of screening programmes; and (3) the possible psychological side effects of screening on
the individual. These criticisms constitute what can be seen as a backlash against the
screening of populations.
Is screening ethical?
Debates about the ethical issues surrounding screening have traditionally been polarized
between what Sackett and Holland (1975) referred to as ‘the evangelists and snails’.
These debates are best understood within the context of the four major ethical prin-
ciples relating to decision-making principles in medicine: beneficence, non-maleficence,
autonomy and justice.
Beneficence – screening as beneficial to the patient
Beneficence refers to the likelihood that any benefits to the patient will outweigh any
burdens. Screening should therefore bring about benefits to the patient in terms of
detecting a treatable disease or abnormality and enabling the individual’s life to be
prolonged or enhanced. There is evidence both in favour and against screening as a
benefit to the patient.
Evidence for beneficence In terms of screening for hypertension, Hart (1987) has
argued ‘we are surely under a moral if not legal obligation to record blood pressure at
least once in every 5 year span for every registered adult in our practice’. In terms of
cervical screening it has been estimated that for every 40,000 smears, one life has been
saved (Lancet 1985). In terms of breast cancer, reports from the Health Insurance Plan
Study (Shapiro et al. 1972; Shapiro 1977) suggested that early detection of breast can-
cer through screening reduced mortality in the study group compared with the control
group by 30 per cent. Results at follow-up indicated that the study group were still
benefiting after 12 years (Shapiro et al. 1982). Further results concerning the benefits of
breast screening have been reported following a large random controlled trial in Sweden
(Lundgren 1981). Hinton (1992: 231) concluded from his review of the literature that
‘lives may be saved by annual mammographic screening’. Jones (1992) argued that
screening for colorectal cancer may also be beneficial. He suggested that the ‘evidence
and arguments... are becoming compelling’ and noted that the death rate due to
colorectal cancer was ten times that due to cervical cancer, for which there is an existing
screening programme. In addition, the identification of the absence of illness through
screening may also benefit the patient in that a negative result may ‘give health back to
the patient’ (Grimes 1988). Therefore, according to the ethical principle of beneficence,
screening may have some positive effects on those individuals being screened.
Evidence against beneficence Electronic foetal monitoring was introduced as a
way of improving obstetric outcomes. However, the results from two well-controlled
trials indicated that such monitoring may increase the rate of Caesarean section without
any benefit to the babies both immediately after birth (MacDonald et al. 1985) and at
4 years of age (Grant and Elbourne 1989). In addition, electronic foetal monitoring
SCREENING 221