Interventions that address unintentional non-adherence seek to reduce barriers and improve the patient’s ability to take medicines as prescribed. A wide range of strategies has been studied.
Cost
Out-of-pocket cost is a well-recognised barrier to accessing medicines.16 In a recent survey, the Australian Bureau of Statistics reported that 7.6% of patients who had received a prescription delayed getting the medicine, or did not get it at all, due to cost. The proportion was even higher in areas of disadvantage.17 Prescribers may be able to reduce the impact of cost by, for example, prescribing generic or lower cost medicines when appropriate. Pharmacists may also assist patients by recommending lower cost brands.
Drug regimen
Patients can be confused by the number and variety of medicines they need to take. Adherence has long been known to be inversely associated with the complexity of the regimen.18 Prescribers should aim to simplify this as much as possible. Discussion with a pharmacist may assist, particularly with tailoring appropriate preparations, formulations and packaging for the individual (e.g. people with an inability to swallow).19 These consultations may be rebatable in Australia using the Medicare medication management review items. It may be possible to reduce the frequency of administration, introduce combination medicines, or even deprescribe in some instances.20
It is good practice to provide patients with a printed list of their medicines and the times of day when they should be administered. Alternatively, the patient may be encouraged to use a smartphone app such as the NPS MedicineWise MedicineList+. The patient’s understanding of their regimen should be checked. For patients with cognitive impairment, the support of a carer to encourage or assist with administration is essential.
Brand swapping when medicines are dispensed may cause confusion and impair adherence. Pharmacists have a responsibility to educate patients if they swap brands, and prescribers should explain to patients and carers when they may be offered a choice.
Fixed-dose combinations can be helpful for patients on multiple medicines, and have been shown to improve adherence in some circumstances.21 Starting treatment with combination medicines has a strong evidence base in the management of HIV and other infections. For conditions such as hypertension, the evidence for starting with more than one medicine is mixed, but the strategy should be considered.22
Patient reminders
Reminder packaging, which incorporates a date or time for a medicine to be taken, is an effective way of promoting adherence and has been shown to improve biological outcomes in type 2 diabetes and hypertension.23 Drug administration aids are a form of reminder packaging and may be particularly helpful for patients prescribed multiple medicines. However, they are not suitable in all circumstances.24 The stability of some drugs may be compromised by repackaging.25 Patients with impaired cognition, eyesight or dexterity often have difficulty using them. Repackaging by the pharmacist may increase the cost to the patient and filling a compartmentalised box at home can lead to errors. Also, such boxes are rarely childproof.26
There is strong evidence that regular reminders are an effective strategy for increasing adherence.27 Electronic devices can assist with this. In a randomised controlled trial, 143 adults with asthma used combination fluticasone propionate/salmeterol inhalers with attached electronic monitoring devices. The device recorded inhaler activation and provided twice-daily reminders for missed doses to those in the intervention group. Over six months, adherence was over 50% higher in the intervention group than in the control group.28
A meta-analysis evaluating the use of text messaging in adults with chronic disease found it doubled the odds of adherence across 16 randomised controlled trials. The effect was not dependent on message characteristics such as personalisation, two-way communication or daily frequency.29
As new information and communication technologies develop, new strategies for promoting and monitoring adherence are emerging. An example is ‘smart pills’ which send a signal to an external monitor when a tablet has been ingested. The signal can be linked to automated adherence reminders and to a medication reconciliation system.30