Prevalence of infertility in the United States as estimated by the current duration approach and a traditional constructed approach.

OBJECTIVE: To estimate the prevalence of infertility using a current duration approach for comparison with a traditional constructed measure. DESIGN: Cross-sectional survey. SETTING: Not applicable. PATIENT(S): A nationally representative sample of females aged 15-44 years. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Infertility prevalence estimated by two approaches: [1] a constructed measure derived from questions on sexual activity, contraception, relationship status, and pregnancy, and [2] a measure based on estimated time to pregnancy derived from the respondents' current duration of pregnancy attempt (i.e., current duration approach). Associations with self-reported descriptive characteristics using weighted logistic regression or parametric survival models for each respective approach. RESULT(S): Infertility prevalence was approximately twofold higher using the current duration approach (15.5%; 95% confidence interval 8.6%-27.5%) vs. the constructed measure (7.0%; 95% confidence interval 6.2%-7.8%). Both methods identified similar patterns of increasing age, lower education, nulliparity, and history of gynecologic disorders as being associated with measures of impaired fecundity, whereas opposing patterns were seen for racial/ethnic identification and poverty status. CONCLUSION(S): Infertility prevalence based on a current duration approach was consistent with other US prospective cohort studies with preconception enrollment. These findings underscore the importance of definition and methodologic approach for estimating the prevalence of infertility.

Unintentional injuries among youth with developmental disabilities in the United States, 2006-2007.

We examined unintentional injury among youth with and without developmental disabilities. Our nationally representative sample included 6369 injured youth, aged 0-17 years, who were seen in one of the 63 US hospital emergency rooms that participated in the National Electronic Injury Surveillance System - All Injury Program (NEISS-AIP) in 2006-2007. Parents or guardians of injured youth were interviewed by telephone after the hospital visit to ascertain disability status. Denominator data were obtained from the National Health Interview Survey. Leading causes of injury were comparable for youth with and without disability. Injury rates (per 100 youth per year) were also comparable [10.4; 95% confidence interval (CI) 7.8, 13.0 and 10.5; 95% CI 8.2, 12.9, for youth with and without disability, respectively]. When examined by specific disability, the rate ratio for youth with learning disabilities versus youth without learning disability was 1.57 (95% CI 1.04, 2.10), which may represent a subgroup for targeted interventions.

Preventing young children's injuries: analysis of data from a population-based surveillance.

The objective of this study is to determine prevention strategies for potentially serious injury events among children younger than 3 years of age based upon circumstances surrounding injury events. Surveillance was conducted on all injuries to District of Columbia (DC) residents less than 3 years old that resulted in an Emergency Department (ED) visit, hospitalization, or death for 1 year. Data were collected through abstraction of medical records and interviews with a subset of parents of injured children. Investigators coded injury-related events for the potential for death or disability. Potential prevention strategies were then determined for all injury events that had at least a moderate potential for death or disability and sufficient detail for coding (n = 425). Injury-related events included 10 deaths, 163 hospitalizations, and 2,868 ED visits (3,041 events in total). Of the hospitalizations, 88% were coded as moderate or high potential for disability or death, versus only 21% of the coded ED visits. For potentially serious events, environmental change strategies were identified for 47%, behavior change strategies for 77%, and policy change strategies for 24%. For 46% of the events more than one type of prevention strategy was identified. Only 8% had no identifiable prevention strategy. Prevention strategies varied by specific cause of injury. Potential prevention strategies were identifiable for nearly all potentially serious injury events, with multiple potential prevention strategies identified for a large fraction of the events. These findings support developing multifaceted prevention approaches informed by community-based injury surveillance.

Association between swimming lessons and drowning in childhood: a case-control study.

OBJECTIVE: To estimate the association between swimming lessons and the risk of drowning among children aged 1 to 19 years. DESIGN: Case-control study. SETTING: Cases were identified from medical examiners'/coroners' offices between mid-2003 and mid-2005. Jurisdictions included the states of Maryland and North Carolina, 14 districts (33 counties) in Florida, 3 counties in California, 1 county in Texas, and 1 county in New York. PARTICIPANTS: Cases were children and adolescents aged 1 to 19 years who died of unintentional drowning. Interviews were conducted with 88 families of children who drowned and 213 matched controls. Main Exposure Swimming lessons. Main Outcome Measure Death due to unintentional drowning. Drownings that were intentional, of undetermined intent, or that occurred under conditions in which swimming ability was unlikely to impact risk (eg, in ice water or bathtubs) were excluded. RESULTS: Of the 61 cases in the 1- to 4-year age group, 2 (3%) had participated in formal swimming lessons vs 35 of 134 matched controls (26%) (adjusted odds ratio [OR], 0.12; 95% confidence interval [CI], 0.01-0.97). Among the 27 cases aged 5 to 19 years, 7 (27%) had ever taken formal swimming lessons vs 42 of 79 matched controls (53%) (adjusted OR, 0.36; 95% CI, 0.09-1.51). In adjusted analyses, there was no statistically significant association between informal instruction and drowning risk. CONCLUSIONS: Participation in formal swimming lessons was associated with an 88% reduction in the risk of drowning in the 1- to 4-year-old children, although our estimates were imprecise and 95% CIs included risk reductions ranging from 3% to 99%.

Participation of next of kin in research following sudden, unexpected death of a child.

OBJECTIVE: To assess parents' perceptions of their experience being interviewed after the sudden, unexpected death of their child. DESIGN: Case-control study in which cases were victims of unintentional drowning. SETTING: Households of recent drowning victims in 6 states in the United States. PARTICIPANTS: Caregivers (primarily parents) of 87 cases and 491 matched controls were interviewed via telephone about their child. MAIN EXPOSURE: Recent death of a child by unintentional drowning. MAIN OUTCOME MEASURES: Degree of stress related to interview, perception of interview length, and participants' views about their willingness to participate in this type of interview again, given their experience with the current interview. RESULTS: Although case participants were more likely than controls to perceive the interview as somewhat or very stressful (odds ratio, 3.64; 95% confidence interval, 1.67-7.96), most of the case participants (87.2%) and controls (96.1%) perceived the interview to be not at all or a little stressful. A greater percentage of controls (37.8%) found the interview to be too long, compared with case participants (20.9%). Among case participants, perceived stress during the interview and the perceived length of the interview were not associated with willingness to participate again. Both of these associations were significant (P<.001) for controls. CONCLUSIONS: Caregivers who chose to participate in the study generally rated their experiences as not very stressful. Most of the caregivers indicated that they would be willing to participate again in a similar study.

Swimming pool drownings among US residents aged 5-24 years: understanding racial/ethnic disparities.

OBJECTIVE: We examined circumstances surrounding swimming pool drownings among US residents aged 5 to 24 years to understand why Black males and other racial/ethnic groups have high drowning rates. METHODS: We obtained data about drowning deaths in the United States (1995-1998) from death certificates, medical examiner reports, and newspaper clippings collected by the US Consumer Product Safety Commission. RESULTS: During the study period, 678 US residents aged 5 to 24 years drowned in pools. Seventy-five percent were male, 47% were Black, 33% were White, and 12% were Hispanic. Drowning rates were highest among Black males, and this increased risk persisted after we controlled for income. The majority of Black victims (51%) drowned in public pools, the majority of White victims (55%) drowned in residential pools, and the majority of Hispanic victims (35%) drowned in neighborhood pools (e.g., an apartment complex pool). Foreign-born males also had an increased risk for drowning compared with American-born males. CONCLUSIONS: Targeted interventions are needed to reduce the incidence of swimming pool drownings across racial/ethnic groups, particularly adult supervision at public pools.

Effects of folic acid fortification on twin gestation rates.

OBJECTIVE: Previous studies have reported an increase in twinning of as much as 40% associated with folic acid-containing supplements, and folic acid fortification of enriched cereal grains was authorized in 1996. The purpose of this study was to investigate whether twinning rates have increased since that time. METHODS: We used United States birth and fetal death records to calculate twin gestation rates from 1990 through 2000. To eliminate the influence of fertility treatments, our analysis was limited to nulliparous women aged 16-19. We compared time trends in twin gestation rates before and after folic acid fortification in 1996. RESULTS: A total of 25,065 twin and 3,362,245 singleton pregnancies were included. Twin gestation rates were stable from January 1990 through December 1996, at 7.2 per 1,000, and then began a steady increase, averaging 2.4% (95% confidence interval 0.1-4.2%, P = .006) per year, which continued through 2000 and reached 8.2 per 1,000. This translates to 2 additional twin pregnancies per 10,000 gestations per year. Twin rates continued to increase well beyond 1998, when the maximal fortification effect on folate status had been reached. CONCLUSION: Although twin gestation rates in women not using fertility treatments increased after food fortification with folic acid, they rose by much less than the 40% rate previously reported; the observed pattern of increase in twin gestation rates is not consistent with a folic acid fortification effect. LEVEL OF EVIDENCE: II-2.

National underascertainment of sudden unexpected infant deaths associated with deaths of unknown cause.

OBJECTIVE: To investigate underascertainment of unexpected infant deaths at the national level as a result of probable classification as attributable to unknown cause. METHODS: Using linked birth and death certificates for all US birth cohorts from 1983-1991 and 1995-1996, we identified 53 470 sudden infant death syndrome (SIDS) fatalities, 9071 unintentional injury deaths, 3473 injury deaths classified with intentional or suspicious intent, and 8097 deaths with unknown underlying cause. For these deaths, we compared relative risks (RRs) for maternal and infant variables available on birth certificates known to be predictive of SIDS, unintentional injury, and homicides. Variables available on death certificates were compared for unlinked and linked records. Factors related to state and national management of cases pending final cause determination are reviewed. RESULTS: For deaths from unknown cause, rates were consistently high among the same risk groups that have been shown to be at increased risk for SIDS, unintentional injury, and homicides. For most risk factors, RRs for deaths attributable to unknown causes were somewhat lower than for RRs for intentional/suspicious injury deaths but higher than for SIDS or unintentional injury, indicating combined contributions from all causes. For example, age at death from unknown cause includes RRs that more strongly resemble patterns of intentional/suspicious injuries than SIDS or unintentional injury. Deaths from unknown cause were more likely to occur during the first week of life for unattended births occurring outside clinical settings or when birth certificates were not found, similar to intentional/suspicious injury deaths. CONCLUSIONS: Risk profiles indicate that deaths of unknown cause are likely to represent a mixture of unexpected deaths. The process for determination of cause of unexpected death affects national underascertainment of SIDS and injury deaths. Better coordination among child fatality review teams and local, state, and national officials should reduce underascertainment and improve documentation of circumstances surrounding deaths for prevention efforts.