Introduction: Problematic polypharmacy, where patients are prescribed multiple medications that are not therapeutically beneficial and can cause unnecessary and potentially harmful adverse drug reactions, can be mitigated using medication reviews. Polypharmacy can occur in patients with asthma taking multiple types of inhalers and medications for their asthma. They often have other medicated comorbidities, particularly those with difficult-to-treat or severe asthma. We have limited knowledge of the trajectory of polypharmacy management in patients with asthma. Therefore, it is imperative that we gain a better understanding of asthma polypharmacy management to control inappropriate polypharmacy given asthma’s association with polypharmacy and multimorbidities (where patients develop two or more co-morbidities concurrently). This study explored how existing polypharmacy management techniques may have impacted inappropriate polypharmacy generally and, specifically, in patients with asthma to provide a lens into how we might revise future medication management procedures, guidelines and resources in polypharmacy and asthma healthcare practice.
Methods: This mixed methods study included qualitative interviews focused on medication management processes and issues to provide a broader understanding of asthma polypharmacy that informed quantitative data analysis. The interviews were conducted to identify differences between general polypharmacy and asthma polypharmacy. Recruitment involved purposive and snowballing techniques to ensure a diverse population and reach saturation in responses. Two cohorts were questioned regarding polypharmacy treatment management and barriers involved in its implementation. The first focused upon healthcare professionals (HCP) (n=21) with a polypharmacy specialisation. Five GPs, four consultants and twelve general practice and hospital pharmacists were interviewed. The second study focused on asthma HCPs (n=32). Eight GPs, eight asthma specialist consultants, nine pharmacists and seven nurses were interviewed. To determine the extent to which the interviews captured wider clinical practice, quantitative analysis explored pattern changes in a retrospective longitudinal data set containing Scottish asthma patient records (n = 671,238; 51.12% women) from 2009 to 2017 using R studio. The data was stratified by multimorbidity, age, socioeconomic background and gender. Differences in deprescribing and hospital admissions due to adverse drug reactions were also analysed.
Results: The GPs interviewed noted that, in general polypharmacy, structured medication reviews occurred less frequently than informal medication reviews, due to time constraints. However, amongst patients with asthma, asthma annual reviews were strongly adhered to and contained a medication review though polypharmacy was not a specific focus. HCPs noted that roles and the allocation of responsibilities when conducting medication reviews, repeat prescription monitoring and deprescribing in primary and secondary care were not well-defined, reflecting confusion about which HCPs were charged with these ‘responsibilities’. Specialist nurses in asthma and pharmacists felt less confident than physicians in removing medications lest their patients’ symptoms or illness returned and preferred lowering dosages instead by stepwise deprescribing as noted in asthma guidelines for inhaled and oral steroids. Interprofessional communication between primary and secondary care was very limited, particularly regarding patient medication changes. The dataset analysis revealed that the onset of asthma polypharmacy typically occurred at 50-59 years of age but arose at a younger age (40-49) amongst those from lower socioeconomic backgrounds, especially men. Polypharmacy also coincided with increased levels of multimorbidity. These patterns were also identified by HCPs in the interviews. Since 2012, polypharmacy has steadily decreased and deprescribing gradually increased – coinciding with the introduction of the Scottish Polypharmacy Guidance, which offers detailed advice on conducting medication reviews and deprescribing. Stepping down medication was found to be more prevalent than outright removal, (also confirmed in the interviews). Patients taking 15+ medications had the highest levels of hospital admissions across all patients over the age of 50, particularly between ages 70 and 90, possibly due to increased frailty. Though overall prescribing/deprescribing patterns broadly followed Tudor Hart’s inverse care law, whereby, access to care by different social demographics is inversely promotional to need, deprescribing of medications over time observed in the 5-9 medication category was irrespective of social class, age and/or gender. The widely observed differential access to care flagged by Tudor Hart appeared to be eroded by the increased engagement of older frail patients across the board (regardless of demographic) with healthcare services.
Conclusion: Current polypharmacy policies target frail over-75s with polypharmacy. Polypharmacy seemingly decreased amongst this demographic suggesting that their increased engagement with health services due to their frailty increases their opportunities to have a medication review. However, polypharmacy is often experienced by those significantly younger than 75, particularly, we have shown, amongst younger multimorbid patients from lower socioeconomic backgrounds (especially men). This, the study suggests, may be because of their lower engagement with healthcare services. Targeting demographics with less interaction with healthcare services could advance polypharmacy mitigation/management. The potentially low levels of deprescribing observed confirms HCP acknowledgement that structured medication reviews are occurring less frequently and systematically than suggested by policy (though they occur under certain contingencies such as the asthma annual review). The continuing high level of hospital admissions amongst patients prescribed 10+ medications calls into question the adequacy of medication reviews performed for atrisk patients requiring polypharmacy management. Clarifying the function and roles associated with medication reviews across care systems could enhance the discovery of inappropriate polypharmacy in patients and prevent unnecessary drug related hospital admissions. Undertaking mixed methods analysis, involving both detailed qualitative interviews and large-scale quantitative modelling, presents challenges to the researcher in terms of both the scale of research work and the range of tools and skills that need to be deployed. It does, however, offer important additional insights – particularly in this case the opportunity to link HCP perceptions about care processes with more general modelling of patient morbidity patterns and engagement with health services that are not necessarily apparent to respondents involved.
