Treatment outcome of tuberculosis patients at Adare general Hospital,Hawassa, Southern Ethiopia (A five year retrospective study)

Objective This institution based retrospective study was conducted to determine the treatment outcome of TB patients and investigate and associated risk factors among TB patients registered at Adare general Hospital, Southern Ethiopia. Result Among 1122 cases 620 (55.3%) were male, 748(66.7%) were from urban areas, 319 (28.4%) were smear positive, 352 (31.4%) were smear negative and 451 (40.2%) were extra pulmonary patients. Of the 1122 284 (25.3%) were cured, 753(67.1%) completed treatment, 29(2.6%) defaulted, 53(4.7%) died and 3 (0.3%) had treatment failure. The overall mean treatment success rate was 92.4%. The risk of unsuccessful TB treatment outcome was significantly higher among TB patients from rural areas (AOR = 0.435, 95% CI: 0.279, 0.679); patients with extra pulmonary TB (AOR = 0.877, 95% CI; 0.671, 1.146), and HIV positive TB patients (AOR = 5.478, 95% CI; 3.474, 8.639) were more likely to have poor treatment outcomes as compared to their counter parts.

Background Tuberculosis, which caused by Mycobacterium Tuberculosis [1], is a major public health problem in the world being among the ten top leading diseases that cause death [2]. Ten million people were infected and 1.6 million died due to TB [3]. About 56%cases were from South-East Asia and Western Pacific Regions and 29% were from Africa where the highest rate of death occur [4].
Among 30 high TB burden countries globally, Ethiopia ranks seventh and theestimated TB prevalence rate in the country was 27/1000000 population with an estimated incidence rate of 224 per 100,000 population [3]. Annually there are an estimated 5000 or more MDR-TB cases, hence, among 27 high MDR-TB burned countries, Ethiopia was placed at rank of fifteenth [5]. Minister of health indicated that TB was the leading cause of morbidity, the third leading cause of hospital admission, and the second cause of death [6]. Globally accepted TB intervention strategy was Directly Observed Treatment Short Course (DOTS). Since, 1992 DOTS strategy was started was implemented at national level [6] and all public, private and non-governmental health facilities provide the service [7]. Health institution based studies conducted in the country indicated the treatment outcome showed increment after the delivery of DOTS services [8][9][10][11][12], though there were various challenges [13,14]. Adare General Hospital implemented DOTS program starting national scale up period, however the institutional status of treatment outcome and associated challenges were not studied so far. Therefore, this retrospective study was aimed to assess the treatment outcome of TB patients and identify associated risk factors among TB patients in Adare general Hospital.

Study area and design
Hawassa, is located about 275km South of Addis Abeba, it lies at 7 0 5' latitude N and 38 0 29' Longitude E at an altitude of 1708 masl (meter above sea level). Based on 2007 national census Hawassa town has 329, 734 inhabitants, 169, 677 were males and 160, 057 were females. Adare general Hospital is located at the center of the city and has 70 functional beds. The hospital has one DOTS clinic that performing activities based on the national TB Program guideline [6].Institutional based retrospective study was conducted by reviewing registration book of tuberculosis patients registered and treated from 2014-2014 at DOTS clinic of Adare Hospital.

Data collection and analysis
Data with complete information of TB patients registered at DOTS TB Clinic were collected retrospectively using a structured checklist.Data was entered and analyzed using SPSS version 20 statistical software. Frequency and percentage of data was determined using descriptive statistics. Bivariate and multivariate analysis were computed to asses the association between TB treatment outcomes and independent variables. Crude and adjusted odd ratio were computedto evaluate the strength of association. P < 0.05 was considered as statistically significant.

Operational Definition
The following clinicalcase and treatment outcome operational terms were used in this article based on standard definitions NLCP adopted from WHO [6] Smear-positive pulmonary TB (PTB+): A patient with at least two sputum specimenswhich were positive for acid fast bacilli (AFB) by microscopy, or a patient with only one sputumspecimen which was positive for AFB by microscopy, and chest radiographic abnormalitiesconsistent with active PTB.

Smear-negative pulmonary TB (PTB-):
A patient with symptoms suggestive of TB, withat least two sputum specimens which were negative for AFB by microscopy, and with chestradiographic abnormalities consistent with active PTB, or a patient with two sets of at least twosputum specimens taken at least two weeks apart, and which were negative for AFB by microscopy,and radiographic abnormalities consistent with PTB and lack of clinical response to oneweek of broad spectrum antibiotic therapy.

Extra pulmonary TB (EPTB):
This included TB of organs other than the lungs, such aslymph nodes, abdomen, genitourinary tract, skin, joints and bones, the meninges and others.Diagnosis of EPTB was based on fine needle aspiration cytology or biochemical analyses of cerebrospinal/pleural/ascitic fluid or histopathological examination or strong clinical evidenceconsistent with active EPTB, followed by a decision of a clinician to treat with a full course ofanti-TB chemotherapy. In all the cases of EPTB, sputum examinations and chest radiographswere used to rule out involvement of the lung parenchyma. This hospital lacks the facilities forculture and drug susceptibility testing.

Categories of treatment outcomes
Successful outcome: If TB patients were cured (negative smear microscopy at the end oftreatment and on at least one previous follow-up test) or completed treatment with resolutionof symptoms.
Unsuccessful outcome: If treatment resulted in treatment failure (remaining smear-positiveafter 5 months of treatment), defaulted (patients who interrupted their treatment for twoconsecutive months or more after registration), or died.

Treatment outcome of the participants
The treatment outcome of most the cases was promising, (67.1%) were completed anti-TB treatment and (25.3%) cured. Treatment failure, died and defaulters were (0.3%), (4.7%) and (2.6%), respectively. Majority of treatment failure and defaulter were in the age rage of 45-64 years and the high rate of death 15% was registered by HIV/TB co-infected patients ( Table 2).

Treatment success rate and its associated factors
The treatment success rate was 51% in males and 41.4% in females. Majorities 63% of the patients with successful outcome were urban residents. The highest treatment success rate was observed in the age group 0-14 and 45-54 years. The treatment success rate of EPTB, PTBand PTB + patients was 37.3%, 29.2% and 25.9% respectively. The success rate among new and relapse cases was 88.6% and 3.8% respectively.
HIV status, residence, and type of TB showed significant association with treatment outcome P < 0.05. The risk of unsuccessful TB treatment outcome was significantly higher among TB patients from rural areas (AOR = 0.435, 95% CI: 0.279, 0.679).
Patients with EPTB were more likely have poor treatment outcome as compared to patients with PTB + and PTB -(AOR = 0.877, 95% CI; 0.671, 1.146). HIV positive TB patients were more likely to develop risk of poor treatment outcomes as compared to their counterparts (AOR = 5.478, 95% CI; 3.474, 8.639) ( Table 3).

Discussion
Males account for more than half of the study participants, correspondingly studies conducted in different health institutions in the county also indicated that more males were involved [15,16]. However finding from studies conducted in Gambella [17] and Raya Kobo [18]  [27]. Which, might be due to a better supervision and health education activities.
Treatment failure rate 0.3% was in consistent with the rate of reported from other study in Ethiopia 0.3% [15], and higher than treatment failure rate in Malaysia 0.2% [33]. Nonetheless the rate observed in this study was lower than findings from  [30]. The risk of poor treatment outcomes

Conclusions
As the five years retrospective study indicated the DOTS strategy improved TB treatment success in Adare hospital. Treatment outcome rate of registered patients in the study area was high and has met the target success rate set by WHO.
Residence, HIV status and TB category are main predictors for unsuccessful treatment outcome. Hence, awareness creation through health education for rural patients and regular follow of patients with unsuccessful outcome on the way of treatment is essential.

Limitations
A limitation of this study could be that since the data collected is retrospective secondary data and the data source (which was the standard TB register) did not capture detailed information, hence in some cases there was missing and/or inaccurate data. Moreover, the data was collected from one site, Adare Hospital which might not be representative to give general conclusion since patients from other facilities have different profile.

Consent for publication
Not applicable

Availability of data and materials
All data generated and analysed during the present study are included in this manuscript and accessed from corresponding author as required.

Conflict of interests
The authors declare that they have no conflict of interests.

Funding
The research fund for this investigation was obtained from Hawassa University, vice president for Research and Technology Transfer office. However, the office has no role in the design of the study and data collection, analysis, and interpretation of data and in writing the manuscript and in deciding to publish.

Authors' contributions
BT and ZB conceive the idea and developed proposal. BT collected the data, entered the data and conducted data analysis. ZB and SA analyze the data further, interpreted the results and reviewed the initial and final drafts of the paper; finally SA critically reviewed and wrote the manuscript and submit for publishing. All authors read andapproved the final manuscript ahead of submitting for publication.