Beneficiaries were mainly adults, with functional disability and a low level of education, unemployed, and with one or more children. There is wide evidence regarding the relationships between level of education, as a measure of socioeconomic position, and health , and unemployment and health . The proportion of divorced people was higher than in the general population, which could indicate lower social support for PB beneficiaries, compared with the rest of the population [23, 24]. The beneficiaries were polymedicated and most were using medication for cardiovascular, mental and pain-related disorders, which would also explain the high use of drugs for acid related disorders, which are prescribed to prevent gastroduodenal side effects of polypharmacy and are generally overused . Female beneficiaries were more likely to use medicines for pain and mental related disorders than male beneficiaries, which could be related to a higher burden of chronic diseases in women .
The 12-month prevalence of use of psychotropic drugs (psycholeptics and psychoanaleptics) was high among PB beneficiaries (> 42%) and higher than that reported in Spanish primary care . Socioeconomic status, debt, workplace conditions and social capital are determinants of mental health [28–30]. This may partly explain the higher use of psychotropic drugs among PB beneficiaries, who were in a situation of economic hardship and more likely to be divorced than the general Catalan population. In addition, mental-health related stigma increases vulnerability to unemployment, especially in males and individuals with low levels of education . Thus, people with mental disorders may have experienced greater economic hardship than those without mental disorders following the economic crisis.
According to their profile of use of medicines and healthcare products, and in contrast to a typical primary care paediatric patient, the paediatric population of beneficiaries presented severe chronic conditions. Thus, this population presents the most complex paediatric cases (such as heart diseases, autoimmune diseases, conduct disorders and attention deficit hyperactivity disorder (ADHD)). The complexity of these chronic and mental diseases may increase the vulnerability of the family, which has to cover medical costs (such as medication and private specialized care) and other costs (home adaptations, informal care and educational accommodations) . In cases of economic hardship, children and adolescents are especially vulnerable . The high prevalence of use of these treatments among young beneficiaries could be explained by the greater prevalence of these disorders among disadvantaged populations  but also by the high costs of these treatments. This vulnerability may be even more pronounced when the minor is presenting with severe diseases. It is necessary to evaluate the coverage of care needs for the child, especially when careers are experiencing financial problems. This would be the case, for instance, for the approximately 30% of children and adolescents using psycholeptics and psychoanaleptics, usually indicated to treat conduct disorders and ADHD in the paediatric population.
More than half of NGO beneficiaries were taking medications for pain-related disorders and over a third were using opioids. Although there has been an increase in the use of opioids in Europe and the USA [35, 36], the prevalence of opioid use among PB beneficiaries is higher than that reported in previous studies. Similarly, the prevalence of use of other antiepileptics, which are also used to deal with pain-related disorders, was also high. Pain is highly disabling  and some opioids and antiepileptics, which are used in severe cases, are expensive. People with symptomatic and disabling disorders are more motivated to initiate a treatment , which could partially explain why they seek help to cover the treatment expenses when they are experiencing financial hardship. However, chronic pain is associated with high productivity losses due to sick leave and unemployment, partly due to comorbidity with mood disorders , which increases the vulnerability of people suffering from pain . Low-wage workers and those with worse working conditions are at higher risk of developing pain-related disorders and experience barriers to accessing quality care, which could hinder recovery [41, 42].
Cardiovascular disease and mental disorders are both chronic disabling conditions with serious clinical and economic consequences [43, 44]. Non-adherence to medication for cardiovascular disease and mental disorders worsens clinical status and increases the economic burden of these diseases [45–47]. The cost of medications is of potential importance in adherence to medications for these conditions  and the reduction of co-payment increases adherence to chronic medications, especially among the more vulnerable populations . A high proportion of the beneficiaries were using medication for the primary and secondary prevention of cardiovascular diseases and diabetes as well as medication for mental disorders. However, the cost of these treatments is low and some patients in need for these treatments may not reach the 20 Euros or more per month threshold set to claim benefit from the SMF. Therefore, there may be a number of patients with no access to these treatments that have not yet been identified.
Economic burden increases the risk of developing several physical and mental disorders, which, in turn, could increase economic hardship, aggravating the situation of the patients experiencing chronic diseases and economic problems. Although the welfare system should ensure access to medicines for patients with economic problems, 30% of the beneficiaries renewed the aid, which could indicate chronification of pharmaceutical poverty. In the future, studies should be carried out to assess the prevalence of chronification of pharmaceutical poverty and its impact on health.
Strengths and limitations
Interpretation of the results of this study should take the following limitations into account. First, the sample is comprised of people who seek help and fulfil PB criteria to benefit from the SMF. Therefore, the results cannot be extrapolated to all patients in a situation of pharmaceutical poverty, such as those with acute conditions, homeless people and illegal immigrants. Second, the information came from a small geographically restricted area where the SMF was available in 2018. As the aid is extended to other areas, deeper insight will be gained. Third, the study was based on patient registries and information on some key variables, such as comorbidities or social support, were missing.
In spite of these limitations, to the best of our knowledge, this is the first study to describe the pattern of use of medicines in a population affected by pharmaceutical poverty in a Western country. In this paper, we provide some clues about how morbidity patterns differ between the populations in situations of pharmaceutical poverty, which will be useful in better directing healthcare resources to vulnerable populations.