Study design and setting

This study employed a quantitative method using a descriptive cross-sectional study design [32]. Data were collected from the month of October to December 2020, using a structured questionnaire. To aid in the data collection, the lead investigator trained three research assistants. To further maintain confidentiality, the data collection took place in a private area at the chosen ART centre. The questions on medication adherence were asked in the local dialect (Twi) which was then translated into English. It took 15 to 30 minutes to finish the questionnaire on each respondent. All of the questionnaires were checked for accuracy and completeness at the conclusion of each data collection session. Up until the study’s required sample size was reached, this process was continued. Prior to the commencement of the study, pre-testing of the data collection instrument was carried out among 20 PLHIV at Suntreso Government Hospital to verify the data collection tool’s authenticity and reliability.

The research was carried out at the Kumasi South Hospital, a regional hospital in the Ashanti Region of Ghana. This regional hospital is one of the few in the region that offers ART treatment to PLHIV in Ghana. The hospital is at the center of the region, it is raised 250 and 300 m above sea level, and it is settled between longitude 1.300 West and latitude 6.350 North and 6.400 South [11]. Kumasi South Regional Hospital was constructed in 1976, as changed to be the Kumasi South later changed to be the Kumasi South Hospital. In 2002, the hospital was uprated to the status of a regional hospital. The regional hospital, a national health insurance scheme accredited facility, has a 140-bed capacity. Kumasi South Regional Hospital is located in between Agogo and Chirapatre, within the Kumasi Metropolis. About 30.3% of the population in Kumasi Metropolis is in Asokwa where Kumasi South Hospital is located [11].

Kumasi South Hospital is surrounded by seventeen health facilities. Among these facilities, CHAG and one government owned facility each and the remaining are privately owned. In 2017, HIV/AIDS-related conditions were recorded among top ten OPD morbidities. The hospital provides STI, VCT, and ART services for PLHIV.

Sample size

A sample of 420 PLHIV receiving ART was selected using Snedecor and Cochran’s formulae [33] by taking a sample of 0.5% of PLHIV receiving ART and adhering to their medication from a study conducted in Ghana’s Upper West Regional Hospital [28], a 95% confidence level, a 5% margin of error and a 10% non-response rate.

The sample size of the study population was calculated using the Snedecor & Cochran’s formulae [33]:

, where n is the sample size.

$$z = standard deviation$$

, fixed value at 1.96 for 95% confidence interval.

p = proportion of PLHIV on adherence to medication 0.5 (According to research done at the Upper West Regional Hospital in Ghana, the projected proportion of PLHIV who adhered to ART (62.2%) [28].

d = degree of accuracy desired, 0.05.

$$n =\frac^\times 0.5 \left(0.5\right)}^}$$

An additional 10% of sample size was added for non-response.

Therefore, the sample size for this study was set at 420.

Population, eligibility criteria and sampling

The study participants were PLHIV seeking treatment at the Kumasi South Hospital in Ghana. At the time of the study, there were 4,235 PLHIV seeking medical attention at the Kumasi South Hospital. PLHIV, above the age of 18, had used ART for at least six months, and gave their agreement to participate were considered eligible for this study. PLHIV who were seriously ill or admitted during the data collection were not included in the study. A sample size of 420 PLHIV and were on ART completed the survey that gave a response rate of 100% (420/420). The respondents were sampled using a basic random sampling method based on the lottery method. Numbers 0 and 1 were written on each piece of paper totaling 840 and folded into a polythene bag using the lottery method. During the data collection period, eligible participants were allowed to pick one of the folded papers in the polythene bag at random based on their average daily attendance at the clinic. Eligible participants who picked a sheet of paper with 1 written on the sheet were selected to take part in the study. This act was repeated continuously until the required sample size was attained.

Definition of variablesOutcome variable

Medication adherence among PLHIV was the study’s outcome variable. The eight item Morisky Medication Adherence Scale (MMAS-8) questionnaire was used to classify high and low medication adherence. The MMAS-8 is a self-report medication adherence scale with eight items. The scale has good psychometric qualities, according to previous studies [15, 34]. The MMAS-8 was created to provide information on medication-related behaviors that are both unintentional and intentional [35]. The study incorporated the classification of medication adherence into high and low levels of medication adherence from a prior study carried out in India [36].

Explanatory variables

In our estimations, we used nine explanatory variables for the study. These variables included age, gender, marital status, ethnicity, work status, education level, place of residence, religious affiliation, and monthly income. None of these variables were chosen at random; rather, they were chosen based on the findings of previous studies on medication adherence, as well as their theoretical and conceptual implications for HIV/AIDS [25, 31].

Statistical analyses

We employed both descriptive and inferential analytical approaches. During data collection, questionnaires were reviewed for completeness and internal problems. Questionnaires were numbered, sorted, and kept in files. Stata version 14.2 was used to analyze the data. The analysis was done in two main steps. The first step was the description of the sample and prevalence of medication adherence using frequencies and percentages. Second, the factors associated with medication adherencewere assessed using a binary logistic regression analysis (see Table 2) and the results were presented as crude and adjusted odds ratios(aOR) with their respective 95% confidence intervals indicating precision. For all tests, the statistical significance level was set to p <0.05.

Table 1 Socio-demographic information of PLHIV Ethical approval/consideration

The Committee on Human Research, Publications, and Ethics at Kwame Nkrumah University of Science and Technology was first consulted for ethical approval (approved protocol number CHRPE/AP/363/20, approval date October 8, 2020). Permission was also requested from the regional hospital’s administration. After a verbal and written explanation of the methods and risks involved using an information sheet, all participants and subjects were given a consent form. Those who agreed to be part of this study were made either to sign or thumbprint a consent form.