Evidence-based medicine and public health

Evidence-based medicine and public health Ned Calonge, MD, MPH, Chief Medical Officer Colorado Department of Public Health and Environment Objectives Discuss evidence-based medicine  Discuss the role of evidence-based medicine in policy  Discuss the impact of addressing Colorado health risks  Challenges for prevention Most important messages about prevention may not be getting through  Not everything that might work does work  Many potential services, limited clinical time  Services should be supported by good evidence before they are widely recommended  Evidence-Based Medicine (EBM)  The conscientious, explicit and judicious use of the best current evidence in making clinical decisions about the care of individual patients Evidence-based medicine  Base decisions on evidence of effectiveness and benefit » when there is evidence of benefit, do it » when there is evidence of no benefit or harm, don’t do it » when there is insufficient evidence to determine if there is benefit, be conservative: use individual discretion, but if there are harms or costs, don’t do it Why be so strict with uncertainty?     “New”, “novel”, “innovative”, “cutting edge”, “investigational”, “promising” are not synonyms for “effective” or “better”; the treatment could be ineffective or harmful We are often wrong Premature acceptance undermines the ability and incentive to do the research necessary to determine effectiveness Resources spent on ineffective treatment increase the cost of care with no benefits and remarkable harms Potential harms of screening  There are 5 things that can happen with a screening test, and 4 of them are bad: » False negative test (false reassurance, delay in diagnosis of treatable condition) » False positive test (unnecessary and potentially harmful diagnostic tests, treatment, and labeling) » Over-diagnosis (true positive, but disease wouldn’t progress and treatment unnecessary) » No benefit from early detection (diversion of resources from effective services)  Also, there may be harms intrinsic to the test itself Risks of screening (examples)  Prostate specific antigen » 50-80% of men have some prostate cancer at autopsy (USA) » Only 4% of US men die from prostate cancer, so most affected men will die with it and not from it; testing can’t tell aggressive cancer from indolent cancer » Work up of a positive test carries minor risks, but treatment carries great risks including death (1-2%), impotence, and urinary and/or rectal incontinence Risks of screening (examples)  Mammography » 3.9% of women die of breast cancer in the US » Remember risk reduction is at best 30% » You must screen about 1500 US women age 40 and above every two years for 10 years to save one life from breast cancer » A woman who begins annual screening at age 40 has a 90% chance of needing a biopsy for a false positive mammogram by the time she is 70 years old The U.S. Preventive Services Task Force (USPSTF) Independent panel of nationally recognized, non-federal experts experienced in primary care, prevention, evidence-based medicine, and research methods  Charged by Congress to:  » review the scientific evidence for clinical preventive services and » develop evidence-based recommendations for the health care community Steps in explicit process       Define question and outcomes of interest within an analytic framework Define and retrieve relevant evidence Evaluate the relevance, strength and quality of individual studies Synthesize and judge the certainty of effectiveness from the available evidence Determine balance of benefits and harms Link recommendation to certainty of judgment about net benefits Recommendation grades A - Strongly recommend benefits substantially outweigh harms B - Recommend benefits outweigh harms C - USPSTF makes no recommendation benefits and harms too closely balanced D - Recommend against routine use ineffective interventions or harms outweigh benefits I - Insufficient evidence to recommend for or against the intervention The I statement  Insufficient Evidence to recommend for or against the intervention (not a recommendation, but a conclusion) Common reasons:  Lack of evidence on clinical outcomes  Poor quality of existing studies  Good quality studies with conflicting results NOTE: There is a possibility of clinically important benefit, but more research is needed A and B recommendations— average-risk adults    Cervical cancer (A) Colorectal cancer (A) Breast cancer (B) Hypertension (A) Lipid disorders (A) Obesity (B) Tobacco counseling (A)         Chlamydia infection (sexually active women <25) (A) Osteoporosis (women >65) (B) Depression (B) Alcohol misuse screening and behavioral counseling (B) D recommendations for average risk adults Bladder cancer  Testicular cancer  Pancreatic cancer  Ovarian cancer  Cervical cancer (low risk>65/no cx)  Coronary artery disease  Peripheral artery disease  AAA in women  Hepatitis B and C  Syphilis, gonorrhea, genital herpes  Bacteriuria  HRT for chronic disease prevention  Breast cancer chemoprophylaxis  Beta-carotene use  I recommendations for average risk Lung cancer  Prostate cancer  Skin cancer  Oral cancer  Diabetes (average risk)  Glaucoma  Newborn hearing  Thyroid disease  Dementia  Suicide risk  Domestic and intimate partner violence  Low back pain  Diet counseling  Exercise counseling  Vitamins (A, C, E. folate, antioxidants)  Reasons for conflicting recommendations Test availability vs. evidence of efficacy  Evidence-based vs. consensus process  Clinical vs. intermediate outcomes  Consideration of possible harms  Effectiveness vs. efficacy  » ideal setting vs. real world Primary care vs. specialty perspective  Approach to uncertainty  » “do no harm” Non-evidence-based influences on prevention recommendations Local experts/clinical leaders  Community standards  Recommendations of expert panels  Advocacy groups  Entrepreneurialism  State and national laws  Marketplace demands  Implementation issues  Costs  Evidence and public policy State legislators often request that statefunded programs be “evidence-based”  However, sufficiency of evidence to support one side of a policy or another varies more than does the agreement of scientists  Influences on health policy  Evidence competes with: » Politics » Ideology » Advocacy  There are differences between: » Evidence-based » Evidence-informed » Data-driven Chronic disease and public policy There are a number of health care interventions that clearly benefit those with disease precursors or chronic disease  Policies that improve the delivery of effective preventive services will extend and enhance the life of the population  Prevention priorities  National Commission on Prevention Priorities ranked all the USPSTF positive recommendations on the basis of preventable burden and cost effectiveness Prevention priorities—top 12             Aspirin prophylaxis for heart disease Childhood immunizations Tobacco use screening and brief intervention Colorectal cancer screening Hypertension screening Influenza vaccination Pneumococcal vaccination Problem drinking screening and brief counseling Vision screening in the elderly Cervical cancer screening Cholesterol screening Breast cancer screening Colorado health facts (2005) 29,521 total deaths  6,282 cardiovascular disease deaths  1,595 stroke deaths  6,367 cancer deaths  » 1,523 lung cancer » 544 colon cancer » 524 breast cancer » 42 cervical cancer Tobacco control Evidence: tobacco use is bad  Anti-smoking interventions decrease bad health outcomes  Three interventions PROVEN to decrease tobacco use in a state:  » Increase the cost of cigarettes through taxation » Increase the barriers to smoking through nonsmoking ordinances » Provide no cost smoking cessation counseling Tobacco—arguments against effective policy enactment  Personal responsibility/nanny government » Evidence is clear that education is insufficient to change behavior » Most smokers start at a time when informed decision-making is not well-developed  Personal choice » Individuals can choose to not visit or work in an establishment where smoking is allowed Tobacco—arguments against effective policy enactment All taxes/all new taxes are bad  Enhanced revenue supports bigger government, which is bad  Some businesses might go under due to smoking bans  Government has no business in the behavioral lives of Americans  Colorado smoking Colorado 30 US California 25 Percent 20 15 10 93 94 95 96 97 98 99 00 01 02 03 04 20 19 19 19 19 19 19 19 20 20 20 20 20 05 Source: Behavioral Risk Factor Surveillance System Colorado benefits—tobacco control There are 910,000 adult smokers (19.8%)  Tobacco-related deaths = 6,250  » 450 second-hand smoke » 1,885 cardiovascular disease (CVD) » 1,370 lung cancer » 479 stroke » 1,526 lung disease » 540 other cancers  Preventing the 6,250 tobacco deaths would yield 75,000 life years Obesity Will surpass tobacco as the number one cause of preventable death and disease in the U.S.  Can policy affect a behavior as personal as diet?  Can policy affect a behavior as hard to impact as physical activity?  Obesity: evidence-based approaches  Informational approaches » Community-wide campaigns » “Point of decision” prompts School-based education  Non-family social support  Individually-adapted health behavior change  Environmental and policy approaches  Obesity: under evaluation Transportation policy and infrastructure changes to promote non-motorized transit  Urban planning approaches—zoning and land use  School-based nutrition programs  Community approaches to increase fruit and vegetable intake  Food and beverage advertising to children  Food and beverage availability, price, portion size, and labeling in restaurants  Colorado obesity 30 25 20 Percent 15 10 5 0 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 20 19 19 19 19 19 19 19 19 19 19 20 20 20 20 20 05 Source: Behavioral Risk Factor Surveillance System Colorado benefits--obesity 850,000 are obese (17.5%)  Approximately 5,000 deaths per year could be attributed to obesity  Preventing these deaths could realize 55,000 life years  Colorado benefits—hyperlipidemia      Hyperlipidemia treatment reduces the risk of death from CVD by 30% and stroke by 20% 35% have been told they have high cholesterol Some percentage of those affected are un-diagnosed Less than a third of those diagnosed are treated to effective levels Screening and treatment could prevent 1,885 CVD deaths and 319 stroke deaths per year for a sum of 35,870 life years realized by screening and treatment Colorado benefits—hypertension      Hypertension treatment reduces the risk of death from CVD by 25% and stroke by 40% 20% have been told they have hypertension Some percentage of those affected are undiagnosed Less than half of those diagnosed are treated to effective levels Screening and treatment could prevent 1,571 CVD deaths and 638 stroke deaths per year for a sum of 34,360 life years realized by screening and treatment Colorado benefits—breast cancer Mammography between age 50 and 75 reduces the risk of breast cancer death by 30%  Mammography use in this age group in Colorado is less than 75%  Screening the rest could save 157 lives and gain 3,140 life-years  Colorado benefits—cervical cancer  Cervical cancer and screening » Pap smears screening is associated with at least 95% decrease in cervical cancer death; less than 90% of Colorado women have adequate screening » The HPV vaccine covers 70% of the strains that cause cervical cancer » HPV vaccine will not replace Pap smear screening  There are 42 cervical deaths/year; screening could prevent 40 deaths and gain 800 life years; HPV vaccine would prevent 29 deaths and gain 580 life years Colorado benefits—colon cancer Screening can decrease the risk of death by at least 50-60%  77% have been screened with one modality or another in the past 5 years  Screening the rest would save 326 lives and gain 4,890 life-years  Colorado life-years left on the table Smoking:  Obesity:  Cholesterol:  Hypertension:  Colo-rectal cancer  Breast cancer  Cervical cancer  75,000 55,000 35,870 34,360 4,890 3,140 800 Promoting wellness and preventing disease  Increasing access to know effective preventive health care services will decrease premature death and disability Promoting wellness and preventing disease  However, the biggest health payoffs remain in the area of lifestyle: » Don’t smoke » Stay physically active » Eat well (balance calories in and out, and balance source of calories) » Decrease injury risks Conclusions Science and evidence adheres to a set of rules independent of politics, ideology and the market  Politics adheres to a set of rules that can be informed by science and evidence but are not governed by these inputs  There are potential years of life lost that could be impacted by health policy 