© Open University Press, 2004 Overview Prevention and screening Psychological predictors of screening The ethics and usefulness of screening? Psychological consequences of screening

© Open University Press, 2004 Three forms of prevention Primary prevention: modification of risk factors such as smoking, diet, etc. Secondary prevention: detecting an illness at an asymptomatic stage so its progression can be halted. Screening is secondary prevention. Tertiary prevention: rehabilitation or treatment of patient after diagnosis.

© Open University Press, 2004 Screening programs Screening programs for: Diabetes Cervical cancer Breast cancer Hypertension Obesity Prenatal screening for Down’s, cystic fibrosis, spina bifida, anemia

© Open University Press, 2004 Psychological predictors of uptake (participation in screening) What predicts variability in uptake? –Patient factors –Health professional factors –Organisational factors

© Open University Press, 2004 Patient factors and uptake Demographic factors: e.g. class, age, health status, home ownership, and smoking Health beliefs: e.g. beliefs about benefits, barriers, social norms, self efficacy and social norms Emotional factors: e.g. anxiety, fear, uncertainty, feeling indecent, reassurance Contextual factors: e.g. family prevalence, family discussion, triggering event

© Open University Press, 2004 Health professional factors and uptake Beliefs about screening: beliefs about clinical effectiveness, beliefs about cost, beliefs about time Beliefs about illness: seriousness, consequences, can it be treated? Experience of screening and illness: influence communication with patient

© Open University Press, 2004 Organisational factors and uptake Method of invitation: in person, opting in rather than out Place of screening: accessible, local, familiar Type of request: Mandatory vs. voluntary Cultural norms: large media campaigns can raise awareness

© Open University Press, 2004 Ethical issues in Screening Access/Justice: Unequal distribution of resources – healthy/wealthy people are more likely to be screened Beneficence: screening can prevent illness and limit progression Maleficence: Some screening procedures have harmful side effects (not just physical) –radiation from mammograms –false positives and/or detecting “illness” that isn’t really significant

© Open University Press, 2004 Headline -- Feb 21, 2002 Thursday, Feb. 21, 2002 U.S. urges women to get mammograms at 40 (Reuters) - Women 40 and older should get a mammogram every year or two, the U.S. government said on Thursday, weighing in firmly on the side of screening in a growing debate about whether the tests save lives.

© Open University Press, 2004 Policy "If you are 40 or older, get screened for breast cancer with mammography every one to two years“ HHS Secretary Tommy Thompson, 2/21/03

© Open University Press, 2004 Reality evidence that mammograms save lives is strongest for older women - those ages 50 to 69 the task force decided younger women probably would gain some benefit, even though there was no specific evidence -- US Preventive Services Task Force, February 2002

© Open University Press, 2004 With more reliance on “improved medical technology” we have “discovered” that more people are “sick” New spiral CT scans can detect hepatic lesions of 2 mm. In 1982, only 20 mm lesions could be detected MRI can detect abnormalities of the knee in 25% of healthy young men. MRI can find lumbar disc bulge in 50% of adults, many who have no back pain. The better the technology for looking, the more you will find.

© Open University Press, 2004 Percent of disk bulges discovered by MRI in volunteers without back pain (Jensen et al, 1994)

© Open University Press, 2004 Rethinking the Assumptions Few people are well -- most of us are “sick” It is okay to be sick Better methods for diagnosing our illnesses may produce harm

© Open University Press, 2004 Where does disease begin? Disease is a continuum. A detectable prostate tumor is at least one billion cells. Did it exist before it reached this size?

© Open University Press, 2004 Number of people affected by mild and severe spectrum disease (Fisher & Welsch, 1997) no symptoms mild spectrum incapacitating symptoms severe spectrum

© Open University Press, 2004 For mild spectrum disease, treatment harm may exceed benefit (Fisher & Welsch, 1997) Treatment Benefit Treatment Risk no symptoms mild spectrum incapacitating symptoms severe spectrum

© Open University Press, 2004 Effect of changing diagnostic thresholds of prevalence of hypercholesterolemia % Above % Above 240

© Open University Press, 2004 Guidelines for screening The disease must: –Be prevalent –Be serious –Be sufficiently defined for accurate diagnosis –Exist undiagnosed in many cases The screening test must –give meaningful information that will result in benefit to the patient – be accurate with good sensitivity (few false negatives) and specificity (few false positives)

© Open University Press, 2004 To conclude Screening involves detection at an asymptomatic stage Appropriate for serious illnesses, with a clear diagnosis and accurate test Uptake predicted by patient, professional and organisational factors Not always ethical Not always cost effective Can have negative psychological consequences