Draft Recommendation Statement
Skin Cancer Prevention: Behavioral Counseling
This opportunity for public comment expired on November 6, 2017 at 8:00 PM EST
Note: This is a Draft Recommendation Statement. This draft is distributed solely for the purpose of receiving public input. It has not been disseminated otherwise by the USPSTF. The final Recommendation Statement will be developed after careful consideration of the feedback received and will include both the Research Plan and Evidence Review as a basis.
Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
Draft: Recommendation Summary
|Fair-skinned persons ages 6 months to 24 years|
The USPSTF recommends counseling young adults, adolescents, children, and parents of young children about minimizing exposure to ultraviolet radiation for fair-skinned persons ages 6 months to 24 years to reduce their risk of skin cancer.
|Fair-skinned adults older than age 24 years|
The USPSTF recommends that clinicians selectively offer counseling to adults who have fair skin and are older than age 24 years about minimizing their exposure to ultraviolet radiation to reduce risk of skin cancer. Existing evidence indicates that the net benefit of counseling all adults older than age 24 years is small. In determining whether this service is appropriate in individual cases, patients and clinicians should consider the presence of risk factors for skin cancer.
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of counseling adults about skin self-examination to prevent skin cancer.
See the Clinical Considerations section for information on risk assessment and suggestions for practice regarding the I statement.
The U.S. Preventive Services Task Force (USPSTF) makes recommendations about the effectiveness of specific clinical preventive services for patients without obvious related signs or symptoms.
It bases its recommendations on the evidence of both the benefits and harms of the service and an assessment of the balance. The USPSTF does not consider the costs of providing a service in this assessment.
The USPSTF recognizes that clinical decisions involve more considerations than evidence alone. Clinicians should understand the evidence but individualize decisionmaking to the specific patient or situation. Similarly, the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clinical benefits and harms.
Skin cancer is the most common type of cancer in the United States, and is generally categorized as melanoma or nonmelanoma skin cancer. Melanoma is the fifth-leading type of incident cancer, and 2.2% of adults will be diagnosed with it in their lifetime. Although invasive melanoma accounts for only 2% of all skin cancer cases, it is responsible for 80% of skin cancer deaths. In 2014, 1.17 million persons were living with melanoma in the United States.1 Basal and squamous cell carcinoma, the two predominant types of nonmelanoma skin cancer, represent the vast majority of skin cancer cases. An estimated 3.3 million persons were diagnosed with nonmelanoma skin cancer in 2012.2
Recognition of Risk Status
UV radiation exposure during childhood and adolescence increases the risk of skin cancer later in life, especially when more severe damage occurs, such as with severe sunburns.3 Persons with fair skin, light hair and eye color, freckles, or those who sunburn easily are at increased risk of skin cancer.4 Persons who use tanning beds and those with a history of sunburns or previous skin cancer are also at greatly increased risk of skin cancer.5 Other factors that further increase risk include an increased number of nevi (moles) and atypical nevi,4 family history of skin cancer,6 HIV infection,7 and history of an organ transplant.8 Most studies of interventions to increase sun protection behaviors have been limited to populations with a fair skin type.
Benefits of Behavioral Counseling Interventions
Behavioral counseling interventions target sun protection behaviors to reduce UV radiation exposure. UV radiation is a known carcinogen9 that damages DNA and causes most skin cancer cases.10 Sun protection behaviors include the use of broad-spectrum sunscreen with a sun-protection factor of 15 or greater; wearing hats, sunglasses, or sun-protective clothing; avoiding sun exposure; seeking shade during midday hours (10 a.m. to 4 p.m.); and avoiding indoor tanning use.
The USPSTF found adequate evidence that behavioral counseling interventions available in or referable from a primary care setting result in a moderate increase in the use of sun protection behaviors in children, adolescents, and young adults ages 6 months to 24 years with fair skin.
The USPSTF found adequate evidence that behavioral counseling interventions available in or referable from a primary care setting result in a small increase in the use of sun protection behaviors in adults older than age 24 years with fair skin.
The USPSTF found insufficient evidence regarding the benefits of counseling adults about skin self-examination to prevent skin cancer.
Harms of Behavioral Counseling Interventions
The USPSTF found adequate evidence that the harms related to behavioral counseling interventions and sun protection behaviors in young persons or adults are small. The USPSTF found inadequate evidence regarding the harms of counseling adults about skin self-examination.
The USPSTF concludes with moderate certainty that behavioral counseling interventions have a moderate net benefit in children, adolescents, and young adults ages 6 months to 24 years with fair skin.
The USPSTF concludes with moderate certainty that behavioral counseling interventions have a small benefit in adults older than age 24 years with fair skin.
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of counseling adults about skin self-examination.
Draft: Clinical Considerations
This recommendation applies to asymptomatic persons without a history of skin cancer. Because most trials of skin cancer counseling predominantly include persons with a fair skin type, the USPSTF limited its recommendation to this population.
Assessment of Risk
Persons with a fair skin type (identified primarily by eye and hair color) are at increased risk of skin cancer and should be screened. Other factors that further increase risk include a history of sunburns, previous tanning bed use, freckling, and historical factors, such as usual reaction to sun exposure (e.g., usually burning, infrequently tanning). Persons with an increased number of nevi and atypical nevi are at increased risk of melanoma. Persons with a compromised immune system (e.g., persons living with HIV, persons who have received an organ transplant) are at increased risk of skin cancer.
Behavioral Counseling Interventions
All studies conducted in children and adolescents focused on sun protection behaviors; most were directed at parents, and some provided child-specific materials or messages. Half of the interventions included face-to-face counseling, and all included print materials. Three studies provided the intervention in conjunction with well-child visits. The majority of studies conducted in young adults and adults focused on improving sun protection behaviors, and two studies used “appearance-focused” messages. The mode of delivery varied and included mail-based, face-to-face or phone counseling, and technology-based (text messages, online programs and modules, personal UV facial photographs) interventions.11
Additional Approaches to Prevention
The Community Preventive Services Task Force recommends childcare center−based, primary and middle school−based, and multicomponent communitywide interventions for the prevention of skin cancer.12 These interventions combine school- and community-based communications and policy to increase preventive behaviors (e.g., covering up, using shade, or avoiding the sun during peak UV hours) among certain populations in specific settings.
The U.S. Food and Drug Administration (FDA) provides information to help guide patients and clinicians regarding sun protection and on the use and effectiveness of broad-spectrum sunscreens.13 The FDA has determined that broad-spectrum sunscreens with a sun-protection factor of 15 or greater, reapplied at least every 2 hours, protect against both UV A and B radiation and reduce the risk of skin cancer and early skin aging. The FDA also has consumer education materials on the dangers of indoor tanning.14
The USPSTF has issued a recommendation on screening for skin cancer in adults.15
Draft: Other Considerations
Interventions included tailored mailings, print materials, and in-person counseling by health professionals. Interventions for children were directed mostly toward parents; some materials were child-specific. Counseling interventions for children, their parents, or both provided messages focused on increasing sun protection behaviors (e.g., using sunscreen, avoiding midday sun, wearing sun-protective clothing). Some print-based interventions included materials tailored to the child’s level of risk, barriers to change, self-efficacy, or other factors. Some interventions provided sun protection aids (e.g., shirt, hat, sunscreen, sunglasses) in addition to counseling. Health professionals providing in-person counseling included primary care providers and health educators. Half of the studies in children had interventions longer in duration, from 18 to 36 months of counseling or tailored materials. The other half of studies in children had shorter interventions, ranging from a one-time counseling session to a 5-month period of standard mailings.
For adults, technology-based interventions included an interactive web program and tailored text messages on sun protection, as well as appearance-focused print materials. The web program study reported reduced sunburns after the intervention, which provided information on topics such as indoor tanning, UV radiation exposure and health, skin cancer, sunscreen, and skin examination. Each module took about 10 minutes to complete and included a goal-setting section. Other interventions that increased sun protection behaviors in adults included mailed print materials containing personalized risk feedback and recommendations, self-monitoring aids for UV exposure, and skin cancer prevention and detection information; individualized computer reports; and an interactive educational computer program on skin cancer prevention that provided individual feedback on personal skin cancer risk.
Research Needs and Gaps
A better understanding of the effectiveness of counseling on the use of sun protection behaviors in adults, including young adults, is needed to address the key evidence gap on counseling for this age group. Research that evaluates the association between UV exposure during adulthood and skin cancer risk would also be valuable. In addition, studies regarding the effectiveness of counseling persons without a fair skin type are lacking.
Ideally, research studies would provide measurements of sun exposure, sunburn, precursor skin lesions, and cancer among large trial populations, with an emphasis on behaviors and health outcomes among persons who receive an intervention focused on sun protection behaviors. Such studies would also assess whether these behaviors continue after trial completion. These cohorts should include racially/ethnically diverse populations as well as adolescents, young adults, and parents of preschool-age children. These studies may be used to further develop technologies and vehicles for administering relevant interventions for behavior change in the primary care setting, especially among non-Caucasian persons, young adults, and persons who practice indoor or outdoor tanning. Further evidence is needed to assess the balance of benefits and harms of counseling adults about skin self-examination to prevent skin cancer and premature death.
Burden of Disease
Skin cancer is by far the most common type of cancer. Melanoma is less common than basal or squamous cell carcinoma but has a much higher death rate. In 2017, an estimated 87,110 new cases of melanoma are expected, representing 5.2% of all new cancer cases. An estimated 9,730 persons will die of the disease, representing 1.6% of all cancer deaths. Although age-adjusted incidence rates have increased from 1989 to 2014 (from 13.7 to 25.2 cases per 100,000 persons), the death rate has remained fairly stable over the same period (from 2.7 to 2.6 deaths per 100,000 persons). Adults older than age 50 years; men; and persons with fair-colored skin, hair, or eyes are at increased risk. Melanoma is most frequently diagnosed among adults ages 65 to 74 years; death rates are highest among the middle-aged and elderly. Melanoma is more than 4.5 times more common among Hispanic persons and about 30 times more common among Caucasian persons than among African American persons.1
Nonmelanoma skin cancer, of which most cases are basal and squamous cell skin cancer, is associated with a substantial burden to the patient but rarely results in death. Basal cell skin cancer comprises about 80% of nonmelanoma skin cancer cases, and squamous cell skin cancer comprises about 20%. In general, nonmelanoma skin cancer accounts for a small percentage of all cancer deaths, mostly in older adults or persons with a compromised immune system. An estimated 2,000 persons die from nonmelanoma skin cancer each year. The true prevalence of nonmelanoma skin cancer is difficult to estimate because it is not a required cancer for registry entry; an estimated 5.4 million cases were diagnosed in 3.3 million persons in 2012.10
Scope of Review
The USPSTF commissioned a systematic evidence review to update its 2012 recommendation on behavioral counseling for the primary prevention of skin cancer16 and its 2009 recommendation on screening for skin cancer with skin self-examination.17 The review focused on direct evidence that counseling patients about sun protection reduces intermediate outcomes (e.g., sunburn or precursor skin lesions) or skin cancer. The review also sought evidence on the link between counseling and behavior change, the link between behavior change and skin cancer incidence, and the harms of counseling or changes in sun protection behavior. In addition, the review examined evidence regarding skin self-examination and skin cancer outcomes and the harms of skin self-examination.
Effectiveness of Counseling Interventions to Change Behavior
Many counseling interventions were found to be effective in modifying sun protection behaviors among children, adolescents, and young adults. Both traditional cancer prevention and appearance-focused messages (i.e., stressing the aging effects of UV radiation on the skin) increased sun protection behaviors compared to control groups.
Of six trials that evaluated the effect of interventions on sun protection behaviors among children and adolescents, five reported a statistically significant improvement in parent-reported composite scores of child sun protection behaviors compared to the control group. Four of the six trials specifically targeted children ages 3 to 10 years, one trial focused on children ages 0 to 3 years, and one trial focused on adolescents ages 11 to 15 years. Among the four trials, three showed statistically significant differences in changes in sun protection behavior and sunscreen use at 3 months and 3 years of followup.18-20
A cluster randomized, controlled trial21 that provided counseling to parents of newborns in a series of four well-child visits showed statistically significant improvement in composite sun protection scores in the intervention group. However, most individual measures were not statistically significant, and it was thus difficult to determine the clinical relevance of the small improvements. An in-person counseling intervention targeting adolescents and involving physicians and health educators showed that sun protection scores were higher in the intervention group than in the control group at 2 years of followup.22
Evidence of the effectiveness of counseling interventions in adults older than age 24 years is mixed. Six of 12 trials that addressed sun protection behaviors in adults found an increase in those behaviors, most commonly sunscreen use, compared to control groups. Three of these interventions promoted sun protection with tailored mailings, two used interactive online programs, and one used tailored text messages. Of three trials of self-reported indoor tanning behavior, only one trial using an appearance-focused intervention among young adult females noted a significant improvement compared to the control group.23 Effective interventions were more often of longer duration or had more frequent contacts with participants during the study period.
Trials of counseling interventions that focused on skin self-examination as a means of reducing skin cancer risk were inconclusive. A trial with more than 1,300 participants showed that those who received a skin self-examination counseling intervention did not have significant differences in the incidence of skin cancer cases or atypical nevi compared to those in the control group at 12 months of followup.24 Several studies showed that skin self-examination interventions increase the likelihood of participants reporting that they perform skin self-examination. Additional studies are needed to determine the direct effect of skin self-examination on skin cancer risk.
Link Between Behavior Change and Cancer Risk
Total and recreational sun exposure during childhood is associated with increased melanoma risk. Studies that measured long-term or total sun exposure showed mixed association between increased sun exposure and skin cancer risk. Several fair- to good-quality studies demonstrated a link between adult recreational UV exposure and increased melanoma risk.3 One large population-based study showed increased risk of both melanoma incidence and melanoma death with higher quartiles of UV exposure.25 Two recent meta-analyses and two cohort studies also showed an increased risk of nonmelanoma skin cancer in persons with increased ambient UV exposure.11
Indoor tanning is associated with increased melanoma risk, and younger age at first indoor tanning exposure increases this risk.26 A meta-analysis provided evidence of a dose-response relationship between melanoma risk and indoor tanning in women younger than age 50 years.27 Four studies found that increasing indoor tanning frequency was associated with increased melanoma risk. Two systematic reviews, one cohort study, and one case-control study found evidence that having ever used a tanning bed was associated with increased risk of squamous cell and basal cell carcinoma compared to never having used indoor tanning.
Two studies in adults provided new evidence of a protective effect of sunscreen use. One study, considered by the USPSTF for the previous recommendation statement, analyzed long-term followup data from a randomized, controlled trial. In this study, intervention group participants applied sunscreen daily while control group participants continued their usual behavior. At 4.5 years, the intervention group had a decreased risk of squamous cell carcinoma.28 Ten years after conclusion of the trial, half as many incident melanomas were identified in the intervention group as in the control group. Overall, melanoma risk was reduced in the intervention group compared to the control group and was most pronounced for invasive melanoma compared with in situ melanoma.29 A large U.S. case-control study also demonstrated a lower likelihood of melanoma in persons routinely using sunscreen compared to those who did not.30
Skin Self-Examination and Health Outcomes
Evidence on the effectiveness of skin self-examination in reducing death or illness is lacking. One 20-year followup study showed no association between skin self-examination and skin cancer death.31
Potential Harms of Counseling Interventions
Potential harms of interventions promoting sun protection behaviors include skin reactions to sunscreen lotion, vitamin D deficiency, reduced physical activity due to avoiding the outdoors, and a paradoxical increase in sun exposure from a false reassurance of protection due to sunscreen use. Sunscreen use can be associated with numerous transient skin reactions, including allergic, irritant, and photoallergic contact dermatitis. Although vitamin D deficiency is a hypothetical harm of sun avoidance, recent studies have not shown an association between sunscreen use and decreased vitamin D levels. Among the little evidence available, one study suggested that sun protection does not lead to decreased physical activity or increased body mass index. Older studies reported that sunscreen use did not result in an intentional increase in sun exposure, but two recent studies showed that sunscreen use was associated with higher odds of multiple sunburns.
Persons who performed skin self-examinations were more likely to have undergone a skin procedure compared to those who did not, as evidenced by one trial, indicating the potential harm of skin self-examination. Although melanoma death rates have remained stable, the increasing number of skin biopsies and rising melanoma incidence over recent decades provide evidence for overdiagnosis.32
Estimate of Magnitude of Net Benefit
The USPSTF determined that behavioral counseling interventions are of moderate benefit in increasing sun protection behaviors in children, adolescents, and young adults with fair skin. The link of behavior change to outcomes is supported by a body of evidence comprising several trials and a substantial body of observational evidence showing that the strongest connection between UV radiation exposure and skin cancer stems from exposure in childhood and adolescence. Evidence of a connection between sun exposure in adulthood and melanoma is less robust than in childhood. The USPSTF found adequate evidence that the harms related to counseling or sun protection behaviors are small. The USPSTF concluded with moderate certainty that the net benefit of counseling to decrease UV exposure and reduce skin cancer risk is moderate in children, adolescents, and young adults ages 6 months to 24 years.
The USPSTF found adequate evidence that behavioral counseling interventions result in a small increase in sun protection behaviors in adults older than age 24 years. The harms of counseling are small. The USPSTF determined that the evidence supporting a link between decreased UV radiation in adulthood and skin cancer risk is adequate. The USPSTF concluded with moderate certainty that the net benefit of counseling to decrease UV exposure and reduce skin cancer risk is small in adults older than age 24 years.
The USPSTF found inadequate evidence on the benefits and harms of counseling adults about skin self-examination to prevent skin cancer. Therefore, the USPSTF could not assess the balance of benefits and harms.
How Does Evidence Fit With Biological Understanding?
UV radiation from both solar and artificial sources has been classified as a human carcinogen by national and international organizations. Epidemiologic evidence suggests that the effect of UV radiation exposure from typical doses of sunlight varies over the lifespan, with some evidence of a window of biological vulnerability in childhood and adolescence that translates into increased skin cancer risk later in life. Much of the available evidence concerns the most common skin lesions, nonmalignant neoplasia and basal cell and squamous cell cancer. It remains unclear whether the same mechanisms apply to melanoma risk. For all three types of cancer, increasing intermittent or recreational sun exposure and total sun exposure are linked to increased risk. Artificial UV radiation, specifically indoor tanning, is also associated with an increased risk of skin cancer. Indoor tanning before age 35 years, for more than 10 tanning sessions over a lifetime, and for longer than 1 year have been linked to increased cancer risk.
Draft: Update of Previous USPSTF Recommendation
This recommendation replaces the 2012 USPSTF recommendation on counseling about skin cancer prevention16 and the skin self-examination portion of the 2009 USPSTF recommendation on screening for skin cancer.17 In this updated recommendation, the USPSTF expanded the age range for the recommendation on behavioral counseling interventions to include persons ages 6 months to 24 years with fair skin (the previous recommendation applied to persons ages 10 to 24 years). The USPSTF now also recommends that clinicians consider selectively offering counseling to adults older than age 24 years with fair skin. Evidence continues to be insufficient to assess the balance of benefits and harms of counseling adults about skin self-examination to prevent skin cancer, as it was in 2009.
Draft: Recommendations of Others
The U.S. Surgeon General,33 American Cancer Society,34 American College of Obstetricians and Gynecologists,35 American Academy of Pediatrics,36 Royal Australian College of General Practitioners,37 and the World Health Organization’s International Agency for Research on Cancer38 endorse the involvement of clinicians in counseling patients about skin cancer prevention.
The Community Preventive Services Task Force recommends education and policy approaches to encourage sun protection behaviors in child care centers, schools, recreational sites, and occupational settings. In addition, it recommends communitywide interventions that may or may not involve health care settings to increase protection behavior from UV radiation. Interventions include mass media campaigns and environmental and policy changes across multiple settings within a defined geographic area or an entire community.12
The American Academy of Dermatology encourages everyone to perform skin self-examination to check for signs of skin cancer.39 The American Cancer Society40 and the Skin Cancer Foundation41 recommend monthly skin self-examination. The Royal Australian College of General Practitioners recommends skin self-examination every 3 months for persons at high risk and annual clinical examination for those at low risk.42
1. National Cancer Institute. Cancer Stat Facts: Melanoma of the Skin. http://seer.cancer.gov/statfacts/html/melan.html. Accessed September 28, 2017.
2. American Cancer Society. Cancer Facts & Figures 2017. https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2017.html. Accessed Sep 28, 2017.
3. Lin JS, Eder M, Weinmann S, et al. Behavioral Counseling to Prevent Skin Cancer: Systematic Evidence Review to Update the 2003 U.S. Preventive Services Task Force Recommendation. Evidence Synthesis No. 82. AHRQ Publication No. 11-05152-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2011.
4. Khalesi M, Whiteman DC, Tran B, Kimlin MG, Olsen CM, Neale RE. A meta-analysis of pigmentary characteristics, sun sensitivity, freckling and melanocytic nevi and risk of basal cell carcinoma of the skin. Cancer Epidemiol. 2013;37(5):534-43.
7. Silverberg MJ, Leyden W, Warton EM, Quesenberry CP Jr, Engels EA, Asgari MM. HIV infection status, immunodeficiency, and the incidence of non-melanoma skin cancer. J Natl Cancer Inst. 2013;105(5):350-60.
10. American Cancer Society. About Basal and Squamous Cell Skin Cancer. https://www.cancer.org/cancer/basal-and-squamous-cell-skin-cancer/about.html. Accessed September 28, 2017.
11. Henrikson NB, Morrison CC, Blasi PR, Nguyen M, Shibuya KC, Patnode CD. Behavioral Counseling for Skin Cancer Prevention: A Systematic Evidence Review for the U.S. Preventive Services Task Force. Evidence Synthesis No. 161. AHRQ Publication No. 17-05234-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2017.
13. U.S. Food and Drug Administration. Sunscreen: How to Help Protect Your Skin From the Sun. https://www.fda.gov/Drugs/ResourcesForYou/Consumers/BuyingUsingMedicineSafely/UnderstandingOver-the-CounterMedicines/ucm239463.htm. Accessed September 28, 2017.
14. U.S. Food and Drug Administration. Indoor Tanning: The Risks of Ultraviolet Rays. https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm186687.htm. Accessed September 28, 2017.
27. Veierød MB, Adami HO, Lund E, Armstrong BK, Weiderpass E. Sun and solarium exposure and melanoma risk: effects of age, pigmentary characteristics, and nevi. Cancer Epidemiol Biomarkers Prev. 2010;19(1):111-20.
28. Green A, Williams G, Neale R, et al. Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial. Lancet. 1999;354(9180):723-9.
30. Lazovich D, Vogel RI, Berwick M, Weinstock MA, Warshaw EM, Anderson KE. Melanoma risk in relation to use of sunscreen or other sun protection methods. Cancer Epidemiol Biomarkers Prev. 2011;20(12):2583-93.
33. U.S. Department of Health and Human Services. The Surgeon General’s Call to Action to Prevent Skin Cancer. Washington, DC: U.S. Department of Health and Human Services, Office of the Surgeon General; 2014.
34. American Cancer Society. Skin Cancer Prevention and Early Detection. https://www.cancer.org/cancer/skin-cancer/prevention-and-early-detection.html. Accessed September 28, 2017.
35. American College of Obstetricians and Gynecologists. Committee opinion no. 626: the transition from pediatric to adult health care: preventive care for young women aged 18-26 years. Obstet Gynecol. 2015;125(3):752-4.
37. Royal Australian College of General Practitioners. Guidelines for Preventive Activities in General Practice. 8th ed. East Melbourne, Australia: Royal Australian College of General Practitioners; 2012.
39. American Academy of Dermatology. Skin Cancer. https://www.aad.org/media/stats/conditions/skin-cancer. Accessed September 28, 2017.
40. American Cancer Society. Melanoma Skin Cancer. https://www.cancer.org/cancer/melanoma-skin-cancer.html. Accessed September 28, 2017.
41. Skin Cancer Foundation. Early Detection and Self Exams. http://www.skincancer.org/skin-cancer-information/early-detection. Accessed September 28, 2017.
Internet Citation: Draft Recommendation Statement: Skin Cancer Prevention: Behavioral Counseling. U.S. Preventive Services Task Force. October 2017.