Whether or not patients actually take the medicines they have been prescribed in hospital has been the focus of research with patients throughout the period covered in this review. Twenty four studies attempted to measure patients’
adherence, compliance or persistence with intended long-term medicines within three months of hospital discharge. The terms persistence and adherence have been defined as two different constructs:175 a patient is adherent if prescribed medicine instructions are followed, whilst persistence is characterised as
continuing treatment for a prescribed period. Continuity of treatment in a further seven studies is explored as the extent to which discharge medicines continue to be prescribed by the patient’s GP. Continuity is considered alongside
medicines discrepancies, which are defined as differences between what was prescribed at discharge and the medicines the patient actually takes.
Discrepancies were measured in two studies, both using the USA medicines discrepancy tool (MDT).58
Adherence and persistence
In studies dating from 1992–2014 measures of adherence and persistence were taken at varying time-points from 48 hours after discharge up to the three-month post-discharge cut-off point for this review. Justification was rarely made for the timing of the patient follow-up. Rates of adherence were documented to be as high as 100% for stroke patients taking diabetic medicines;176 and as low as 6.5% in USA medical-surgical patients.177 In some cases sample sizes were very small, limiting predictive value;177,178 and only seven of the studies were
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conducted with patients discharged from multiple hospital sites. Reported adherence and persistence rates from each of the studies are detailed in Table 6 on page 68.
Measures of persistence
Three studies measured persistence, defined as “continuing a therapy or class of therapy from discharge to the 3-month follow-up;179(p1457) Each of these studies also explored if non-persistent patients had self-discontinued or if they had discontinued with the knowledge of an HCP.179–181 One of the larger studies measured persistence with stroke prevention medicine after discharge amongst USA patients (n=2,598).179 Regimen persistence comprised taking all classes of medicines and composite persistence was calculated as the percentage of medicines classes patients were still taking. The sample was 95.5% persistent with all medicines prescribed at discharge. A year earlier, persistence with evidence-based medicines for USA patients with acute coronary syndromes (n=1107) was recorded three months after discharge.181 They found patients to be less persistent (71.8%) and in 61.5% of those cases the patient had decided to self-discontinue. Persistence was associated with fewer types of medicines classes, increasing age, medical history, less stroke disability, insurance, working status, knowledge of medicines, increased quality of life, hardship, region and hospital size.179
Measures of adherence
The studies identified used varying definitions of adherence and different measurement techniques or measurement scales, such as the Medication Adherence Report Scale (MARS),182 and the Adherence to Refills and Medications Scale (ARMS).183 Some studies measured rates of
under-adherence, over-adherence and overall under-adherence, whilst others characterised patients as fully and partially adherent. Differences between adherent and non-adherent patients were reported as: being older (more non-adherent), having a greater perceived risk of not adhering, personal susceptibility to disease, satisfaction with previous treatment, cognitive memory failures, and patients’
subjective value of health;184 better self-reported health status and higher number of medicines predicted non-adherence in a study of Swedish
patients;185 adherence levels between patients on a higher number of medicines
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were different in elderly Italian patients on polypharmacy;186 whilst belief in the necessity of medicines significantly predicted adherence in a further study conducted in the Netherlands.187 Amongst schizophrenic patients being non-compliant was associated with risk of readmission, accessing emergency care, being homeless and experiencing worsening symptoms;172 there was also an association with family refusal to be involved in treatment and non-compliance.
Compliance was associated with drug misuse and recognising symptoms.
Mansur et al. (2009) found an association between non-adherence to at least one medicine and inappropriate prescription drugs prescribed at discharge,188 although a more interesting finding in their research is that nearly half of the elderly patients (45%), were discharged with at least one inappropriate prescription medicine.
Exploring adherence qualitatively
In the UK, adherence to medicines following a stent procedure was explored qualitatively with 20 patients. They reported good relationships with GPs to be an influencing factor, along with understanding of the purpose of medicines and their health condition, having a medicines routine and perceiving positive
benefits to taking medicines. Some patients were unclear about the community pharmacy role in supporting adherence, although patients were interviewed within a week of discharge so would not have had an opportunity to experience a post-discharge MUR or collect a repeat prescription.163 A sample of Australian patients found it difficult to adhere to new medicines because the new
medicines altered their routine.167 Patient discontinuation of clopidogrel was explored in two comparative USA studies by a Kansas-based team.147,148 They compared those patients discontinuing (stopping completely) clopidogrel with continuers;147 and patient and clinician views on reasons for discontinuation,148 however the clinicians interviewed were not involved in the care of the patients, which limits the value of the comparison. Both studies found that system-related factors, such as poor communication and gaps in care transitions, contributed to patients stopping taking their medicines. These studies are included in Table 5 (previously referenced on page 41).
Medicines discrepancies and continuity of treatment
A range of studies looked at discrepancies in medicines use and the continuity of patients’ medicines in the period following their discharge. Studies used
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primarily quantitative methods to generate evidence about the stability of
patients’ medicines use after leaving hospital. They are presented in Table 7 on page 73.
Discrepancies were identified in hospital medical records and patient reports of medicines for elderly US patients (n=80): congruence was found in only six of these patients and patients reported taking significantly more medicines than recorded in hospital records (p=0.001).139 A Swedish study using structured interviews one week after discharge, again with elderly people, identified 30% of patients to be using their medicines as documented in their medical record, which included changes made by their primary care team after their hospital stay.189 Discrepancies in medicines were also reported qualitatively by discharged patients from non-English speaking backgrounds in Australia.167 A Medication Discrepancy Tool (MDT) constructed for use with elderly patients attempted to assess the prevalence and predicting factors of post-discharge medicines discrepancies.95 In this US study (n=375) based on one site with patients with different health conditions, 14.1% experienced one or more discrepancies and patients with discrepancies were on average taking
significantly more medicines. Discrepancies were attributed either to the patient or to the system. Non-intentional, non-adherence was the most common
discrepancy associated with the patient, whilst poor quality discharge
information was the most common system discrepancy. Those patients taking more medicines (OR 1.13, CI 1.04-1.23) and those with congestive heart failure (OR 2.1, CI 1.09-4.03) were more likely to experience discrepancies. Rates of readmission within 30 days were also significantly higher for those patients with discrepancies (14.3%) than for those with no discrepancies (6.1%).
Understanding the causes of discrepancies can reveal failures in the system, yet they fail to show how system-level and patient-level factors interact, for example, how poor quality discharge information or conflicting information may directly lead to non-adherence. They also fail to take into account individual variation in care interactions, for example, the nature of the network of
professionals surrounding the patient. The MDT was later used in another USA study with 103 elderly patients.39 Over half the sample (52%) had discrepancies about one week after discharge, and an association was found between
cognitive impairment and higher rates of discrepancy, as well as with lower
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levels of medicines knowledge. A different USA study found that 56% of patients had medicines discrepancies two days after discharge. In this study taking medicines not listed on the discharge summary and not taking listed medicines were categorised as discrepancies as well as taking medicines incorrectly. The authors assessed the most common cause to be inaccurate discharge instructions, followed by intentional non-adherence.190 They found that those patients with inadequate or marginal health literacy were more likely to unintentionally be non-adherent.
A Danish study (n=200) also found wide-ranging incongruence between discharge medicines lists and patient medicines use a few days after discharge.140 Reconciliation errors and poor communication were the main cause of incongruence. Continuity of treatment was explored by a number of studies throughout the 1990s through to 2012.39,161,173,174,191–193 The largest, conducted in Australia, combined in-patient medical record review, a GP survey, and a patient telephone survey three months after discharge for 1319 patients from 49 hospitals after a heart attack.193 It found a significant decrease in prescriptions of antiplatelets, statins and beta-blockers, and all four
recommended medicines in combination (which include ACE inhibitors / (AII)-antagonists). Patients reported that GPs had stopped 44% of these medicines.
The prescription of all four guideline-recommended medications was greater in male and younger patients. Little detail is offered about the structure of the questions patients were asked and whether they referred to any written information on their medicines during the survey.
Eijsbroek et al. reported on the continuity of medicines focussing on intensive care unit (ICU) admission, ICU discharge and hospital discharge for 21
patients.150 They reported that 107 medicines were prescribed regularly before ICU admission, 150 were prescribed on ICU discharge, 121 at hospital
discharge, and 108 three months later. Eight (5.3%) chronic medicines were discontinued on the ICU and not restarted on discharge (mainly diabetic medicines). The authors did not report on any documented reasons why medicines had been stopped. Other assessments of medicines continuity
explored the experiences of elderly patients using structured questionnaires and home visits.161,173,174,192 A small study (n=56) of UK elderly patients attempted to assess the extent of prescription continuity.174 They found 63% of prescriptions
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were unaltered by the GP after discharge; however this figure only includes additions and omissions and not changes in dose, direction and name. 27% of patients had not received a new supply of medicines and nearly half (48%) had old supplies of medicines at home. In the same year another small study found that amongst 50 UK patients 45 were taking different medicines 6–14 days after their discharge.173 Changes included the name of the medicine (20 patients), new medicines (20), stopped medicines (10), changed directions (11) and altered doses (11). In the Mansur et al. study of 198 elderly patients one month after discharge, 16% had no changes to their medicines one month after
discharge.192 Patients who visited their GP only one time in the month after discharge had significantly fewer changes than those who visited more times or didn’t visit at all (p < 0.05). Half of all changes were an addition of a medicine or an increased dose, over a quarter (26%) were discontinuing, 16% omitting it, and 8% switching it for an alternative. The majority of changes (70%) were due to recommendations by specialists or a change in the patients’ health, the remainder were mostly due to adverse effects, poor adherence by the patient and administrative reasons. Patients who were non-adherent to at least one drug had significantly more changes to their medicines than those who were adherent.
A study of the effectiveness of the system of medicines management for
discharged elderly patients conducted in the late 1990s (n=68) found more than half of patients experienced problems with their medicines, which were
assessed to be due to actions or omissions of HCPs, such as incorrect drugs, doses and drug combinations being prescribed in primary care, and patients purchasing unsuitable over the counter medicines.166 This study is noteworthy as it examines system-related problems in UK healthcare in advance of more well-known work applying systems thinking in the healthcare and medicines context.63,194 That it was conducted on only one site limits generalisablity and its age restricts its relevance to current healthcare systems.
Summary
This section has described the literature about whether patients continue to take or continue to be prescribed the medicines they are prescribed at hospital
discharge. It has found that rates of adherence vary greatly and studies have found association between adherence and a range of patient and care
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characteristics. None of the studies explored the structure of patient care as a predictor of adherence, however two qualitative studies concluded that system-related problems contributed to sub-optimal medicines use. A range of terms are used, each describing slightly different phenomena, for example adherence, persistence and continuity. Discrepancies and changes were also explored.
Studies described here tended to be deterministic, rather than interpretivist;
they attempted to measure and predict causes of behaviour, rather than describe, explore and understand them. They did not focus on contextual factors, such as the structure of the care experienced by patients relating to their medicines, how they accessed healthcare providers, or the level of support they had with their medicines at home. As a result, most of the reviewed studies provide varying numeric assessments of rates of adherence, persistence and continuity without an extensive narrative that explains the reasons why patients may not take medicines as the hospital intended.
2.2.5 Medicines problems identified in community pharmacy after