Polypharmacy ‘not hazardous’ in patients with multiple conditions, say GP researchers

Polypharmacy should not always be considered ‘hazardous’ as patients with multiple conditions may benefit from being on many different treatments, claim UK researchers.

Their study in primary care found the risk of having an unplanned hospital admission as a result of taking multiple medications was much smaller among patients with six or more long-term conditions, compared with those who had fewer conditions.

Only with the greatest level of polypharmacy did the risk rise substantially in multimorbid patients – among those taking 10 or more medications.

Scottish researchers said this may reflect more appropriate prescribing and management of patients with several long-term conditions compared with patients with only one or a few conditions, who may be less likely to receive care from the same GP and undergo regular reviews.

The study comes as GPs in England prepare to take on a directed enhanced service (DES) to prevent at-risk patients from unplanned hospital admissions.

The details of the DES are yet to be released, but the researchers urged policy makers not to rely on ‘crude’ measures of polypharmacy to identify patients at risk of an unplanned admission, and instead evaluate them in the ‘clinical context’ they were prescribed.

The study – published in the British Journal of Clinical Pharmacology this month – analysed data for over 180,000 adults with long-term conditions from 40 practices in the Scottish Practice Team Information project, to determine the drugs they were prescribed and linked this with hospital data on admissions in the following year.

For patients with just one long-term condition, the risk of having an unscheduled hospital admission was more than three times as high if the patient was taking 10 or more medications, compared with taking between one and three medications.

The risk of an unplanned admission was also increased slightly with use of four to six medications compared with one to three medications – by around 25%.

But the risks from polypharmacy were much lower in patients with six or more long-term conditions, among whom there was no increase in unplanned admission risk from taking four to six medications and a 50% increase from taking 10 or more drugs, compared with taking one to three medications.

Taking 10 or more medications was associated with more than three times the risk of having an unscheduled admission to hospital, compared with taking between one and three medications.

‘What is clear from our work is that the term “polypharmacy” should not be misinterpreted as a characteristic of care inevitably leading to adverse outcomes,’ the authors concluded.

Lead author Dr Rupert Payne, clinical lecturer in general practice at the University of Cambridge, told Pulse: ‘This piece of work demonstrates that using a crude measure such as polypharmacy is not really suitable and we need a more nuanced way of looking at risks from inappropriate prescribing.’

Dr Payne added that the findings could reflect more appropriate use of medications in people with several, related conditions receiving regular care from the same GP, as compared with less appropriate use among patients with a single or a small number of unrelated conditions, as a result of less consistent, joined-up care.

He explained: ‘Someone with multimorbidity is probably more likely to merit use of multiple medications, whereas a person with a single condition may not necessarily need those medicines, raising the question of whether the benefits are outweighed by an increase in adverse events or prescribing errors.

‘It may be a proportionately higher number of medicines relative to the number of things wrong with you reflects poorer care in general – for example, a lack of continuity of care, poorer communication between the GP and the patient, suboptimal medication reviews, or an inappropriate prescribing cascade, whereby more and more medications get added in to deal with problems resulting from other, previously prescribed pills.’

Dr Payne said targeting people for medication review on the basis of the number of their conditions as well as medications ‘would be impossibly complicated’ and said the proposed QOF indicator to conduct yearly medication reviews in elderly people on 10 or more medications, put forward by NICE for inclusion in 2015/2016, ‘is a pragmatic way of identifying those at the highest risk from [polypharmacy]’.

But he added: ‘The key thing is here is not that the review gets done – so it just ends up becoming a tick-box exercise – but for prescribers to be aware of when prescribing is inappropriate to have strategies for tackling that.’

Dr Martin Duerden, clinical adviser to the RCGP on prescribing and a part-time GP in Conwy, who co-authored a recent King’s Fund report into polypharmacy along with Dr Payne, said the finding that using multiple medications posed more risk to people with single rather than several comorbidities was ‘unexpected’ and supported appropriate use of polypharmacy.

Dr Duerden said: ‘One can speculate that people with a single disease who need an awful lot of treatment prove more difficult to keep stable. Presumably if medicines are chosen wisely and use optimised across a range of stable conditions polypharmacy does more good than harm, even in complex cases. This shows that polypharmacy can be worthwhile and is good news for prescribers and their patients.’

Br J Clin Pharm 2014; available online 15 January