Freelance medical writer, journalist and editor
Mark, a former research pharmacologist, now works as an award-winning freelance medical writer and journalist. He's also published numerous medical economic papers in peer-review journals and is the author of 10 books on health-related issues
NHS managers already struggle to contain spiralling expenditure on medicines and remain within their prescribing budget. The increasing demand for expensive therapies, exemplified by Herceptin (trastuzumab) for breast cancer and the increasingly acrimonious debate over the funding of Aricept (donepezil) and other cholinesterase inhibitors for Alzheimer's disease, increases the budgetary pressure.
Yet the NHS loses billions of pounds through avoidable adverse drug reactions (ADRs), wasted medication and not switching appropriate patients to the most cost-effective treatment.
Adverse drug reactions
Between 5% and 15% of patients develop ADRs.(1) Around 50% of these are moderate and around 14% are severe and may require further medical treatment.(2) Some ADRs are unavoidable: patients and clinicians trade the risks against the benefits. However, most ADRs are potentially avoidable and occur because, for example, the patient was inadequately monitored, the prescribed dose was inappropriate, the drug interacted with another medicine, or the patient did not comply with treatment.
In one analysis, these contributed to 67%, 51%, 26% and 33% of ADRs that lead to a hospital admission respectively (more than one factor may conspire to cause a serious ADR).(3) In such cases, managers can help by commissioning and implementing systems to ensure adequate monitoring, warn against drug–drug interactions, or highlight compliance issues.
Despite being common, there is a dearth of evidence quantifying the economic impact of preventable ADRs from the perspective of the NHS. However, in a paper published last year, I estimated that ADRs caused 392,000 acute admissions during 2003-4. The literature suggests that better medicine management could prevent 59% of these ADRs, equivalent to a potential saving of almost £369m.(2) The community consultation costs for ADRs reached £1bn. Assuming that medicine management could prevent 59% of these ADRs, the potential saving is almost £600m.(2) In other words, avoiding preventable ADR could potentially save around £1bn.
Poor compliance and medicine waste
Poor compliance is a common source of waste. Even the most clinically effective and well-tolerated drug will be useless unless patients take the medication. For example, patients need to take at least 75% of their statins to reduce the risk of cardiac events.(4) Furthermore, in patients with schizophrenia, noncompliance or intermittent use approximately doubles the risk of relapse.(5)
Unfortunately, noncompliance is common. For example, a recent paper examined adherence (another term for compliance) among patients with coronary artery disease who were prescribed angiotensin-converting enzyme (ACE) inhibitors, aspirin, ß-blockers and statins after cardiac catheterisation. Over the next year, 18% discontinued aspirin, 22% stopped taking ß-blockers, while the discontinuation rate for statins and ACE inhibitors/angiotensin receptor blockers reached 28% each. Many patients received more than one drug and just 54% adhered to all their medications.(6)
Noncompliance contributes to the massive wastage of medicine that drains scarce NHS resources. The Department of Health (DH) estimates that each year patients return medicines worth in the region of £100m unused to pharmacies.(7) But many more throw their unused medicines away. The DH also suggests that one in nine households have at least one prescribed medicine that the patient no longer uses.(7) Assuming that 16% of drugs are wasted, a typical literature value, the cost reaches £1.3bn annually in primary care alone.(2)
Over the years, numerous groups explored ways to improve adherence and reduce wastage. For example, the recent publication of consensus guidelines drew attention to the role of swallowing difficulties as a driver of waste and noncompliance.(8) Such problems are surprisingly common, although understudied.
However, in 2005, Ian Strachan and I reported the results of a survey performed in community pharmacies. Almost 60% of the patients over the age of 60 years reported difficulties in swallowing tablets or capsules. A similar proportion opened capsules or crushed tablets to make it easier to take the medicine. However, changing the formulation in this way can compromise efficacy or increase the risk of ADRs. Furthermore, relatively few of those questioned recalled their healthcare professional enquiring about whether they experienced difficultly swallowing. As swallowing problems can also indicate a serious condition, including some cancers,(9) managers should discuss making such questions a part of routine care, perhaps using electronic or paper-based reminders.
Managers could consider disseminating copies of the guideline to their clinical colleagues. The guidelines include an algorithm for the medication management of adults with swallowing disorders that could form part of a practice policy. Such policies should remind clinicians to avoid routine suggestions that the patient opened capsules or crushed tablets, unless the criteria outlined in the guidelines are met. Managers should remember that altering the formulation in this way might have legal implications, potentially placing a greater liability on the prescriber than when the medicine is used according to the marketing authorisation.(9)
Against this background, managers should also consider instigating a formulary review to ensure that clinicians can prescribe liquid formulations when appropriate. Liquid formulations are available in most therapeutic areas for patients unable to swallow medicines. Special-order manufacturers can make those not listed in the British National Formulary (BNF) or the Monthly Index of Medical Specialties (MIMS).(2) The guidelines suggest groups in which liquid and other alternative formulations may be appropriate,(9) which again could form the basis of a practice policy.
The acquisition cost of some liquid formulations is greater than the solid versions. Formal pharmacoeconomic studies need to compare solid and liquid formulations. However, in many cases, a relatively small "downstream" saving seems to offset the cost. For example, preventing a single day's admission to a psychiatric hospital would fund liquid chlorpromazine instead of the solid formulation for three patients for a year. Similarly, preventing a single admission for a major and minor infection would fund the additional cost of liquid metronidazole for approximately 121 and 53 patients respectively.(2)
Switching to cost-effective drugs
Managers should consider instigating systems to review regularly whether patients can switch to a cheaper medication without compromising care. For example, a recent analysis suggested that switching suitable patients from atorvastatin to generic simvastatin could save up to £1bn without compromising outcomes.(10)
Patients need to be carefully screened and not everyone can switch. For example, after reviewing 122 patients taking atorvastatin, the clinicians excluded 43 subjects. Seventy switched to simvastatin, but one switched back to atorvastatin after experiencing nocturnal visual symptoms. Four months after the switch, mean total cholesterol had not changed significantly. No adverse events attributable to the switch emerged.
They also reviewed 137 patients receiving the antihypertensive losartan and excluded 26 from switching to candesartan. Six patients didn't want to switch and seven switched back for a variety of reasons including chest tightness, patient request and anxiety about treatment.
The authors estimated that, including staff and administration costs, the practice saved £12,716 and £13,374 by switching statins and antihypertensives respectively. They suggest that savings will reach £14,713 and £14,009 respectively in future years. Indeed, over the next five years the practice would save £71,567. If the same proportion of patients switched across the primary care trust (PCT) and nationally, the savings would be £2.4m and £0.63bn respectively.
The study used relatively conservative switch criteria. The authors believe that a higher percentage of patients could switch, particularly if dosing regimens for those with chronic renal failure or potential interactions with other drugs were introduced. A 100% switch would translate into savings of £125,000, £4.2m and £1.1bn for the practice, the PCT and the UK, respectively.
No matter how much money is invested in the NHS, there will never be sufficient funds to do everything medically possible, for every possible patient. Indeed, budgets are already stretched to breaking point and, in a few cases, beyond. Yet as these examples illustrate, billions of pounds could be better invested or are simply wasted. No clinician, no politician, and no manager can afford to ignore savings on this scale.
Conflict of interest
The author received two educational grants from Rosemont Pharmaceuticals, one to perform the literature review and economic analysis, and one to analyse the survey of swallowing difficulties. This article is the author's sole responsibility.