Methods And Materials
Study Area and Period
Bule Hora general hospital, which is found at 470km from the capital Addis Ababa, is located in the West Guji Zone, Oromia region, South Ethiopia. The hospital has a capacity of 44 beds, providing services for over 1500 patients per year. The hospital has a direct observetion theraphy(DOT) clinic where TB patients are treated and monitored according to the National Tuberculosis and Leprosy Control program guidelines. The study was conducted on the TB treatment outcome and associated factors among TB patients at Bule Hora General Hospital from Janury1-30, 2020.
Study Design
Institution based retrospective cross-sectional document review was been conducted to assess the treatment outcome of TB patients and the associated factors of TB patients’ documents registered from January 1, 2015, to July 2019 at Bule Hora General Hospital.
Population
Source population: The documents of all TB patients who were registered in the hospital from the 1st of January, 2015, to July 2019.
Study population: The documents of the randomly selected TB patients who were registered in the Blue Hora General hospital from the 1st of January, 2015, to July 2019.
Inclusion and Exclusion Criteria
Inclusion criteria
The documents of the registered TB patients at Bule Hora General Hospital were included in this study.
Exclusion Criteria
However, registries in which treatment outcomes were missing and patients were transferred to other districts were excluded from the study.
Variables
Dependent variables
Treatment outcomes are categorized into successful and unsuccessful treatment outcomes. Successful treatment outcomes included “cured” and “treatment completed” cases. Unsuccessful treatment outcomes included “treatment failure” cases, “defaulters,” and patients who “died.
Independent variables
Socio-demographic factors: Sex, age, place of residence, place of residence, and year of treatment.
Clinical factors: Category of patient types of TB, Smear result, HIV status, ART initiated.
Sample Size Determination
For the first objective, the sample size was calculated by using a single population proportion formula based on the assumption of TB Treatment Outcomes in Metema Hospital of 65.3% (P) was used in this case [2].
Where;
- P = TB Treatment Outcomes (65.3%).
- Z = standard score corresponds to1.96.
- d = margin of error 0.05 with a 95% confidence interval was used.
Finally, the sample size of 349 obtained from the first specific objective was used, because it is the largest sample size estimated and would be sufficient for study.
Sampling Technique
Totally 349 TB patients documents reviewed from January 1st, 2015, to July 2019, in the Blue Hora general hospital. The registries which met the inclusion criteria were selected through a systematic sampling technique. This sampling interval (K) will be obtained by dividing the total TB patients by its sample size (k =1869/940=1.99 ∼2. The 1st sample was taken by lottery method from 1; then the data will be collected from the registration log book.
Operational Definition
Successful outcome: if the TB patient will be cured (negative smear microscopy at the end of the treatment and on at least one previous follow-up test) or completed treatment with resolution of symptoms.
Unsuccessful outcome: if the treatment resulted in treatment failure (remaining smear positive after 5 months of treatment), patients are defaulted (patients who interrupted their treatment for two consecutive months or more after registration), or patients died. According to the standard definitions of the National Tuberculosis and Leprosy Control Program guidelines of Ethiopia [5], the following definitions were used for treatment outcomes.
Cured: if the patient had finished treatment with negative bacteriological results at the end of the treatment.
Treatment completed: if the patient had finished treatment, but without bacteriological results at the end of the treatment.
Treatment failure: a patient who, while on treatment, remained smeary positive or became again smear positive at the end of five months or later after commencing treatment or a patient who was PTB negative at the beginning and turned out smear positive at the end of the intensive phase.
Defaulter: a patient who had been on treatment for at least 4 weeks and whose treatment was interrupted for 8 or more consecutive weeks.
Died: if the patient died from any cause during the treatment.
New case: a patient who had never had treatment for TB or had been on anti-TB treatment for less than four weeks.
Three types of TB will be considered in this study. These are smear positive pulmonary TB (PTB+), smear negative pulmonary TB (PTB-), and extrapulmonary TB (EPTB).
Smear positive pulmonary TB (PTB+): a patient who had at least 2 initial smear examinations positive for AFB by direct microscopy or one initial smear examination positive and culture positive or one initial smear positive and radiographic abnormalities consistent with TB.
Smear negative pulmonary TB (PTB-): a patient who had three initial smear examinations negative for AFB and no response to the course of broad-spectrum chemotherapy and again 3 smear examinations negative by direct microscopy and radiographic abnormalities consistent with PTB and three initial smear examinations negative by direct microscopy but positive by culture and decision by a clinician to treat with anti-TB
extra pulmonary TB (EPTB): a patient who had TB in organs other than the lungs proven by one culture-positive specimen from extra pulmonary sites or histopathological evidence from a biopsy or TB based on strong clinical evidence for active EPTB and the decision by a physician to treat with anti-TB.
Data collection tools and technique
The data was collected by using a pretested structured data extraction format. The standard TB registry, laboratory findings, and monthly cohort follow-up form were reviewed to generate the required data. The standardized checklist was used including all important socio-demographic data, clinical characteristics (sputum smear, type of TB, patient type, HIV status, drug regimen, and treatment outcomes), laboratory findings, and follow-up data. Data were collected by four BSc. Nurses who have had training on comprehensive TB care and experience in data collection.
Data quality assurance
To improve the quality of the data, the questionnaire was pretested a week before the actual data collection time on a 5% sampled unit in a Qarca hospital and modification was done accordingly. The supervisor and data collectors were trained for two days before data collection. The proper supervision of data consistency and completeness was undertaken throughout the data collection and analysis. The data collectors discussed the methods of data collection and the questionnaire will be checked daily for completeness during data collection.
Data processing and analysis
Data was entered into the computer using Epi-data software version 3.2 and exported to SPSS software version 22 for analysis. Appropriate descriptive statistics such as mean (with standard deviation), median (with interquartile range [IQR]), and frequency (with percentages) were used to describe the study population in relation to relevant variables. Bivariate and multivariate analyses with 95% confidence intervals were employed to infer associations between the independent and dependent variables. Binary logistic regression was used to calculate the crude odds ratio (COR) with a 95% confidence interval. Each variable was entered into a logistic regression model to determine the presence of a statistically significant association with the outcome variable. Multicollinearity among selected independent variables was checked through variance inflation factor (VIF). The explanatory variables with a P-value≤ of 0.2 in the bivariate analyses were included in the final multivariable logistic model to identify the independent predictors of TB treatment outcome. AP value < 0.05 was considered statistically significant. The assumption on the fitness of goodness of the final model was checked by Hosmer and Lemeshow test.
Ethical consideration
This study was conducted in accordance with the research ethics of the University of Bule Hora. Ethical clearance was obtained from the institutional ethical review board of the University of Bule Hora. As this is a retrospective study, the consent of patients was not obtained. However, patient information has been handled anonymously with assuring confidentiality.