Factors associated with self-medication in users of drugstores and pharmacies in Peru: an analysis of the National Survey on User Satisfaction of Health Services, ENSUSALUD 2015

Introduction

Self-medication is a practice that represents a public health problem worldwide¹, mainly in developing countries, where it is an important issue for the health systems. The World Health Organization (WHO) defines self-medication as the selection and use of medicines by individuals to treat self-recognized illness or symptoms². In addition, the concept of responsible self-medication (RSM) is based on the treatment of diseases and conditions using medicines that do not require a prescription for their sale, due to their safety and effectiveness when correctly used². For that reason, there are over the counter (OTC) medicines, which would respond to the concept of RSM³. To study these behaviors is relevant in developing countries of Latin America.

The frequency of self-medication differs according to the country and context evaluated. Studies have reported self-medication prevalence ranging from 27% to 90.1%. In Asia, a study made in India reported a prevalence of 71%⁴, while in Iran it was 35.4%⁵. In Europe, research studies in Spain reported a prevalence between 14% and 90.1%^6–8. In Latin America, Colombian studies presented prevalence ranges from 27.3% to 55.4%^9–11, whereas in Brazil, it oscillated from 31% to 86.4%^12,13. In Peru, a previous work found a self-medication prevalence of 56.7% in an urban area of Lima¹⁴. Then, we consider relevant to research the prevalence of self-medication since it has benefits and risks¹⁵.

Self-medication practice can entail suffering serious adverse effects. In addition, the concomitant use of several medicines may develop interactions that could increase those adverse effects^1,16. Even OTC medicines used inappropriately and irresponsibly can represent a risk for the consumer^1,15,17. Among the main benefits of the RSM, we can mention the increased access to pharmaceutical products, the reduction of unnecessary medical appointments, and of the expenses in healthcare services by the government¹⁵. For this reason it is important to evaluate the factors associated with the irresponsible self-medication practice (ISM)¹⁸.

Among the main conditions associated with self-medication practice are demographic, social, cultural, personal and health system factors. Age, sex, socio-economic status and educational level are frequently related to self-medication practice¹⁰. Among the personal factors associated with self-medication are having good results after self-medication, the belief of having experienced manageable similar symptoms previously, the fear of being diagnosed with a serious disease and the need to alleviate symptoms prior using healthcare services^16,19,20. Regarding healthcare system, it has been described that self-medication is related to the easy access to medicines in drugstores and pharmacies and the lack of access to healthcare services, which in turn, is associated with the lack of a health insurance¹⁹. Thus, it is proved the multifactorial character of the self-medication practice.

In this context, despite its relevance, we have not found nationwide studies that had evaluate the frequency of self-medication in users of drugstores and pharmacies in Peru. The objective of this study was to estimate the frequency of RSM and ISM, and to identify the factors associated with such practice in a population-based sample.

Methods

Population, sample and sampling

The population was composed of clients of drugstores and pharmacies, who were surveyed after the purchase of a medicine. In total, the fourth questionnaire included 3863 participants. The sample size calculated of 3,863 participants represented an expanded population of 3,078,419 people; participants were not excluded due to lack of data or incomplete records (Figure 1). The calculation of the sample size used a design effect of 1.2 and a satisfaction possibility of 30% according to the results of the survey ENSUSALUD 2014; assuming a confidence level of 95%. Since our study was a secondary analysis, we calculate the statistical power and the result was 99%.

Figure 1. Flowchart of participants selection, ENSUSALUD 2015.

The sampling was probabilistic, stratified, for each one of the 25 regions of Peru, and two-staged. Drugstores and pharmacies were considered as primary sampling units, while users who went to such establishments were the secondary sampling units.

Results

Discussion

This study found that three-quarters of the participants self-medicated and one out of two of the total population practiced ISM. Also, two out of three participants who irresponsibly self-medicated were not asked for the corresponding prescription when purchasing the medicine they wanted. The factors associated with increased RSM and ISM practice were male gender and not having health insurance. In addition, living in the Highlands was associated with RSM. On the other hand, being 40 to 59 years old or 60 to older were associated with a lower frequency of RSM and ISM.

Our study showed that the prevalence of self-medication was 74.8%, which was higher than that reported by Faria-Domingues et al.²³ in a systematic review that aimed to assess the prevalence of self-medication in adult population from Brazil. This review found that one-third of the population self-medicates. Likewise, the prevalence in our study was higher than that found by Jerez-Roig et al.²⁴ in a systematic review that included 28 studies predominantly from Brazil and the United States. Such review showed that the prevalence of self-medication in individuals aged 60 or older was on average 38%, and ranged from 4 to 87%. In our study, the participants were over 18 years old, this may explain the above-average prevalence mentioned in the systematic review of Faria-Domingues et al.²³.

Evidence from previous studies shows that self-medication frequency is higher in low and middle-income countries than in developed countries²⁰. Variable prevalence rates have been reported in Latin America, Africa and Asia (27%-86.4%)^{4,5,9–13,25}. However, percentages ranging from 8% to 14%¹ are reported in developed countries (United Kingdom, Italy, Switzerland, Belgium, Germany, France, United States of America and the United Kingdom). This is due to the fact that in these countries there is an adequate supervision when supplying OTC drugs. Therefore, most of these prevalence’s correspond to the purchase of OTC medicines. It has also been reported that certain types of drugs such as antibiotics and NSAIDs are available as OTC drugs, causing adverse reactions due to misuse^1,16,19,20.

The most requested drugs by the participants were NSAIDs, antibiotics and analgesics/antipyretics/corticoids. A previous study in Peru found that NSAIDs were also the most acquired drugs (30%)¹⁴. On the other hand, in a study carried out in Colombia, the most commonly used drugs were analgesics/antipyretics (44.3%), NSAIDs (36.4%) and antihistamines (8.5%), which goes according to our findings¹⁰. These findings are similar because analgesics/antipyretics/corticoids, NSAIDs, antihistamines, and antibiotics are the most frequently used drugs described in other studies^7,9,26–31 and are used to treat common symptoms that people do not consider sufficient reason to see a doctor; therefore, they tend to self-medicate.

Our study showed that the male gender reported a higher self-medication frequency. However, studies such as those of Jerez-Roig et al.²⁴ and Lukovic et al.³² reported that the female gender is associated with a higher prevalence of self-medication practice. Our findings are further supported by the study of Quédraogo et al.³³, who described that the self-medication practice was found to be associated mostly with the male gender in rheumatic diseases. However, this study was only carried out in an urban area; therefore, the results could vary or not be extrapolated at rural or national level, as is the case of our research.

In Peru, a study conducted in a district of Metropolitan Lima by Hermoza-Moquillaza et al.¹⁴ described that self-medication percentage was higher in the male gender. However, this study did not carry out regression models with multiple variables, which would give our study an innovative character because it is a population-based study and includes a multivariate analysis. On the other hand, findings in Peru regarding a lower self-medication prevalence in females can probably be explained by the sexist nature of its society³⁴. We consider that, in sexist societies, the family structure implies that women are relegated to housekeeping and taking care of children, which, together with the repression from their partner, would reduce their probability to self-medicate and even access to health services. This association could also be explained because men would spend most of their time at work and would not have enough time to go to a health center, having less access to health services^35,36, so they would resort to the practice of self-medication. Besides, the high prevalence of NSM in women and older adults could be explained due to their poor health status, which would predispose them to use frequently health services and receive a medical prescription. Furthermore, older adults need to acquire several drugs for the best management of their comorbidities³⁷.

A higher self-medication prevalence was found in participants without health insurance compared to those with SIS. Not having health insurance prevents patient from accessing health services, with the option of self-medicate in drugstores and pharmacies. In this context, some studies have associated the difficulty in obtaining a medical appointment with the self-medication practice, as well as an adverse financial situation^38–41. However, in some health systems, having a health insurance does not guarantee a lower self-medication prevalence. Thus, no statistically significant differences were found between people who have SIS or EsSalud and the practice of RSM or ISM. This situation could be explained by the fact that those with SIS can easily make an appointment as an outpatient, but they would not have an adequate access to medicines²¹. In contrast, the situation with social security is the opposite, people with this insurance can benefit from the adequate supply of medicines under this contributory system. However, making an appointment as an outpatient would represent a more problematic situation compared to people with SIS⁴². Both situations would eventually lead to RSM or ISM. A similar case occurs in China, where long waiting times (more than half a day), and an expensive medical care, would lead to a high self-medication prevalence of antibiotics in college students⁴³. Similarly, in Saudi Arabia, there was a positive association between the difficult access to health services and the self-medication practice of patients in primary care centers⁴⁴.

Peru has a fragmented health system, which is divided into two sectors: public and private^45,46. The public sector is also divided into subsidized or indirect contributory system and direct contributory or social security system. In the public sector, the government provides medical services (SIS) to the population living in poverty through the MINSA-GR establishments. The social security system is intended for citizens with formal employment. It has two subsystems: EsSalud and the private health care providers. Furthermore, the FF.AA.PP have their own health subsystem. Finally, the private sector is divided into the for-profit system (private insurance companies, private clinics) and non-profit system (NGOs)^45,46. The process of universal health insurance in Peru has begun since 2009 and seeks to ensure that more Peruvians have medical insurance based on an essential plan. However, this process is still being implemented and many citizens do not have health insurance yet⁴⁷. This leads to a lack of access to medical services and a high prevalence of ISM in Peru^48,49.

We found an association between the lack of request for prescription by the pharmacist when purchasing the medicine and self-medication in the bivariate analysis. This situation is evidenced by the inadequate distribution of prescription medicines, as is the case with the OTC sale of antibiotics in Peru, despite the current regulations^14,50. This situation also occurs in other Latin-American countries such as Chile and Colombia, where there are regulations to prevent the free distribution of antibiotics; however, the results are not evidenced over the years^26,51. We also observed a small percentage of participants (6%) who were asked for a prescription despite purchasing an OTC medicine. This would reflect a professional malpractice by pharmacists in Peru.

This study has limitations: 1) since it is a secondary analysis of a survey designed to assess user’s satisfaction of health services, it was not necessarily conducted to answer our research question; however, the questionnaire has been designed and validated by the INEI staff; 2) the cross-sectional design of this study does not allow us to establish a causal relationship among the factors associated with self-medication. However, it allows us to find the association and identify the markers that could be used by healthcare managers to carry out future public health interventions⁵².

In conclusion, there is a high self-medication frequency in Peru, mostly with medicines that are not authorized for OTC sale. It is important to carry out public health interventions in order to reduce the ISM frequency in Peru. There is also a need for educational reforms aimed at raising awareness of the consequences of this irresponsible practice. Similarly, respective measures should be taken to improve the coverage of universal health insurance, thus preventing people from resorting to ISM due to lack of access to medical services. Finally, efforts should be made to integrate druggists and pharmacists into regulatory entities in order to control OTC and uncontrolled sales of prescription drugs. Self-medication could represent a quick and economical solution for users, but it must be practiced within a responsible context.

Data availability