2.1 Settings: The study was conducted in East Shewa zone Oromiya Region, Ethiopia in 2018. Those patients who take ART treatment in five Health centers in East Shewa zone were included.
The study was conducted on patients who were enrolled between October 3, 2011 and March 1, 2013.
2.2 Study Design: Retrospective cohort study design was used to conduct the study.
2.3 Source population: The source population was all people with confirmed HIV positive status in East Shewa Zone, Oromiya region Ethiopia.
2.4 Study population: HIV patients who have started ART service in East Shewa zone between October 3, 2011 and March 1, 2013 with at least two consecutive viral load tests were included.
2.5 Sample size determination and sampling
Two hundred forty three study participants with baseline viral load measurements were included in the study. All patients in the cohort with baseline Plasma viral load were included in the study.
2.6 Data collection tools & procedures
The study used secondary data from a long-running community-recruited prospective cohort of patients living with HIV. HIV Plasma Viral load measurement was taken at enrollment of patient to the study (Baseline), and then after first month, third month, six month and twelve month and eighteen months of ART treatment. Trained clinicians at the start of the study collected demographic and clinical data, including physical examination details by using structured questionnaires. Interview was also used to collect data from patients. After informed consent, data were collected and checked for completeness.
2.7 Laboratory analysis
All laboratory analyses, except TB cultures, were performed at Adama Regional Laboratory. CD4 cell counts were analyzed using BD FACSCalibur cytometer (Becton Dickinson, San Jose, CA). Sputum and FNA samples were analyzed with direct smear microscopy using Ziehl-Neelsen staining and Xpert MTB/RIF (Cepheid, Sunnyvale, CA) for polymerase chain reaction. Liquid cultures for TB were performed at International Clinical Laboratories, Addis Ababa, using a BACTEC MGIT 960 (BD Diagnostics, Franklin Lakes, NJ). Plasma HIV-RNA levels were determined using Abbott Real- Time HIV-1 assay (Abbott Molecular Inc., Des Plaines, IL) with a detection limit of 40 copies/ml. External quality assurance of the regional laboratory is regularly performed by the Center for Disease Control and Prevention (Atlanta, GA).
2.8 Eligibility criteria
Human immunodeficiency virus(HIV)- positive patients presenting to the study health centers between October 3, 2011 and March 1, 2013 were eligible for inclusion given the following criteria met: age 18 years or greater and residency in the catchment area of any of the study sites. This cohort has since been continuously followed. Patients who have started ART since inclusion constitute the study population for the current study, with follow-up data collected until data abstraction on December 31, 2013.
2.9 Exclusion criteria: age less than 18 years old, with current or previous ART, as well as patients on ATT for more than 2 weeks before inclusion in this study were excluded from our study.
Data Quality: Training was given for two data clerks on data management of secondary data obtained from the previous study. Pretest of data collection tools was done before the actual data collection procedure. Double entry of data made by using EPI INFO 7 to minimize error in data management and analysis was done by SPSS version 21.
2.10 Data Analysis
Once data is collected, it was analyzed descriptively to determine the demographic characteristics and distribution of time to PVL. Time to undetectable viral load level was calculated by using Kaplan–Meier to estimate the distribution of PVL in time, and the difference between the survival curves was evaluated with the use of the log-rank test, which is useful for comparing potentially unequal follow-up times of study participants. Cox proportional-hazards regression analysis used to relate covariates with response variable with 95% confidence intervals.
2.11 Ethical considerations
Ethical approval was obtained from Saint Paul’s Hospital Millennium Medical College public health department ethical review committee. Then the approval letter was forwarded to Oromiya regional health office. The study was also cleared from the Ethiopian Ministry of Science (attached file as supplement) and Lund University (attached file as supplement) finally, the approval letter from the regional health office submitted to Adama regional laboratory where the actual study was done. Study participants provided written informed consent.