Twenty-first century medicine is witnessing an unprecedented paradox. On the one hand, achievements of modern medicine and pharmacy, along with a boost in global economy, led to a new scenario offering billions of human beings access to medications they need. On the other hand, multiple medicines used by a lot of individuals not only add to the spiral rise of healthcare costs but also entail additional risks. Thus, a positive concept of ‘access to drugs in case of need’ is slowly evolving into an unfavourable phenomenon of “polypharmacy”, which becomes a chronic problem, particularly among the elderly and constitutes one of the major concerns of the public health worldwide.

Polypharmacy lacks a standard consensual definition. Nevertheless, its paradoxical nature is reflected in terminology. In general, polypharmacy describes a scenario in which multiple medicines are used by the same patient. In practical terms, polypharmacy is most often defined as a concurrent use of five or more drugs, whereas the use of ten or more drugs is usually regarded as ‘excessive polypharmacy’ (World Health Organization, 2019). However, these numbers are used for pragmatic reasons only as there is no firm evidence based on which a sound threshold could be created, dichotomizing the number of drugs used concurrently to be either acceptable or too high (Masnoon et al., 2017).

Risks associated with polypharmacy are multiple and include potentially inappropriate prescribing, adverse drug reactions, drug-drug interactions and decreased adherence to medication, which all lead to further negative health consequences, such as reduced quality of life, negative health outcomes and increased healthcare services utilisation (Khezrian et al., 2020; Lee et al., 2020). The longer the exposure to polypharmacy is, the more probable and more pronounced all of these negative consequences are.

The significance of the challenge created by polypharmacy has been increasing, especially due to its escalating prevalence. Particularly in Europe, recent years have seen a growing trend for this phenomenon, e.g., in Sweden the prevalence of polypharmacy increased between 2006 and 2014, from 16.9 to 19.0% (Zhang et al., 2020).

While polypharmacy might be temporal among younger patients (e.g. due to infection), it is usually chronic in the elderly. The possibility of long-term multidrug therapies increases with age and related multimorbidity. These interlinked factors are undoubtedly the major drivers of the recent rise in polypharmacy prevalence in Europe. Data collected in the UK showed that 20.8% of patients with two clinical conditions were prescribed four to nine medicines, whereas in those with six or more comorbidities, the relevant percentage was 47.7%. At the same time, statistics show that more than 50% of people aged over 65 years are diagnosed with two or more diseases, and the older they get, the more diseases they suffer from (Barnett et al., 2012).

Therefore it should come as no surprise that the problem of polypharmacy in elderly people is already widespread in Europe. A nationwide cohort study conducted in Sweden among individuals aged ≥65 years found prevalence of polypharmacy in 44.0% of the group, and the prevalence of excessive polypharmacy in 11.7% (Morin et al., 2018). In this country, the existence of these scenarios strictly correlates with age and peaks up to 79.6 and 36.4% in individuals aged 90 years and over, respectively (Zhang et al., 2020). Scottish data provide evidence that around 35% of those aged 85 years and over receive more than ten medicines (Stewart et al., 2017). A recent analysis of a large European cohort found polypharmacy to occur in 32.1% of citizens aged 65 years or above, ranging from 26.3 to 39.9% across 18 of the studied countries (Midão et al., 2018).

The observed rise in polypharmacy prevalence is particularly pronounced in the elderly (Hovstadius et al., 2010). Over the period of 15 years, the prevalence of polypharmacy in this group of patients grew fourfold in Ireland, from 17.8 to 60.4% (Moriarty et al., 2015). Currently those aged over 65 years account for 19.2% of the European Union population, and this proportion is expected to reach 29.1% by 2080, whereas in the case of those aged over 80 years, relevant percentage rates will change from the present 5.4–12.7% (Eurostat, 2020). If these predictions prove to be true, the burden of polypharmacy is expected to rise dramatically in Europe in the upcoming decades.

In Poland, neither prevalence nor characteristics of polypharmacy have been studied extensively so far. Nevertheless, there are good arguments to believe that its significance might particularly result from high use of prescription medications in the country. In the European health interview survey (EHIS), the collected data indicated a slightly higher use of such medications in Poland, as compared to the EU-28. That tendency, however, was particularly pronounced in the elderly–use of prescription medications was reported by 83.6% of those aged 65–74 years, and 92.8% of those aged 75 years and over in Poland, whereas the European average in these groups was 78.1%, and 87.1%, respectively (Eurostat, 2021). Moreover, a very high prevalence of polypharmacy (78.6%) was observed among Polish patients provided with palliative care (Grądalski, 2019).

Moreover, the Polish population is ageing fast (Leszko et al., 2015). Consequently, polypharmacy has become a serious medical, social and economic threat, exerting a major impact on the sustainability of the national healthcare system. From this perspective, an objective assessment of polypharmacy rates in elderly citizens is of utmost importance for the national health policy. What is of particular interest, however, is the identification of the most vulnerable group of patients being at high risk of chronic polypharmacy.

The aim of our study was to estimate the prevalence of chronic polypharmacy in the elderly (65+) population in Poland, using databases of the National Health Fund (NHF, Polish: Narodowy Fundusz Zdrowia). NHF is the sole public payer organization in the Polish healthcare system with a nationwide coverage. The NHF databases collect information on dispensation of reimbursed drugs, as well as on utilization of healthcare services. Based on an analysis of the data, we wanted to characterise the subgroup of elderly patients with the highest risk of chronic polypharmacy.

To the best of the authors’ knowledge, this is the first study to describe chronic polypharmacy in Polish elderly people. It provides detailed characteristics of the subgroup of patients who are most likely to be affected by this phenomenon. Our findings show that chronic polypharmacy is a frequent problem among Polish older adults. On average, over 40% of Polish elderly citizens were on polypharmacy in 2018, and every fifth was on chronic polypharmacy. Considering the fact that the population of Poland is aging fast, and the number of elderly citizens is continuously rising, these findings are crucial for the national health policy, and definitely, deserve a lot of attention.

Despite diverse definitions of polypharmacy and methodologies employed in individual studies, recent European data are also alarming when it comes to the prevalence of polypharmacy in the elderly. In the last years, the prevalence of this phenomenon among older people has risen even further in Europe (Carmona-Torres et al., 2018). Polypharmacy was observed in 21.9% of community-dwelling Spanish elderly people (Carmona-Torres et al., 2018), 39.4% of Italian elderly citizens (Slabaugh et al., 2010), 41.2% of Swiss older adults (Blozik et al., 2013), and 51% of Danish individuals aged over 75 years (Kornholt and Christensen, 2020). Based on the data collected in the Sixth Wave of SHARE survey, completed in November 2015, polypharmacy was identified in 32.1% of elderly Europeans, on average, whereas in Poland, this ratio was higher and amounted to approximately 33.8% (Midão et al., 2018).

Due to its natural background related to multimorbidity which is usually composed of chronic diseases, polypharmacy in older age is in most cases a chronic condition (Muth et al., 2019). This, however, does not mean that its long-term nature is well-studied. One of the few exceptions is a longitudinal nationwide cohort study including all older Swedish adults (aged 65 years and over) with five or more prescription drugs in October 2010. The proportion of individuals who remained exposed to polypharmacy after 6 months, 12 months and until the end of this over 3-years-long study was 82, 74 and 55%, respectively (Wastesson et al., 2019). Our own observations of two thirds of chronic polypharmacy patients who maintain this status for the period of the whole year suggests that once an elderly person is prescribed a high number of drugs, the chances for reducing this number are very low. Another study covered an even longer period of 10 years (between 2000 and 2010) and analysed data of nearly two million patients aged 65–94 years living in Lombardy (Northern Italy). The overall prevalence of chronic polypharmacy, defined as administration of five or more drugs during 1 month for at least six (consecutive or not) months in a year, rose from 1.33% in 2000 to 3.34% in 2005 and 7.10% in 2010 (Franchi et al., 2013). In a Dutch study which included 45,731 patients aged 55 years or over with at least one prescribed medication, 27% were found to experience polypharmacy. The number of medications used in the polypharmacy group was on average 11.2 of which 6.9 was used chronically (Sinnige et al., 2016).

Our findings indicate that with similar absolute numbers, chronic polypharmacy was much more prevalent in Polish elderly men than in women. This is an unexpected result as in the studies performed in other countries, polypharmacy in the elderly was found to be associated with female gender. Other known drivers of polypharmacy in the elderly include age, being separated/divorced/widowed, lack of education, higher body mass index, being bedridden and self-medication (Carmona-Torres et al., 2018). Factors associated with chronic polypharmacy involve similar characteristics, i.e., a more advanced age, female sex, living in an institution, chronic multimorbidity and multidose dispensing (Wastesson et al., 2019).

Among the factors contributing to polypharmacy, age is a particularly important one as polypharmacy prevalence rises dramatically with years of life. A clear example of such a correlation are the results of a nationwide Swedish study. Among those aged <60, 60–69, 70–79, 80–89 and over 90 years, polypharmacy was present in 8.5, 35.9, 54.8, 73.0 and 79.6%, respectively, with excessive polypharmacy peaking up to 36.4% in individuals aged 90 years and over (Zhang et al., 2020). Our observation of a mean age of 76 years among elderly patients on chronic polypharmacy in Poland corresponds well with this tendency.

A marked variation in geographical distribution of chronic polypharmacy among Polish elderly citizens was also an interesting finding of our analysis. No matter which administrative unit of the country is considered, Łódź appears to be the epicentre of chronic polypharmacy. There are other data proving that the health parameters in this region deviate negatively from national averages (World Health Organization, 2012). Perhaps the variation of polypharmacy prevalence in the elderly is not only a Polish specificity since similar findings were reported in Italy and the Netherlands (Franchi et al., 2013; Sinnige et al., 2016). Nevertheless, uneven distribution of chronic polypharmacy density across various regions should be taken into account when drawing up regional health plans.

Elderly patients on chronic polypharmacy characterised in our analysis were provided with care by multiple health professionals. This is certainly a reflection of their poor health and the need to obtain necessary health service. Nevertheless, these findings also indirectly point to a lack of coordinated care and imperfect communication between various prescribers and healthcare institutions, which leads to chronic polypharmacy in the elderly. So far, only several health conditions (e.g., myocardial infarction) have been covered by coordinated care in Poland, and when it comes to communication, the major innovative enabler ensuring it, i.e., the nationwide electronic health record, has not been fully introduced yet. Fortunately, both these solutions are included in short-term development plans of the National Health Fund and the Polish Ministry of Health. Therefore, it may be expected that this situation will change for better.

Not surprisingly, our cohort of the elderly people on chronic polypharmacy was found to be hospitalised twice more often than the general Polish population of citizens aged 65 years or over. Perhaps this correlation between polypharmacy and hospitalisations in elderly patients is not surprising as those with poorer health may not only need more drugs but also more frequent hospitalisations. However, it seems that hospitalisation is an independent risk factor for polypharmacy in general, and inappropriate polypharmacy in particular. In an Irish study conducted among older people admitted to hospital, the likelihood of potentially inappropriate prescriptions after admission was higher than prior to it (adjusted odds ratio 1.72), regardless of patients' characteristics (Pérez et al., 2018).

A specific local factor that may certainly have an impact on the rate of polypharmacy in Polish elderly people is the availability of basic drugs free of charge offered to this group of citizens. Starting from September 1, 2016, “Program Leki 75+” (“Drugs 75+ Program”) was initiated. It enabled those aged 75 years and above to obtain these drugs at no co-payment. The overall idea of the program was to ensure access to necessary medications to those at the highest risk of multimorbidity since, in general, the prescribed drugs are subject to co-payment by patients in Poland, which varies both across and within specific drug classes. This, however, might be an incentive to overprescribe both for prescribers and their patients rather than to look for other non-pharmacological options of addressing health problems. So far, this problem has not been extensively studied and dedicated research is required.

Finally, it needs to be emphasized that the analysed medicines that contribute to chronic polypharmacy are the drugs used typically for management of chronic conditions. Among the top five ones, four were indicated for lifelong treatment, i.e., 1. Metformin (mostly recommended for diabetes), 2. Atorvastatin (hyperlipidaemia, coronary artery disease), 4. Ramipril (hypertension, chronic heart failure and other cardiovascular conditions), and 5. Amlodipine (hypertension and other cardiovascular conditions). This list, undoubtedly grouping highly indicated drugs, differs considerably from the one including the most prevalent potentially inappropriate ATC codes identified in the Swiss elderly, of which the top five were Zolpidem, Estradiol, Acemetacin, Amiodarone and Trimipramine (Blozik et al., 2013). Thus, it might not be an easy task to discontinue such treatments in elderly patients in Poland without causing a serious disruption of their care.

Our findings also deserve practical solutions. A recent WHO report on polypharmacy urges countries to put polypharmacy high on their agendas in order to reduce its prevalence by implementing dedicated programs (World Health Organization, 2019). Quite often, however, it is still not the case in Europe. A search for polypharmacy management programs, undertaken within the framework of the SIMPATHY project, revealed such initiatives in five out of nine assessed countries only (McIntosh et al., 2018). Regrettably, no such official program was identified in Poland (Stewart et al., 2017), nor introduced to the date of this publication.

To be safe, effective and cost-effective, any program that attempts to deal with the complexities of prescribing medications in elderly people should be patient-centred, clinically robust, multidisciplinary and designed to fit into the healthcare system in which it is delivered (Stewart et al., 2017). Such a program may be based on one or multiple interventions. So far, various solutions have been proposed to reduce inappropriate prescribing and subsequent polypharmacy in older adults, ranging from comprehensive geriatric assessment, shared decision-making, medication reviews performed by either pharmacists or physicians, training of healthcare staff, use of various guidelines, checklists, up to different forms of computer and/or artificial intelligence-assisted clinical decision support systems (Lee et al., 2020).

Comprehensive approaches work well, e.g., dedicated palliative consultations resulted in a decrease in the number of drugs used in complex palliative patients in Poland (Grądalski, 2019). However, they also impose serious limitations related to their time-consuming nature, as well as a need for highly experienced staff. Unfortunately, with a very limited number of practicing geriatricians and absence of clinical pharmacists working in outpatient care, scaling up of such results has not been possible in Poland so far.

Considering the above, it seems to be much more realistic to implement simpler, explicit criteria-based interventions aimed at deprescribing, such as drug reviews using validated tools (e.g. STOPP/START or Beers criteria) (Kurczewska-Michalak et al., 2021). Such interventions may be further developed by dedicated applications or computer-assisted decision support systems, in order to promote their applicability. However, these approaches are still time-consuming, which makes their implementation a considerable challenge for busy clinicians who sometimes, unfortunately, do not pay much attention to the problem of polypharmacy.

In such circumstances, it may be expected that another intervention to be introduced soon will help prevention and management of polypharmacy in elderly patients in Poland. The Polish Act on the Profession of Pharmacists (Dziennik Ustaw, 2021) became effective in april 2021. Among innovations codified by this Act, there is a new service provided within pharmaceutical care which was not available in Poland before. Under the ministerial document specifying the scope of the service, it will cover identification, management and prevention of drug problems in general, and it will also include reviews of drugs which will most probably be reimbursed (Ministerstwo Zdrowia, 2021). Thus, access to professional drug reviews may be soon widely available in Poland, with obvious benefits for elderly people facing the risk of inappropriate polypharmacy.

This study has several limitations. One of them is that we were not able to correlate an individual exposure to polypharmacy with either the kind or number of conditions that an individual patient was diagnosed with. Similarly, we could not assess whether the identified cases met the criteria for either ‘appropriate’ or “inappropriate polypharmacy”. All that was not possible due to the fact that the nationwide electronic health record system has not yet been launched in Poland, which made comparisons between clinical and dispensation data very difficult and limited them to the reports on hospital stays or some outpatient services. Thus, we could only hypothesize that multimorbidity must have had an effect on polypharmacy prevalence in the studied population. There exists evidence proving that the greater the number of conditions an elderly patient is diagnosed with, the higher the probability of polypharmacy (Slabaugh et al., 2010).

Another limitation of our study is related to the scope of the analysed drugs which was narrowed down to reimbursed prescription medications only. In fact, polypharmacy is a problem that may be caused by various sorts of remedies, including non-reimbursed prescription drugs, as well as over-the-counter (OTC) drugs and dietary supplements which are often overused in Poland (Bochenek et al., 2016). Thus, our findings should be accepted as conservative estimates. A survey-based study assessing older (70+) primary care patients in Germany found that 26.7% of them were on prescribed polypharmacy, however, the percentage increased to 53.6% when OTC drugs were included as well (Junius-Walker Uet al, 2007). On the other hand, this is a natural disadvantage of analyses based on pharmacy claims data since they do not capture dispensation of OTC drugs or drug-similar products. However, the alternative approach, which is based on surveying and thus makes it possible to identify the use of non-prescription products, is subject to a large recall bias, and considerable underreporting.

Finally, our analysis covered only 1 year. In order to better understand the prevalence of polypharmacy in the elderly, and in particular, to observe its dynamics over time, the longitudinal analyses are warranted.

Nevertheless, this study has also a number of strengths. It was based on a nationwide database, with only a few drug groups of minor importance excluded from the analysis for practical reasons. Moreover, our analysis was based on dispensation, and not prescription data, which allowed us to avoid a considerable bias. Due to various reasons, a large number of prescriptions is never filled. We found this proportion to reach as many as 20.8% of all prescriptions issued in Poland (Kardas et al., 2020).

This study was the first of this kind involving a nationwide assessment of chronic polypharmacy in Polish elderly people. We found that this problem affected one fifth of Polish older adults and it remains stable due to its direct relation to chronic conditions. We also observed a marked variation in geographical distribution of chronic polypharmacy in Polish elderly citizens, peaking in the Łódź Voivodeship. The medicines that contributed most to chronic polypharmacy in our analysis were the drugs used typically for management of chronic conditions. It is noteworthy, however, that our analysis did not cover OTC drugs which could impact polypharmacy even more. Considering the fact that the population of Poland is aging fast, and the number of elderly citizens is continuously increasing, one may expect a further rise in chronic polypharmacy among Polish elderly citizens in the upcoming decades. Therefore, our results confirm that this phenomenon is highly important for the national health policy and requires relevant interventions. The planned introduction of pharmaceutical care in Poland may be expected to provide a practical solution that will help to address this problem properly.