Patient attitudes to commonly promoted medical interventions

However, consensus has also developed that patient empowerment, through complete specification of disease and treatment risks as well as likely outcome benefits, should be standard in any decision-making process.³ While evidence-based medicine may lead to a clear preference by doctors for treatment, acceptance of this same preference by patients, when apprised of all the relevant risks and benefits, has, to our knowledge, received limited study.^4,5 Moreover, Schwartz et al⁶ have presented findings which question the ability of many patients to comprehend elementary probability concepts, understanding that is crucial to any goal of patient empowerment. There are also reports which suggest that the necessity for proper, informed choice has been compromised,⁷ true risk odds overstated⁸ or biased epidemiological data presented⁹ to ensure patient participation. Such reports infer that patients may not necessarily perceive, or be able to perceive, the risk-benefit ratio for many treatments as favourably as their physicians.

The purpose of our study was to analyse the questionnaire-based attitudes of patients on the risks and benefits of a number of prominently promoted medical interventions.^10-12

The survey participants were also given an option to provide free-text comments for their responses. These were subsequently categorised into 10 general themes: the age at which intervention occurs; prior experience of the situation (either personal or acquaintances); the odds of success offered by the intervention; an aversion to taking any form of risk; a belief that life-events are predetermined; full confidence in doctors' advice; prefer alternative medicine procedures; insufficient information to make decision; a willingness to take any risk for better health; and all other reasons

The second survey was conducted at two general practice surgeries, which each received 50 questionnaires (May 1997). Each surgery's receptionist handled patient recruitment. The survey used the same questionnaire as the first survey, but without the "no difference" effect phrase, to assess whether this phrase had had an overly negative bias on patient scores.

After preliminary assessment of the two surveys, a third was conducted (October 1997) at a single general practice surgery, to assess the effect of a marked decrease in the risk-benefit ratio on patients' attitude towards HRT.

In all three surveys, patients were approached and asked to complete a questionnaire while waiting for their clinical consultation. One hundred questionnaires were made available for each survey, and each survey was conducted over a two-week period. There were no exclusion criteria for survey recruitment. The main reason for patient refusal was poor reading skills.

The demographic and other details of participants are shown in Box 1.

As the goal of our study was to assess patient attitudes in a prospective manner, age exclusion criteria (and cardiovascular disease comorbidity for HRT) consistent with the proposed intervention were applied before analysis.

The study was approved by the hospital ethics committee.

Thus, asymptomatic patients offered primary prevention for heart disease (HRT) had a very negative attitude, but viewed THROM and CABS treatment more favourably. This may reflect that patients consider these latter situations as potentially life-threatening and are therefore more willing to seek benefit (life) as a matter of urgency (see Box 3 free-text responses). Alternatively, it might be argued that the change in score relates to the absence of cancer as a potential side-effect, given the alarm this disease engenders.²⁴

We were able to demonstrate that lowering the risk-benefit for HRT led to a less negative attitude. Given the magnitude in risk-benefit reduction (fourfold) we consider the overall change modest, since even at this degree of risk-benefit the attitude towards HRT was still negative. We therefore believe that our findings are essentially robust with respect to moderate changes in risk-benefit.

A limitation of our study was the small sample size, which decreased the statistical power to detect differences. The external generalisability of the findings is also limited by a lack of information on participants' socioeconomic status and level of education. However, the similarity of attitude scores across the different settings infers a degree of robustness towards such confounders.

The favourable attitude towards CABS by patients with existing heart disease is consistent with a recent report that patients actively seek aggressive post-myocardial infarction treatment from their doctors.²⁵ The difference between the findings for THROM and CABS may reflect greater public awareness and expectations concerning CABS treatment.

It may be argued that our results, which show an overall equivocal attitude towards "best-practice" guidelines, are confounded by patients' inability to adequately interpret the probabilistic concepts.⁶ However, about 75% of patients providing written responses to the HRT questions indicated a clear aversion to any risk-taking; this same concern, although diminished, was also described for THROM and CABS. Moreover, for THROM and CABS, while a significant proportion of patients claimed that their decision was influenced by the odds, the actual median scores suggest the odds were viewed unfavourably.

A fundamental problem with evidence-based medicine, therefore, is that it encourages practices by physicians which may often conflict with the evolving paradigm of shared decision-making and even their own value judgements with respect to the risks and benefits of certain treatments. This is most likely to occur for preventive treatments, a medical strategy least favoured by our patients. It is also important to acknowledge that a decision by a patient that is different from that advocated by their physician does not imply the patient does not understand the information.²⁶

In conclusion, our findings show that patients have a variety of reasons for accepting or rejecting particular medical strategies, and, even where those reasons are based directly on risk-benefit outcomes, they are seldom as positive as proponents of evidence-based medicine might expect. Accordingly, widespread promulgation and instigation of "best-practice" guidelines for the medical interventions evaluated in this study would appear limited by any increasing patient role in the decision-making process.²⁷

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Reprints: Dr G Phillipov, Endocrinology, The Queen Elizabeth Hospital, Woodville, SA 5011.
gphillipovATtqehsmtp.tqeh.sa.gov.au