adherent, with non-adherence leading to organ rejection or death in 30 per cent of
non-adherent cases, compared to only 1 per cent among adherent patients. Non-
adherence is problematic because it means that when health care professionals make
accurate diagnoses of a health problem and prescribe effective treatment their
intervention may, nonetheless, be ineffective. Indeed, 10–25 per cent of hospital
admissions have been attributed to non-adherence. Thus the potential cost-effectiveness
of health care services is severely limited by non-adherence.
How can we measure adherence?
Simple self-report measures can provide good estimates of adherence (Morisky, Green
and Levine, 1986) but when self-report measures are compared to objective measures,
results indicate that patients overestimate their adherence (Myers and Midence, 1998).
This can mean that treatment ineffectiveness is wrongly attributed to the treatment,
rather than patients’ failure to adhere (Blaschke et al., 2012). Direct indicators such
as analyses of urine or blood content and weight change as well as indirect objective
measures such as pill counts, refill records and service usage records are also used to
track adherence. In addition, indirect measures such as health improvement (e.g. blood
pressure or hospitalization) may be employed as measures of adherence (Roter et al.,
1998).
Antecedents of adherence
Why do patients not follow advice? Patients are non-adherent for different reasons
(Donovan and Blake, 1992). Some patients intend to take recommended actions but
forget or find it difficult to do so, resulting in partial adherence. Others suspend
medication or test their health or to avoid side effects that might impinge on important
social events (Conrad, 1985). Some patients fear medication dependency while others
disagree with the doctor’s diagnosis or the prescribed treatment and deliberately take
more or less than was advised. Knowing why patients do not adhere is important to
designing interventions that may promote better adherence. Some key questions that
influence patients’ decisions to adhere are: Do I really need this treatment? Am I at
risk of symptoms without doing what was advised? How effective/beneficial is the
recommended action? What side effects will it have? To what extent will adherence
conflict with other things I want to do? When consultations do not adequately answer
these questions patients may reach their own conclusions and decide against adherence
(see Activity 8.1).
In the past, adherence was referred to as ‘compliance’ but this term is rarely used
now because it suggests that the patient’s role is to follow orders given by health care
professionals. In reality, patients decide whether the advice they receive is helpful and
whether or not they will follow it. Consequently, health care professionals need to
collaborate with and persuade patients if they are to shape their health-related
behaviours.
If a patient feels her doctor is not interested in her problem or has not under-
stood it, this will undermine confidence in the doctor’s advice. Consequently, patient
satisfaction is significantly correlated with adherence (r= 0.26, Ley, 1988). For exam -
ple, in a well-known study of paediatric consultations, Korsch, Gozzi and Francis
234 RELATING TO PATIENTS