Medication taking behaviour and medication adherence

It has been estimated that up to 50% of patients are non-adherent with their oral medication within a few months of discharge from hospital (Van Putten, 1974; Appelbaum and Gutheil, 1980a; Weiden and Olfson, 1995). A double-blind controlled study also showed that patients who defaulted on oral medication were also very likely to default on depot (intramuscular injections) medication and that both forms of maintenance medication had similar rates of relapse (Falloon et al. 1978).

Van Putten (1974) studied the reasons why patients were intentionally non-adherent with drug therapy. Between 24-63% of out-patients took less antipsychotic drug than prescribed. This study identified a relationship between drug reluctance and drug-induced extra- pyramidal side-effects (EPSE). He suggested that in-patients had a greater tolerance of EPSE compared with out-patients due to the greater impact on functioning in the community.

‘...an akinesia may cost a clerk typist her job; an oculogyric crisis may imperil the life of a man who needs to drive; or a tremor can be socially incapacitating to a self- conscious woman’.

Van Putten (1974) Thirty-five per cent of patients being treated with antipsychotic medication will relapse annually due to a lack of efficacy (Lecrubier and Meltzer, 1993). One of the most common reasons cited was a high incidence of EPSE. Sexual disturbance and weight gain have also been reported as important predictors of patients discontinuing their medication (Young et al. 1986; Buchanan, 1992). Paradoxically, not all literature supports a relationship between the presence of adverse effects and noncompliance ( Willcox et al. 1965; McEvoy et al.

1989a). Other studies have found that mild side-effects were not associated with non­ adherent behaviour (Hogan et al. 1983; Pan and Tantam, 1989). Therefore, simply substituting atypical antipsychotic drugs, whose side-effect profiles are improved, will not be sufficient to lead to complete adherence with drug therapy (Hale, 1993).

Factors associated with drug non-adherence have been identified to be not only a function of the medication (e.g. form type, regimen, adverse effects) but also a function of the patient, the illness, the health care professionals, the patient’s environment, the therapeutic setting or a combination of the above (Babiker, 1986; Flieschhacker et al. 1994a; Kissling, 1994;

Gerlach, 1994). Studies have shown that poor adherence with antipsychotic medication is related to personal variables such as culture and ethnic group, patient’s experiences, severity of illness, attitudes to treatment, insight into illness, poor relationship between patient and professionals, compulsory admission to hospital and a lack of social support (Appelbaum and Gutheil, 1980b; Marder et a l 1983; Kelly et a l 1987; Bartko et a l 1988; Pan and Tantam, 1989; Buchanan, 1992; Sellwood and Tarrier, 1994; Lecrubier and Meltzer, 1993).

Diamond (1983) reported a management strategy for enhancing a patient’s medication adherence:

• Medication should be put into the context of the patient’s life.

• Compliance should be of interest and concern to the professional and there should be an opportunity for constructive dialogue with the patient.

• The patients and all their significant contacts should be well informed about the medication.

• The patient’s extended support system should be involved in enhancing compliance. • The patient should be involved as much as possible in their medication.

• Health care professionals should be assertive in encouraging compliance.

• Contact should be maintained with the active drug defaulter to enhance opportunity for future cooperation and compliance.

Such a strategy highlights the level of involvement the health care professional should take. Non-adherence does not only represent a patient that resists or lacks the motivation to accept the medication or treatment plan that a clinician offers. Non-adherence may also represent the failure of the clinician to offer an appropriate clinical intervention that allows a better therapeutic outcome for that individual (Cohen, 1993). Non-adherence can be an expression of independence and a judgement about the utility of an intervention.

‘The quality of one’s life is a personally defined concept and so too are the reasons why a patient refuses to do what is recommended. Appropriate health behavior should be thought of as a behavior that meets the person’s goals and achieves some mutually definable outcome.’

(Liang, 1989) Kane (1987a) called for patients and their carers to be more involved in their drug therapy. The role of antipsychotic medication and the goals of treatment, especially during the acute

phase of the illness and long-term maintenance therapy should be understood. Similarly, the limitations of drug therapy should be clearly explained, i.e. that they do not cure the illness and they do not necessarily alleviate psychosocial and interpersonal difficulties.

Szabadi (1996) suggested that predicted adverse effects can promote medication adherence since it reassures the patient that the medication is working. Flieschhacker et al. (1994b) showed that noncompliance with haloperidol and clozapine drug therapy was not predicted by the incidence of parkinsonian symptoms in the first four-weeks of treatment. They explained this finding in relation to their approach to treatment. They devoted time to the provision of information and discussion about adverse effects with their patients, as well as the early treatment of adverse effects through dose reduction, concomitant drug therapy and change of antipsychotic medication. This study highlighted the potential importance of information exchange and an open relationship between the prescriber and patient. Flieschhacker et a l (1994b) concluded that a positive relationship between the physician and patient is not only an opportunity for information provision to the patient but also an opportunity to correct any misinformation in the patient’s health belief system.

Promising results have been obtained with behavioural and educational intervention programmes. For example, Boczkowski et al. (1985) carried out a controlled study comparing behavioural-tailoring (BT) and a psychoeducational intervention (PE) with people with chronic schizophrenia taking antipsychotic medication. BT focused on making the medication highly visible, pairing the medication regime with specific activities and providing a self-monitoring calendar. PE was an educational approach that centred on information about the illness and the needs for medication. BT participants were found to be significantly more adherent than either the PE or control group. Limitations of the study included the low correlation between the three measures of compliance: self-report, ratings by significant others and pill counts (pill counts were taken as the criterion measure) and also the short follow-up period of three months.

Kissling (1994) showed in a prospective study of people with schizophrenia in Germany, a 30% improvement in compliance and 20% decrease in readmission in the first year through a series of 8 psychoeducational sessions. He concluded that it is neither ethical nor

economically defensible to prescribe maintenance medication without compliance enhancing strategies such as psychoeducational interventions.

In another controlled study, Kemp et a l (1996) helped acutely psychotic in-patients to change their medication-taking behaviour using an active therapeutic approach with guided problem solving and an education component (‘compliance therapy’). Consecutively admitted patients (69% response rate) were randomly assigned to compliance therapy (n=25) or control treatment (supportive counselling with no discussion of treatment) (n=22). Four from each group were lost to follow-up. Compliance therapy showed an improvement in insight, attitudes and compliance in the short term (6 months). However, improvement in functioning was not obtained when a minimum standard of 50 on the Global Assessment Scale (Endicott et a l 1976) was analysed. A stepwise linear regression model explained 62.5% of the variance in compliance using detention under the Mental Health Act, extra pyramidal side-effects (EPSE) and attitudes to treatment as the explanatory variables. Caution has to be applied to the results due to the small numbers and because the observer (who rated functioning and compliance initially and at 3-months) was not blinded to the treatment group. Nevertheless ratings at 6-months were carried out by an independent assessor who was blinded.

Huxley and Warner (1992) reported reduced readmission rates due to enhanced medication adherence encouraged by patients receiving their welfare benefits simultaneously with their medication, assertive outreach and by close monitoring by case managers with small case loads.

A recent report ‘From compliance to concordance: achieving shared goals in medicine taking’ suggested that the term ‘concordance’ should replace the terms compliance and adherence (Royal Pharmaceutical Society of Great Britain and Merck Sharp and Dohme, 1997). Compliance was criticised for its paternalistic approach suggesting that a patient’s behaviour (as a passive receiver) should follow the ‘doctor’s orders’. The authors acknowledged that adherence suggested negotiation between the prescriber and the patient and that the patient had a choice but they still criticised adherence for the same ‘semantic overtones’ as compliance. The authors of the report justified the new term ‘concordance’

because it described the negotiated agreement between the prescriber and the patient and it did not focus on the behaviour of either party.

‘Concordance is based on the notion that the work of the prescriber and patient in the consultation is a negotiation between equals and that therefore the aim is a therapeutic alliance between them. This alliance, may in the end, include an agreement to differ. Its strength lies in a new assumption of respect for the patient’s agenda and the creation of openness in the relationship, so that both doctor and patient together can proceed on the basis of reality and not of misunderstanding, distrust or concealment.’

(Royal Pharmaceutical Society of Great Britain and Merck Sharp and Dohme, 1997:8) Limitations of this model include the assumption that all patients wish to negotiate as equals with the prescriber; this may not always be the case. Patients and their clinicians may be concordant in the consultation in relation to their views about medication but this does not infer that the patient will be adherent to the advice or treatment after leaving the consultation.

Other critics suggest that there are instances where the model of concordance does not apply (Milburn and Cochrane, 1997). They provided three examples: (1) clinical trials where incomplete compliance and adherence would lead to inconclusive results, (2) research into the human behaviour of medicine-taking and (3) the ethical considerations of allowing someone to decide which and how many medications to take when they have a fatal and infectious disease such as tuberculosis. Clearly, having the patient as the decision maker requires caution in situations where medication taking behaviour has implications beyond the treatment of an individual (Milburn and Cochrane, 1997). So, how appropriate is the model of ‘concordance’ with mental health patients? In this thesis the author (SAP) has continued to use the term adherence because the research focuses on the medication-taking behaviour of the respondents with their depot antipsychotic medication. However, the discussion (Chapter 11) will address the application of the concordance model with this patient group.