Evidencebased medicine and public health

1
Evidence-based medicine and public health

Ned Calonge, MD, MPH, Chief Medical
Officer Colorado Department of Public Health and
Environment
2
Objectives

• Discuss evidence-based medicine
• Discuss the role of evidence-based medicine in
  policy
• Discuss the impact of addressing Colorado health
  risks

3
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

4
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

5
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,
  dont 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, dont do it

6
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

7
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
  wouldnt 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

8
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 cant 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

9
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

10
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

11
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

12
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

13
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

14
A and B recommendationsaverage-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 (A)
• Osteoporosis (women 65) (B)
• Depression (B)
• Alcohol misuse screening and behavioral
  counseling (B)

15
D recommendations for average risk adults

• Bladder cancer
• Testicular cancer
• Pancreatic cancer
• Ovarian cancer
• Cervical cancer (low risk65/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

16
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)

17
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

18
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

19
Evidence and public policy

• State legislators often request that state-funded
  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

20
Influences on health policy

• Evidence competes with
• Politics
• Ideology
• Advocacy
• There are differences between
• Evidence-based
• Evidence-informed
• Data-driven

21
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

22
Prevention priorities

• National Commission on Prevention Priorities
  ranked all the USPSTF positive recommendations on
  the basis of preventable burden and cost
  effectiveness

23
Prevention prioritiestop 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

24
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

25
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
  non-smoking ordinances
• Provide no cost smoking cessation counseling

26
Tobaccoarguments 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

27
Tobaccoarguments 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

28
Colorado smoking
Source Behavioral Risk Factor Surveillance System
29
Colorado benefitstobacco 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

30
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?

31
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

32
Obesity under evaluation

• Transportation policy and infrastructure changes
  to promote non-motorized transit
• Urban planning approacheszoning 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

33
Colorado obesity
Source Behavioral Risk Factor Surveillance System
34
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

35
Colorado benefitshyperlipidemia

• 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

36
Colorado benefitshypertension

• 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
  un-diagnosed
• 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

37
Colorado benefitsbreast 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

38
Colorado benefitscervical 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

39
Colorado benefitscolon 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

40
Colorado life-years left on the table

• Smoking 75,000
• Obesity 55,000
• Cholesterol 35,870
• Hypertension 34,360
• Colo-rectal cancer 4,890
• Breast cancer 3,140
• Cervical cancer 800

41
Promoting wellness and preventing disease

• Increasing access to know effective preventive
  health care services will decrease premature
  death and disability

42
Promoting wellness and preventing disease

• However, the biggest health payoffs remain in the
  area of lifestyle
• Dont smoke
• Stay physically active
• Eat well (balance calories in and out, and
  balance source of calories)
• Decrease injury risks

43
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