In Western health services, patients’ views of their treatment, and informed choice of treatment, are important concepts.1,2
Evidence suggests that patients want better information about treatment options and to be involved in decisions about which option to take.2
Being able to operationalize patient preferences
for treatment, reliably and validly, particularly for common conditions where different treatments offer potential benefits, is important for empowered patients and potential enhancement of doctor–patient relationships. By ‘preference’, we mean the expression of a value for alternative options for action after informed deliberation of their risks and benefits.3
This is a largely operational definition; conceptually, the idea of a preference is not well developed in the literature. For example, it is recognized that preferences may be influenced by a variety of factors – including experience, role preference, disease context, treatment context, sociodemographics, personality, information and general attitudes – but the extent to which these affect preferences are yet to be established.3
Nevertheless, it seems reasonable to suggest that preferences – alike to other values and attitudes – will be relatively resistant to change (stable).
Ischaemic heart disease, severe enough to cause symptoms of angina, is one common condition for which there are various equally viable treatments (each with varying benefit-to-risk profiles). There is evidence of wide variations in the age and sex of patients undergoing specific treatments for angina, such as coronary artery bypass surgery (CABG) and percutaneous coronary intervention (angioplasty).4
Given that treatment recommendations tend to be made by clinicians rather than patients making active treatment choices, these variations may
demonstrate inequities in access for women and older people.4,5
It has been reported, for example, that justifications for inequitable treatment of older people by clinicians include perceived lack of benefit, the belief that treatments for older people represent an inappropriate use of scarce resources and the perception that such patients do not want more invasive treatments.5
By and large, however, it is unclear to what extent patients themselves have been responsible for their treatment choices and to what extent treatment options have been selected for them by clinicians, as research is limited. Information on preferences is needed to ascertain whether
patients are receiving the treatment they prefer and to enable
preferred choice if this is desirable (informing clinical decision making).
Cross-sectional findings reported by Bowling et al.6
for a newly developed Patients Preferences Questionnaire for Angina treatment (PPQA) showed good psychometric properties. However, it is important to confirm the stability
of measured preferences over time (assuming that preferences are, like other values, relatively resistant to change), given that angina treatments are significant events that are not easy to reverse or revise once a decision is taken. Basing treatment choice on an instrument that results in variable and inconsistent choices over time would be problematic. Therefore, information on the stability of patients’ treatment preferences is required to lend confidence to the utility and validity of preference measures like the PPQA (as reliability is a necessary, though not necessarily sufficient, condition for instrument validity). Existing research on preference stability (more generally) is largely limited to utility studies of hypothetical
patients, or small convenience samples of actual patients.3
Using data from the same cohort of patients over time, this article reports the stability of patients’ preferences for treatment for angina assessed using the PPQA over an 18-month follow-up.