB patients at the end first line anti-TB treatment attending Yirgalem, Butajira and Queen Elen Memorial Hospitals.
Study population
All confirmed MDR-TB patients from peripheral districts and Drug Susceptible TB patients at the end first line anti-TB treatment during study period attending Yirgalem, Butajira and Queen Elen Memorial Hospitals.
Eligibility criteria
MDR-TB confirmed patients by culture and/or drug susceptibility testing, and patients taking treatment and drug-susceptible TB patients declared cured or treatment completed at the end of first line ant-TB treatment were included in the study. Age below 15 years old, patients from main urban centers and seriously ill patients were excluded.
Sample size determination
Sample size was determined by a double population proportion formula. Epi-Info version 7.2.2.6 was used to calculate the number of study participants. Contact with a known TB patient in previous study that was conducted in East Shoa in Oromia(11) was used for sample size determination based on the following assumptions: 95% confidence level at power of 80%, with the ratio of 1:1 case to control, percent of control exposed 39.7 and percent of cases exposed 61.6. The final sample size was 180 (90 cases and 90 controls).
Sampling technique
Cases were selected by stratified random sampling technique by considering the hospitals as strata for in-patient (admitted) and on follows up. Controls were recruited by stratified random sampling technique from the patients completed first line anti-TB drugs.
Sampling procedure
A total of 135 MDR-TB patients were from peripheral districts and 105 patients were eligible to complete first line anti-TB treatment during the study period. A stratum was made based on the hospital the patients attending. A proportional allocation to the size was made by a lottery method.
Independent and dependent variables
The outcome variable was multidrug resistant tuberculosis status (cases or controls). The predictor variables were sociodemographic characters like age, sex, marital status, occupation, educational status, monthly income, alcohol consumption, tobacco smoking, Khat chewing, imprisonment, staying in a refugee camp, consumption of raw meat and milk, living with cattle or domestic animals, nutritional status, site of TB, smear status, contact history, the history of previous TB treatment, hospitalization for TB, disclosure of TB status, co-morbidity, and HIV sero-status.
Data collection instrument
Data were collected by using pre-tested and structured questionnaire. Data collection tool was adopted from previous studies (10, 11, 13, 20-23).
Data quality assurance
Pre-test was carried out in All Africa Leprosy and TB Rehabilitation, and Training Center (ALERT) hospital before 1 week of main study. The questionnaire prepared in English was translated to Amharic then retranslated to English for consistency. Training was provided to 6 B.Sc nurse health professionals who collected data before the beginning of data collection. After completing the interview session, additional data were collected from the MDR-TB and drug susceptible TB registers. To maintain validity of data, regular supervision was made by the principal investigator. The principal investigator and trained supervisors checked the completeness of each questionnaire and data accuracy on daily basis.
Data processing and analysis
The data were entered into Epi data 4.4.3 then exported to SPSS 24 for cleaning and analysis. The variables were described by frequencies, percentages, presented in tables and graphs. Median for income and age was calculated. Bivariate analysis was done to select the variables for multivariable analysis. The data were analyzed by logistic regression model. Variables with p-value <0.25 in bivariate analysis were entered to multivariable logistic regression to control confounding. Determinants with P<0.05 was considered as having a significant association with MDR-TB and AOR with 95% CI was used to measure a degree of association.
Ethical clearance
Ethical clearance was obtained from School of Nursing and Midwifery, Addis Ababa University, Research Ethics committee. The purpose of the study was explained to each study participant before data collection. Only those who gave consent to participate in the study was included in the study. The study participant was coded anonymously and confidentiality of information was maintained.