National Center for Health Statistics Guidelines for Analysis of Trends.

Many reports present analyses of trends over time based on multiple years of data from National Center for Health Statistics (NCHS) surveys and the National Vital Statistics System (NVSS). Trend analyses of NCHS data involve analytic choices that can lead to different conclusions about the trends. This report discusses issues that should be considered when conducting a time trend analysis using NCHS data and presents guidelines for making trend analysis choices. Trend analysis issues discussed include: choosing the observed time points to include in the analysis, considerations for survey data and vital records data (record level and aggregated), a general approach for conducting trend analyses, assorted other analytic issues, and joinpoint regression. This report provides 12 guidelines for trend analyses, examples of analyses using NCHS survey and vital records data, statistical details for some analysis issues, and SAS and SUDAAN code for specification of joinpoint regression models. Several an lytic choices must be made during the course of a trend analysis, and the choices made can affect the results. This report highlights the strengths and limitations of different choices and presents guidelines for making some of these choices. While this report focuses on time trend analyses, the issues discussed and guidelines presented are applicable to trend analyses involving other ordinal and interval variables.

Health characteristics of Medicare traditional fee-for-service and Medicare Advantage enrollees: 1999-2004 National Health and Nutrition Examination Survey linked to 2007 Medicare data.

BACKGROUND: National Health and Nutrition Examination Survey (NHANES) records have been linked to health care use and expenditure information from Medicare records. Claims data are generally available only for traditional fee-for-service (FFS) enrollees and not for Medicare Advantage enrollees. Differences in health characteristics between Medicare Advantage and traditional FFS enrollees could affect conclusions from analyses of the linked files that are restricted to traditional FFS enrollees. METHODS: Data from the 1999-2004 NHANES linked to the 2007 Medicare enrollment data were analyzed. Using examination and interview data collected in NHANES, we compared health characteristics of Medicare beneficiaries aged 65 and over at the NHANES interview by their type of Medicare enrollment in 2007. RESULTS: We found that the overall percentage of Medicare beneficiaries who had hypertension at the time of the NHANES medical examination was lower for Medicare Advantage enrollees compared with traditional FFS enrollees; this was found for the non-Hispanic white population but not for other race and ethnicity groups. We found no statistically significant differences between Medicare Advantage and traditional FFS enrollees overall or within race and ethnicity groups for other health characteristics that were measured or reported at the time of the NHANES interview or medical examination in 1999-2004. CONCLUSIONS: Despite finding no large differences in health characteristics by Medicare enrollment in this analysis, users of the National Center for Health Statistics Medicare linked files should consider potential differences in health characteristics between Medicare Advantage and traditional FFS enrollees that could influence results limited to traditional FFS beneficiaries only.

Health insurance affects diagnosis and control of hypercholesterolemia and hypertension among adults aged 20-64: United States, 2005-2008.

Lack of health insurance presents a barrier to obtaining routine preventive care and early diagnosis and management of chronic conditions. In 2005-2008, approximately 23% of adults aged 20-64 had no health insurance. Hypercholesterolemia (high total cholesterol or taking medication to lower cholesterol) and hypertension (high blood pressure or taking medication to lower blood pressure) are major risk factors for cardiovascular disease, particularly when untreated and uncontrolled and are common among nonelderly adults. In 2005-2008, 23% of adults aged 20-64 had hypercholesterolemia and 23% had hypertension. The objective of this report is to quantify the association between health insurance coverage and the diagnosis and control of hypercholesterolemia and hypertension among persons with those conditions. The criteria used to define these conditions are provided in the "Definitions" section of the report.

Drug poisoning deaths in the United States, 1980-2008.

In 2008, the number of poisoning deaths exceeded the number of motor vehicle traffic deaths and was the leading cause of injury death for the fi rst time since at least 1980. During the past three decades, the poisoning death rate nearly tripled, while the motor vehicle traffic death rate decreased by one-half. During this period, the percentage of poisoning deaths that were caused by drugs increased from about 60% to about 90%. The population groups with the highest drug poisoning death rates in 2008 were males, people aged 45­54 years, and non-Hispanic white and American Indian or Alaska Native persons. The vast majority of drug poisoning deaths are unintentional (see Appendix table). Opioid analgesics were involved in more drug poisoning deaths than other specified drugs, including heroin and cocaine. Opioid analgesics were involved in nearly 15,000 deaths in 2008, while cocaine was involved in about 5,100 deaths and heroin was involved in about 3,000 deaths (data not shown). Deaths involving opioid analgesics may involve other drugs as well, including benzodiazepines (2). In addition to an increase in the number of deaths caused by drug poisoning, increases in drug use, abuse, misuse, and nonfatal health outcomes have been observed. In the past two decades, there has been an increase in the distribution and medical use of prescription drugs, including opioid analgesics (3). From 1999 to 2008, the use of prescription medications increased (4). In 2007­2008, 48% of Americans used at least one prescription drug in the past month and 11% of Americans used five or more prescriptions in the past month. Analgesics for pain relief were among the common drugs taken by adults aged 20­59 years (4). In 2009­2010, over 5 million Americans reported using prescription pain relievers nonmedically in the past month (that is, without a doctor's prescription or only for the experience or feeling they caused), and the majority of people using prescription pain relievers nonmedically reported getting the drugs from friends or family (5,6). From 2004 to 2008, the estimated rate of emergency department visits involving nonmedical use of opioid analgesics doubled from 49 per 100,000 to 101 per 100,000 (7). Government agencies and other organizations joined together to achieve great reductions in the number of deaths from motor vehicle crashes in the past three decades (8,9). A comprehensive approach, including improvements in the safety of vehicles; improvements in roadways; increased use of restraint systems, such as seat belts and child safety seats; reductions in speed; and also efforts to reduce driving under the influence of alcohol and drugs, contributed to the decline in motor vehicle related deaths (8,9). Using a comprehensive, multifaceted approach, it may be possible to reverse the trend in drug poisoning mortality.

Perinatal outcomes for Asian, Native Hawaiian, and other Pacific Islander mothers of single and multiple race/ethnicity: California and Hawaii, 2003-2005.

OBJECTIVES: We examined characteristics and birth outcomes of Asian/Pacific Islander (API) mothers to determine whether differences in outcomes existed between mothers of single race/ethnicity and multiple race/ethnicity. METHODS: We used data from California and Hawaii birth certificates from 2003 through 2005 to describe variation in birth outcomes for API subgroups by self-reported maternal race/ethnicity (single versus multiple race or API subgroup), and we also compared these outcomes to those of non-Hispanic White women. RESULTS: Low birthweight (LBW) and preterm birth (PTB) varied more among API subgroups than between mothers of single versus multiple race/ethnicity. After adjustment for sociodemographic and behavioral risk factors, API mothers of multiple race/ethnicity had outcomes similar to mothers of single race/ethnicity, with exceptions for multiple-race/ethnicity Chinese (higher PTB), Filipino (lower LBW and PTB), and Thai (higher LBW) subgroups. Compared with single-race non-Hispanic Whites, adverse outcomes were elevated for most API subgroups: only single-race/ethnicity Korean mothers had lower rates of both LBW (3.4%) and PTB (5.6%); single-race/ethnicity Cambodian, Laotian, and Marshallese mothers had the highest rates of both LBW (8.8%, 9.2%, and 8.4%, respectively) and PTB (14.0%, 13.7%, and 18.8%, respectively). CONCLUSIONS: Strategies to improve birth outcomes for API mothers should consider variations in risk by API subgroup and multiple race/ethnicity.

Increase in fatal poisonings involving opioid analgesics in the United States, 1999-2006.

KEY FINDINGS: Data from the National Vital Statistics System Mortality File. From 1999 through 2006, the number of fatal poisonings involving opioid analgesics more than tripled from 4,000 to 13,800 deaths. Opioid analgesics were involved in almost 40% of all poisoning deaths in 2006. In 2006, the rate of poisoning deaths involving opioid analgesics was higher for males, persons aged 35-54 years, and non-Hispanic white persons than for females and those in other age and racial/ethnic groups. In about one-half of the deaths involving opioid analgesics, more than one type of drug was specified as contributing to the death, with benzodiazepines specified with opioid analgesics most frequently. The age-adjusted death rate for poisoning involving opioid analgesics varied more than eightfold among the states in 2006.

Health insurance coverage trends, 1959-2007: estimates from the National Health Interview Survey.

OBJECTIVES: This report presents long-term trends in the number and percentage of persons under age 65 years with different types of health insurance coverage and with no coverage. It documents changes in how the National Health Interview Survey (NHIS) has collected information about coverage over almost 50 years. It also compares recent trends in coverage estimates based on the NHIS and the U.S. Census Bureau's Current Population Survey (CPS). METHODS: Estimates were derived from 32 years of the NHIS, from 1959 to 2007. The types of estimates available differ over these years, reflecting changes in the availability of different types of coverage and changes in the NHIS questions. Joinpoint regression was used to estimate average annual percent change over time and to identify statistically significant changes in trends. RESULTS: The percentage of persons under age 65 years with private coverage rose between 1959 and 1968, to 79%, remained stable until 1980, and then declined to 67% by 2007. During the 1980s, the percentage of persons with no coverage increased, while the percentage with private coverage declined and the percentage with Medicaid remained stable. Since 1990, the percentage of nonelderly persons without coverage has remained stable, but the number has increased by more than 6 million persons, to 43.3 million in 2007. During this period, the percentage with private coverage has continued to decline, while the percentage with Medicaid has increased. Recent trends in coverage based on the NHIS and CPS are similar.

State, regional, and national estimates of health insurance coverage for people under 65 years of age: National Health Interview Survey, 2004-2006.

OBJECTIVES: This report presents state, regional, and national estimates of the percentages of persons under 65 years of age who were uninsured, who had private health insurance coverage, and who had Medicaid or State Children's Health Insurance Program (SCHIP) coverage. METHODS: The estimates were derived from the Family Core component of the 2004-2006 National Health Interview Survey (NHIS). Three years of data were combined to increase the reliability of estimates. Regional and national estimates are based on data from all 50 states and the District of Columbia. State estimates are shown for the 41 states with at least 1000 NHIS respondents during 2004-2006. Differences between national and subnational estimates were tested for statistical significance to identify those regions and states that differ significantly from the U.S. overall. RESULTS: The results show that the percentage of persons under age 65 who lacked any insurance coverage at a point in time varied by 20 percentage points among the states. Almost all states that were significantly higher than the U.S. rate on the percentage uninsured were significantly lower than the U.S. rate on the percentage with private coverage and vice versa.

Self-reported age-related eye diseases and visual impairment in the United States: results of the 2002 national health interview survey.

OBJECTIVES: We sought to establish national data on the prevalence of visual impairment, blindness, and selected eye conditions (cataract, diabetic retinopathy, glaucoma, and macular degeneration) and to characterize these conditions within sociodemographic subgroups. METHODS: Information on self-reported visual impairment and diagnosed eye diseases was collected from 31,044 adults. We calculated weighted prevalence estimates and odds ratios with logistic regression using SUDAAN. RESULTS: Among noninstitutionalized US adults 18 years and older, the estimated prevalence for visual impairment was 9.3% (19.1 million Americans), including 0.3% (0.7 million) with blindness. Lifetime prevalence of diagnosed diseases was as follows: cataract, 8.6% (17 million); glaucoma, 2.0% (4 million); macular degeneration, 1.1% (2 million); and diabetic retinopathy, 0.7% (1.3 million). The prevalence of diabetic retinopathy among persons with diagnosed diabetes was 9.9%. CONCLUSIONS: We present the most recently available national data on self-reported visual impairment and selected eye diseases in the United States. The results of this study provide a baseline for future public health initiatives relating to visual impairment.

Financial barriers to mammography: who pays out-of-pocket?

OBJECTIVE: This study investigates how out-of-pocket payments for mammograms vary according to the characteristics of women and the states where they reside. METHODS: We conducted a cross-sectional analysis for women >or=40 years using data from the 2000 National Health Interview Survey (NHIS) Cancer Control Module linked with state characteristics. Descriptive tabulations and logistic regressions were used to examine characteristics associated with out-of-pocket payment for a woman's most recent mammogram for the subset of approximately 7000 women reporting a mammogram within the past 2 years. RESULTS: In 2000, the majority of women who received a mammogram within the past 2 years paid no out-of-pocket costs: 68% among those aged 40-64 and 85% among those aged >or=66. Among women aged 40-64 with a recent mammogram, characteristics associated with paying out-of-pocket for the last mammogram were white, non-Hispanic race/ethnicity, being uninsured, having non-HMO private coverage, place of residence outside the Northeast, in a non-metropolitan county, and in a state with low HMO penetration. CONCLUSIONS: Public insurance and HMO coverage have been especially effective in eliminating financial barriers to mammography, but women 40-64 years with public coverage still lag behind their privately insured counterparts in using mammography. Out-of-pocket costs remain a barrier to use for uninsured women. Older women, although less likely than younger women to pay out-of-pocket for mammograms, remain less likely to use mammography than younger women.

Methodologic implications of allocating multiple-race data to single-race categories.

OBJECTIVE: To illustrate methods for comparing race data collected under the 1977 Federal Office of Management and Budget (OMB) directive, known as OMB-15, with race data collected under the revised 1997 OMB standard. DATA SOURCES/STUDY SETTING: Secondary data from the 1993-95 National Health Interview Surveys. Multiple-race responses, available on in-house files, were analyzed. STUDY DESIGN: Race-specific estimates of employer-sponsored health insurance were calculated using proposed allocation methods from the OMB. Estimates were calculated overall and for three population subgroups: children, those in households below poverty, and Hispanics. PRINCIPAL FINDINGS: Although race distributions varied between the different methods, estimates of employer-sponsored health insurance were similar. Health insurance estimates for the American Indian/Alaska Native group varied the most. CONCLUSIONS: Employer-sponsored health insurance estimates for American Indian/Alaska Natives from data collected under the 1977 OMB directive will not be comparable with estimates from data collected under the 1997 standard. The selection of a method to distribute to the race categories used prior to the 1997 revision will likely have little impact on estimates of employer-sponsored health insurance for other groups. Additional research is needed to determine the effects of these methods for other health service measures.