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Learn about methodological changes impacting the tracking of Healthy People 2010 objectives, including revised definitions, measurement issues, and evolving estimates.
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TrackingHealthy People 2010 Objectives: Methodological andDefinitional Changes Kathleen M. Turczyn, MPH National Center for Health Statistics
Changes in tracking data can be due to: • Coding classifications (ICD-9 to ICD-10) • Revised OMB standards (1997) for race and ethnicity categories • Age-adjustment groups • Data source changes including question wording • Error in original measure • Preliminary analysis made final • New science
Three examples of changes in methodology and definitions • Objective 22-2 and LHI: Moderate physical activity among adults (NHIS) • Objective 3-9: Use of sun-protective behaviors among adults (NHIS) • Objective 5-12: Glycosylated hemoglobin measurement among adults with diabetes (BRFSS)
Objective 22-2Moderate physical activity • Increase the proportion of adults who engage regularly, preferably daily, in moderate physical activity for at least 30 minutes per day.
Objective 22-2Measurement issues • Change in NHIS questions asked between HP2000 and HP2010 • HP2010 definition needed to be re-conceptualized (regular activity) • Subsequent change in questions used for tracking HP2010 objective
Healthy People definitions of moderate physical activity • HP2000 and HP2010 definitions are similar: • Frequency of moderate activity is 5 or more times a week • Duration is 30 or more minutes each time
HP2000 physical activity • Periodic NHIS supplements (1985-98) • List of leisure-time physical activities • Continuum of activities • No activity • Moderate activity • Vigorous activity
HP2010 physical activity • Uses NHIS redesigned questionnaire core (1997+) • Separate questions for moderate and vigorous activity • Original baseline used 2 core questions: • Frequency of moderate activity • Duration of moderate activity
Original HP2010 questions used • How often do you do light or moderate activities for at least 10 minutes that cause only light sweating or a slight to moderate increase in breathing or heart rate? • Never • Unable to do • ____ times per day/week/month/year • About how long do you do these light or moderate activities each time? • _____ minutes/hours
New recommendation for HP2010 definition of moderate physical activity • Use both moderate and vigorous responses that meet criteria (closer to intent of objective – i.e., regular activity) • Use 4 questions: • Frequency and duration of vigorous activity • Frequency and duration of moderate activity
Vigorous physical activity questions • How often do you do vigorous activities for at least 10 minutes that cause heavy sweating or large increases in breathing or heart rate? • Never • Unable to do • ____ times per day/week/month/year • About how long do you do these vigorous activities each time? • _____ minutes/hours
Revised HP2010 operational definition of moderate physical activity • Light or moderate physical activity for at least 30 minutes 5 or more times a week, OR vigorous physical activity for at least 20 minutes 3 or more times a week
Final resolution for adult moderate physical activity objective • No change in the wording of the objective • New baseline: 32% in 1997 • New target: 50%
Objective 3-9Sun exposure and skin cancer • Increase the proportion of persons who use at least one of the following protective measures that may reduce the risk of skin cancer: • avoid the sun between 10 am and 4 pm • wear sun-protective clothing when exposed to sunlight • use sunscreen with a sun protective factor (SPF) of 15 or higher • avoid artificial sources of ultraviolet light
Objective 3-9bSun exposure and skin cancer among adults • Increase the proportion of adults aged 18 years and older who follow protective measures that may reduce the risk of skin cancer.
Objective 3-9bMeasurement issues • 1998 baseline questions differ from 2000 and 2003 questions • To use or not to use new 2000 data on respondents who offer that they “do not go out in the sun” in the analysis • To use or not to use the SPF question added to the 2000 and 2003 questionnaires
Questions used for 1998 baseline • If you were to go outside on a very sunny day for MORE than one hour, are you very likely, somewhat likely, or unlikely to… • wear protective clothing such as wide brimmed hats or long sleeved shirts? • avoid the sun by staying in the shade? • use sunscreen or sun block lotion?
Questions used for 2000 and 2003 updates • When you go outside on a very sunny day for more than one hour, how often do you… • stay in the shade? • wear a hat that shades your ears, face, and neck? • wear a long sleeved shirt? • wear sunscreen? [Response choices read after each question: always; most of the time; sometimes; rarely; never. “Don’t go out in the sun” was also coded as a response, but not asked.]
Why changes in question wording? • Questions and response choices should relate to the frequency of real behavior and not to a hypothetical likelihood of behavior • A 5-point scale is generally considered to be better than a 3-point scale
People who don’t go out in the sun (DGOITS) • The response “I don’t go out in the sun” to the sun protective behavior questions was recorded and coded but not specifically asked for in 2000 • How to use this information? • Are DGOITS at risk but engaging in a protective behavior? (radical sun protectionists) • Or are they not at risk because they spend their lives indoors? (not applicable subgroup) • Resolution: Exclude DGOITS from analysis (don’t know reason for behavior)
Use SPF question? • HP2010 objective wording includes the words “use sunscreen with a sun protective factor (SPF) of 15 or higher” • 1998 baseline did not include SPF numbers in the analysis (question was not asked) • In 2000, if respondents said they used sunscreen “all” or “most of the time,” they got a follow-up question: • What is the SPF number of the sunscreen you use MOST often? • Resolution: Use the SPF question
Evolving estimates of people reporting sun protective behaviors 58%
Final resolution for objective3-9b: Sun protection behaviors • Change the baseline data from 1998 to 2000 • New baseline is 58% • Target remains the same at 75%
Objective 5-12Glycosylated hemoglobin measurement among adults with diabetes • Increase the proportion of adults with diabetes who have a glycosylated hemoglobin measurement at least once a year.
Objective 5-12Measurement issues • 1998 baseline; BRFSS questions changed in 2000 • Substantial, real increase in people with diabetes getting A1C tests • To include or exclude “Never heard of A1C test” in the denominator in 2000
1998 baseline questions • Numerator: • Yes to “ever heard of glycosylated hemoglobin or hemoglobin A1C” • Had seen a health professional about diabetes one or more times in the last year • Had been checked by health professional for glycosylated hemoglobin A1C one or more times in the last year • Denominator: • Ever been told by a doctor that you have diabetes (for females, exclude if told only when pregnant)
2000 questions • Numerator: • Had seen a health professional about diabetes one or more times in the last year • “A test for hemoglobin A1C measures the average level of blood sugar over the past three months. About how many times in the past 12 months has a doctor, nurse, or other health professional checked you for hemoglobin A1C?” • Answer categories include “Never heard of A1C.” • Denominator: Ever been told by a doctor that you have diabetes (for females, exclude if told only when pregnant)
Why changes in question wording? • 1998 questions were confusing to respondents -- too many terms • Public health educators wanted people with diabetes to know specifically about the A1C lab test • Funding issue: The change shortens the questionnaire from 3 to 2 questions
* A short evolution of the estimates *Respondents who had “Never heard of A1C” were not asked about tests.
Final resolution for objective 5-12: Glycosylated hemoglobin measurement • Change the wording of the objective from “one or more” to “two or more…” • Possible other wording changes • Change the baseline year from 1998 to 2000 • New baseline is 63% • New target has yet to be determined (original target is 50%)
Websites NCHS Healthy People Homepage: www.cdc.gov/nchs/hphome.htm DHHS Healthy People Homepage: www.health.gov/healthypeople DATA2010: wonder.cdc.gov/data2010