Support of personalized medicine through risk-stratified treatment recommendations - an environmental scan of clinical practice guidelines

BACKGROUND: Risk-stratified treatment recommendations facilitate treatment decision-making that balances patient-specific risks and preferences. It is unclear if and how such recommendations are developed in clinical practice guidelines (CPGs). Our aim was to assess if and how CPGs develop risk-stratified treatment recommendations for the prevention or treatment of common chronic diseases. METHODS: We searched the United States National Guideline Clearinghouse for US, Canadian and National Institute for Health and Clinical Excellence (United Kingdom) CPGs for heart disease, stroke, cancer, chronic obstructive pulmonary disease and diabetes that make risk-stratified treatment recommendations. We included only those CPGs that made risk-stratified treatment recommendations based on risk assessment tools. Two reviewers independently identified CPGs and extracted information on recommended risk assessment tools; type of evidence about treatment benefits and harms; methods for linking risk estimates to treatment evidence and for developing treatment thresholds; and consideration of patient preferences. RESULTS: We identified 20 CPGs that made risk-stratified treatment recommendations out of 133 CPGs that made any type of treatment recommendations for the chronic diseases considered in this study. Of the included 20 CPGs, 16 (80%) used evidence about treatment benefits from randomized controlled trials, meta-analyses or other guidelines, and the source of evidence was unclear in the remaining four (20%) CPGs. Nine CPGs (45%) used evidence on harms from randomized controlled trials or observational studies, while 11 CPGs (55%) did not clearly refer to harms. Nine CPGs (45%) explained how risk prediction and evidence about treatments effects were linked (for example, applying estimates of relative risk reductions to absolute risks), but only one CPG (5%) assessed benefit and harm quantitatively and three CPGs (15%) explicitly reported consideration of patient preferences. CONCLUSIONS: Only a small proportion of CPGs for chronic diseases make risk-stratified treatment recommendations with a focus on heart disease and stroke prevention, diabetes and breast cancer. For most CPGs it is unclear how risk-stratified treatment recommendations were developed. As a consequence, it is uncertain if CPGs support patients and physicians in finding an acceptable benefit- harm balance that reflects both profile-specific outcome risks and preferences

Adjuvant therapy, not mammographic screening, accounts for most of the observed breast cancer specific mortality reductions in Australian women since the national screening program began in 1991

There has been a 28% reduction in age-standardised breast cancer mortality in Australia since 1991 when the free national mammographic program (BreastScreen) began. Therefore, a comparative study between BreastScreen participation and breast cancer age specific mortality trends in Australia was undertaken for two time periods between 1991 and 2007, where women aged 50–59 and 60–69 years, who were invited to screen, were compared to women aged 40–49 and 70–79 years who were not invited, but who did have access to the program. There were mortality reductions in all four age groups between 1991–1992 and 2007, resulting in 5,849 (95% CI 4,979 to 6,718) fewer women dying of breast cancer than would have otherwise been the case. Women aged 40–49 years, who had the lowest BreastScreen participation (approximately 20%), had the largest mortality reduction: 44% (95% CI 34.8–51.2). Women aged 60–69 years, who had the highest BreastScreen participation (approximately 60%), had the smallest mortality reduction: 19% (95% CI 10.5–26.9). As BreastScreen participation by invited women aged 50–69 years only reached a maximum of about 55–60% in 1998–1999, a decline in mortality in Australian women cannot be attributed to BreastScreen prior to this time. Thus, almost 60% of the Australian decline in breast cancer mortality since 1991 cannot be attributed to BreastScreen. Therefore, mammographic screening cannot account for most of the reductions in breast cancer mortality that have occurred in Australian women since 1991 and may have contributed to over-diagnosis. Most, if not all, of the reductions can be attributed to the adjuvant hormonal and chemotherapy, which Australian women have increasingly received since 1986