Association of Socioeconomic Status With Postdischarge Pediatric Resource Use and Quality of Life.

OBJECTIVES: Socioeconomic factors may impact healthcare resource use and health-related quality of life, but their association with postcritical illness outcomes is unknown. This study examines the associations between socioeconomic status, resource use, and health-related quality of life in a cohort of children recovering from acute respiratory failure. DESIGN: Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure clinical trial. SETTING: Thirty-one PICUs. PATIENTS: Children with acute respiratory failure enrolled whose parent/guardians consented for follow-up. MEASUREMENTS AND MAIN RESULTS: Resource use included in-home care, number of healthcare providers, prescribed medications, home medical equipment, emergency department visits, and hospital readmission. Socioeconomic status was estimated by matching residential address to census tract-based median income. Health-related quality of life was measured using age-based parent-report instruments. Resource use interviews with matched census tract data (n = 958) and health-related quality of life questionnaires (n = 750/958) were assessed. Compared with high-income children, low-income children received care from fewer types of healthcare providers (ß = -0.4; p = 0.004), used less newly prescribed medical equipment (odds ratio = 0.4; p < 0.001), and had more emergency department visits (43% vs 33%; p = 0.04). In the youngest cohort (< 2 yr old), low-income children had lower quality of life scores from physical ability (-8.6 points; p = 0.01) and bodily pain/discomfort (+8.2 points; p < 0.05). In addition, health-related quality of life was lower in those who had more healthcare providers and prescribed medications. In older children, health-related quality of life was lower if they had prescribed medications, emergency department visits, or hospital readmission. CONCLUSIONS: Children recovering from acute respiratory failure have ongoing healthcare resource use. Yet, lower income children use less in-home and outpatient services and use more hospital resources. Continued follow-up care, especially in lower income children, may help identify those in need of ongoing healthcare resources and those at-risk for decreased health-related quality of life.

Income-driven socioeconomic status and presenting illness severity in children with acute respiratory failure.

Children living in low socioeconomic communities are vulnerable to poor health outcomes, especially when critically ill. The purpose of this study was to investigate the association between socioeconomic status (SES) and illness severity upon pediatric intensive care unit (PICU) admission in children with acute respiratory failure. This secondary analysis of the multicenter Randomized Evaluation of Sedation Titration for Respiratory Failure clinical trial includes children, 2 weeks to 17 years old, mechanically ventilated for acute respiratory failure; specifically, subjects who had parental consent for follow-up and residential addresses that could be matched with census tracts (n = 2006). Subjects were categorized into quartiles based on income, with a median income of $54,036 for the census tracts represented in the sample. Subjects in the highest income quartile were more likely to be older, non-Hispanic White, and hospitalized for pneumonia. Subjects in the lowest income quartile were more likely to be Black, younger, and hospitalized for asthma or bronchiolitis, to have age-appropriate baseline functional status, and history of prematurity and asthma. After controlling for age group, gender, race, and primary diagnosis, there were no associations between income quartile and either Pediatric Risk of Mortality scores or pediatric acute respiratory distress syndrome. As measured, income-based SES was not associated with illness severity upon PICU admission in this cohort of patients. More robust and reliable methods for measuring SES may help to better explain the mechanisms by which socioeconomic affect critical illness.

Neurodevelopmental assessment of infants with congenital heart disease in the early postoperative period.

OBJECTIVE: Mortality rates for children with congenital heart disease (CHD) have significantly declined, resulting in a growing population with associated neurodevelopmental disabilities. American Heart Association guidelines recommend systematic developmental screening for children with CHD. The present study describes results of inpatient newborn neurodevelopmental assessment of infants after open heart surgery. OUTCOME MEASURES: We evaluated the neurodevelopment of a convenience sample of high-risk infants following cardiac surgery but before hospital discharge using an adaptation of the Newborn Behavioral Observation. Factor analysis examined relationships among assessment items and consolidated them into domains of development. RESULTS: We assessed 237 infants at a median of 11 days (interquartile range [IQR]: 7-19 days) after cardiac surgery and median corrected age of 21 days (IQR: 13-33 days). Autonomic regulation was minimally stressed or well organized in 14% of infants. Upper and lower muscle tone was appropriate in 33% and 35%, respectively. Appropriate response to social stimulation ranged between 7% and 12% depending on task, and state regulation was well organized in 14%. The vast majority (87%) required enhanced examiner facilitation for participation. Factor analyses of assessment items aligned into four domains of development (autonomic, motor, oral motor, and attention organization). CONCLUSION: At discharge, postoperative infants with CHD had impairments in autonomic, motor, attention, and state regulation following cardiac surgery. Findings highlight the challenges faced by children with CHD relative to healthy peers, suggesting that neurodevelopmental follow-up and intervention should begin early in infancy.

Maintaining Interrater Agreement of Core Assessment Instruments in a Multisite Randomized Controlled Clinical Trial: The Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE) Trial.

BACKGROUND: RESTORE (Randomized Evaluation of Sedation Titration for Respiratory Failure) was a cluster randomized clinical trial evaluating a sedation strategy in children 2 weeks to <18 years of age with acute respiratory failure supported on mechanical ventilation. A total of 31 U.S. pediatric intensive care units (PICUs) participated in the trial. Staff nurse rater agreement on measures used to assess a critical component of treatment fidelity was essential throughout the 4-year data collection period. OBJECTIVE: The purpose of the study is to describe the method of establishing and maintaining interrater agreement (IRA) of two core clinical assessment instruments over the course of the clinical trial. METHODS: IRA cycles were carried out at all control and intervention sites and included a minimum of five measurements of the State Behavioral Scale (SBS) and Withdrawal Assessment Tool-Version 1 (WAT-1). Glasgow Coma Scale scores were also obtained. PICUs demonstrating <80% agreement repeated their IRA cycle. Fleiss's kappa coefficient was used to assess IRA. RESULTS: Repeated IRA cycles were required for 8% of 226 SBS cycles and 2% of 222 WAT-1 cycles. Fleiss's kappa coefficients from more than 1,350 paired assessments were .86 for SBS and .92 for WAT-1, demonstrating strong agreement and similar to .91 for the Glasgow Coma Scale. There was no difference in Fleiss's kappa for any of the instruments based on unit size or timing of assessment (earlier or later in the study). For SBS scores, Fleiss's kappa was significantly different in larger and smaller PICUs (.82 vs. .92, p = .003); however, Fleiss's kappa for both groups indicated excellent agreement. CONCLUSION: Monitoring measurement reliability is an essential step in ensuring treatment fidelity and, thus, the validity of study results. Standardization on the use of these core assessment instruments among participating sites was achieved and maintained throughout the trial.

Racial and Ethnic Disparities in Parental Refusal of Consent in a Large, Multisite Pediatric Critical Care Clinical Trial.

OBJECTIVE: To evaluate whether race or ethnicity was independently associated with parental refusal of consent for their child's participation in a multisite pediatric critical care clinical trial. STUDY DESIGN: We performed a secondary analyses of data from Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE), a 31-center cluster randomized trial of sedation management in critically ill children with acute respiratory failure supported on mechanical ventilation. Multivariable logistic regression modeling estimated associations between patient race and ethnicity and parental refusal of study consent. RESULT: Among the 3438 children meeting enrollment criteria and approached for consent, 2954 had documented race/ethnicity of non-Hispanic White (White), non-Hispanic Black (Black), or Hispanic of any race. Inability to approach for consent was more common for parents of Black (19.5%) compared with White (11.7%) or Hispanic children (13.2%). Among those offered consent, parents of Black (29.5%) and Hispanic children (25.9%) more frequently refused consent than parents of White children (18.2%, P < .0167 for each). Compared with parents of White children, parents of Black (OR 2.15, 95% CI 1.56-2.95, P < .001) and Hispanic (OR 1.44, 95% CI 1.10-1.88, P = .01) children were more likely to refuse consent. Parents of children offered participation in the intervention arm were more likely to refuse consent than parents in the control arm (OR 2.15, 95% CI 1.37-3.36, P < .001). CONCLUSIONS: Parents of Black and Hispanic children were less likely to be approached for, and more frequently declined consent for, their child's participation in a multisite critical care clinical trial. Ameliorating this racial disparity may improve the validity and generalizability of study findings. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00814099.

Non-invasive Assessment of Cerebral Blood Flow and Oxygen Metabolism in Neonates during Hypothermic Cardiopulmonary Bypass: Feasibility and Clinical Implications.

The neonatal brain is extremely vulnerable to injury during periods of hypoxia and/or ischemia. Risk of brain injury is increased during neonatal cardiac surgery, where pre-existing hemodynamic instability and metabolic abnormalities are combined with long periods of low cerebral blood flow and/or circulatory arrest. Our understanding of events associated with cerebral hypoxia-ischemia during cardiopulmonary bypass (CPB) remains limited, largely due to inadequate tools to quantify cerebral oxygen delivery and consumption non-invasively and in real-time. This pilot study aims to evaluate cerebral blood flow (CBF) and oxygen metabolism (CMRO2) intraoperatively in neonates by combining two novel non-invasive optical techniques: frequency-domain near-infrared spectroscopy (FD-NIRS) and diffuse correlation spectroscopy (DCS). CBF and CMRO2 were quantified before, during and after deep hypothermic cardiopulmonary bypass (CPB) in nine neonates. Our results show significantly decreased CBF and CMRO2 during hypothermic CPB. More interestingly, a change of coupling between both variables is observed during deep hypothermic CPB in all subjects. Our results are consistent with previous studies using invasive techniques, supporting the concept of FD-NIRS/DCS as a promising technology to monitor cerebral physiology in neonates providing the potential for individual optimization of surgical management.

Disparities by Sexual Orientation in Frequent Engagement in Cancer-Related Risk Behaviors: A 12-Year Follow-Up.

OBJECTIVES: We examined sexual-orientation disparities in frequent engagement in cancer-related risk indicators of tobacco, alcohol, diet and physical activity, ultraviolet radiation, and sexually transmitted infections (STIs). METHODS: We used longitudinal data from the national Growing Up Today Study (1999-2010). Of the analytic sample (n = 9958), 1.8% were lesbian or gay (LG), 1.6% bisexual (BI), 12.1% mostly heterosexual (MH), and 84.5% completely heterosexual (CH). RESULTS: More sexual minorities (LGs, BIs, and MHs) than CHs frequently engaged in multiple cancer-related risk behaviors (33%, 29%, 28%, and 19%, respectively). Sexual-minority young women, especially BI and MH, more frequently engaged over time in substance use and diet and physical activity risk than CH women. More young gay than CH men frequently engaged over time in vomiting for weight control (odds ratio [OR] = 3.2; 95% confidence interval [CI] = 1.1, 9.4), being physically inactive (OR = 1.7; 95% CI = 1.2, 2.4), and using tanning booths (OR = 4.7; 95% CI = 3.0, 7.4), and had a higher prevalence of ever having an STI (OR = 3.5; 95% CI = 2.0, 6.4). Individual analyses were generally comparable to the group-level analyses. CONCLUSIONS: Young sexual minorities are at risk for cancer through frequent exposure to cancer-related risk behaviors over time. Long-term, longitudinal studies and surveillance data are essential and warranted to track frequent engagement in the risk behaviors and cancer-related morbidity and mortality.

Adolescents with tetralogy of Fallot: neuropsychological assessment and structural brain imaging.

BACKGROUND: Few data are available on the neuropsychological, behavioural, or structural brain imaging outcomes in adolescents who underwent corrective surgery in infancy for tetralogy of Fallot. METHODS: In this single-centre cross-sectional study, we enrolled 91 adolescents (13-16 years old) with tetralogy of Fallot and 87 referent subjects. Assessments included tests of academic achievement, memory, executive functions, visual-spatial skills, attention, and social cognition, as well as brain magnetic resonance imaging. RESULTS: Genetic abnormalities or syndromes were present in 25% of tetralogy of Fallot patients, who had markedly greater neuropsychological morbidities than did patients without a syndrome. However, even patients without a syndrome performed significantly worse than the referent group or population norms in all of the neuropsychological domains assessed. In multivariable regression in those without a genetic/phenotypic syndrome, the strongest predictors of adverse late neurodevelopmental outcomes included a greater number of complications at the first operation, more total surgical complications across all operations, and occurrence of post-operative seizures. The presence of at least one abnormality on structural magnetic resonance imaging was more frequent in tetralogy of Fallot patients than the referent group (42% versus 8%). CONCLUSIONS: Adolescents with tetralogy of Fallot are at increased neurodevelopmental risk and would benefit from ongoing surveillance and educational supports even after childhood.

Sexual-orientation disparities in substance use in emerging adults: a function of stress and attachment paradigms.

More lesbian, gay, and bisexual (LGB) youths than heterosexuals report substance use. We examined a theoretical model to understand these disparities in lifetime and past-year substance use by means of stress and attachment paradigms, using the longitudinal Growing Up Today Study (GUTS) and Nurses' Health Study II (NHSII). GUTS participants are the children of participants in NHSII; thus, child and maternal data are available. In addition, GUTS contains siblings, allowing for comparisons of LGB and heterosexual siblings. Of 5,647 GUTS youths (M = 20.6 years old in 2005), 1.6% were lesbian/gay (LG), 1.6% bisexual (BI), 9.9% mostly heterosexual (MH), and 86.9% completely heterosexual (CH). After adjusting for sibling clustering in GUTS and covariates, significantly more sexual minorities (LGs, BIs, and MHs) than CHs reported lifetime and past-year smoking, nonmarijuana illicit drug use, and prescription drug misuse. More sexual minorities also reported marijuana use in the past year. The relations between sexual orientation and substance use were moderated by the stress markers: As mother's discomfort with homosexuality increased, more BIs and MHs than CHs used substances. As childhood gender nonconforming behaviors increased, more LGs than CHs used substances. The relations between sexual orientation and substance use were mediated by attachment and maternal affection (percent of effect mediated ranged from 5.6% to 16.8%% for lifetime substance use and 4.9% to 24.5% for past-year use). In addition, sibling comparisons found that sexual minorities reported more substance use, more childhood gender nonconforming behaviors, and less secure attachment than CH siblings; mothers reported less affection for their sexual minority than CH offspring. The findings indicate the importance of stress and attachment paradigms for understanding sexual-orientation disparities in substance use.

Disparities in depressive distress by sexual orientation in emerging adults: the roles of attachment and stress paradigms.

Lesbian, gay, and bisexual (BI) youth have elevated rates of depression compared to heterosexuals. We proposed and examined a theoretical model to understand whether attachment and stress paradigms explain disparities in depressive distress by sexual orientation, using the longitudinal Growing Up Today Study (GUTS) and Nurses' Health Study II (NHSII). GUTS participants eligible for this analysis reported sexual orientation, childhood gender nonconforming behaviors (GNBs), attachment to mother (all in 2005), and depressive symptoms (in 2007). Mothers of the GUTS participants who are the NHSII participants reported attitudes toward homosexuality (in 2004) and maternal affection (in 2006). The sample had 6,122 participants. Of GUTS youth (M = 20.6 years old in 2005; 64.4 % female), 1.7 % were lesbian/gay (LG), 1.7 % bisexual (BI), 10.0 % mostly heterosexual (MH), and 86.7 % completely heterosexual (CH). After adjusting for demographic characteristics and sibling clustering, LGs, BIs, and MHs reported more depressive distress than CHs. This relation was partially mediated (i.e., explained) for LGs, BIs, and MHs relative to CHs by less secure attachment. A conditional relation (i.e., interaction) indicated that BIs reported more distress than CHs as GNBs increased for BIs; no comparable relation was found for LGs versus CHs. Sibling comparisons found that sexual minorities (LGs, BIs, and MHs) reported more depressive distress, less secure attachment, and more childhood GNBs than CH siblings; the mothers reported less affection for their sexual-minority than CH offspring. The findings suggest that attachment and childhood gender nonconformity differentially pattern depressive distress by sexual orientation. Attachment and related experiences are more problematic for sexual minorities than for their CH siblings.

Sexual-orientation disparities in cigarette smoking in a longitudinal cohort study of adolescents.

INTRODUCTION: Youths with a minority sexual orientation (i.e., gay, lesbian, bisexual, and mostly heterosexual) are at high risk for cigarette smoking. We examined sexual-orientation disparities in smoking during adolescence and emerging adulthood and investigated the role of age at first smoking in contributing to smoking disparities. METHODS: We used data from the Growing Up Today Study, a large longitudinal cohort of adolescents followed from ages 12 to 24 years (N = 13,913). Self-administered questionnaires filled out annually or biennially assessed age at first smoking, current smoking, frequency of smoking, number of cigarettes smoked daily, and nicotine dependence. Proportional hazards survival analysis and repeated measures regression estimated sexual-orientation differences in smoking. RESULTS: Compared with completely heterosexuals, lesbian/gay, bisexual, and mostly heterosexual youths smoked their first cigarette at younger ages, were more likely to be current smokers, and had higher frequency of smoking. Among past-year smokers, sexual-minority females smoked more cigarettes daily and scored higher on nicotine dependence than completely heterosexual females. In some instances, gender and age modified relationships between sexual orientation and smoking, with relative risk accentuated in female sexual minorities and in sexual minorities during younger ages. Younger age of smoking onset contributed to elevated smoking in mostly heterosexuals and bisexuals, and to a lesser extent in lesbians, but not in gay males. CONCLUSIONS: Sexual-orientation minorities are at greater risk for smoking during adolescence and emerging adulthood than heterosexuals. Disparities are larger in females and evident in early adolescence. Prevention and cessation efforts should target this population, preferably beginning in early adolescence.

Validity and generalizability of the Withdrawal Assessment Tool-1 (WAT-1) for monitoring iatrogenic withdrawal syndrome in pediatric patients.

Critically ill pediatric patients frequently receive prolonged analgesia and sedation to provide pain relief and facilitate intensive care therapies. Iatrogenic withdrawal syndrome occurs when these drugs are stopped abruptly or weaned too rapidly. We investigated the validity and generalizability of the Withdrawal Assessment Tool-1 (WAT-1) in children during weaning of analgesics and sedatives. Of 308 children initially supported on mechanical ventilation for acute respiratory failure, 126 (41%) from 21 centers (median age 1.6 years; interquartile range 0.6-7.7 years) were exposed to 5 or more days of opioids. Subjects were assessed for withdrawal symptoms with the WAT-1, an 11-item (12-point) scale, from the first day of weaning from analgesia/sedation until 72 h after the last opioid dose. A total of 836 daily WAT-1 assessments were completed, with a median (interquartile range) WAT-1 score of 2 (0-4) over 6 (3-9) days per subject. There were no significant differences in WAT-1 scores as a function of age. Factor analyses confirmed that motor-related symptoms and behavioral state accounted for the most variance in WAT-1 scores. Supporting construct validity, cumulative opioid exposures were greater [40.2 (19.7-83.4) vs 17.6 (14.6-39.7) mg/kg, P=.004], length of opioid treatment before weaning was longer [7 (6-11) vs 5 (5-8)days, P=.004], and length of weaning from opioids was longer [10 (6-14) vs 6 (3-9)days, P=.008] in subjects with WAT-1 scores of ≥ 3 compared to subjects with WAT-1 scores of <3. The WAT-1 shows good psychometric performance and generalizability when used to assess clinically important withdrawal symptoms in pediatric intensive care and general ward settings.

Adolescents with d-transposition of the great arteries corrected with the arterial switch procedure: neuropsychological assessment and structural brain imaging.

BACKGROUND: We report neuropsychological and structural brain imaging assessments in children 16 years of age with d-transposition of the great arteries who underwent the arterial switch operation as infants. Children were randomly assigned to a vital organ support method, deep hypothermia with either total circulatory arrest or continuous low-flow cardiopulmonary bypass. METHODS AND RESULTS: Of 159 eligible adolescents, 139 (87%) participated. Academic achievement, memory, executive functions, visual-spatial skills, attention, and social cognition were assessed. Few significant treatment group differences were found. The occurrence of seizures in the postoperative period was the medical variable most consistently related to worse outcomes. The scores of both treatment groups tended to be lower than those of the test normative populations, with substantial proportions scoring ≥1 SDs below the expected mean. Although the test scores of most adolescents in this trial cohort are in the average range, a substantial proportion have received remedial academic or behavioral services (65%). Magnetic resonance imaging abnormalities were more frequent in the d-transposition of the great arteries group (33%) than in a referent group (4%). CONCLUSIONS: Adolescents with d-transposition of the great arteries who have undergone the arterial switch operation are at increased neurodevelopmental risk. These data suggest that children with congenital heart disease may benefit from ongoing surveillance to identify emerging difficulties. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000470.

Neuropsychological function in school-age children with low mercury exposures.

The EPA reference dose for methylmercury (MeHg) was established using data from populations with greater exposures than those typical of the US. Few data are available on potential adverse health effects at lower levels. We examined relationships between hair mercury (Hg) levels and neuropsychological outcomes in a population of US children. This study included data from 355 children ages 6-10 enrolled in the New England Children's Amalgam Trial. Data on total hair Hg levels, sociodemographic information and neuropsychological function were collected. We evaluated associations between hair Hg and neuropsychological test scores with linear regression methods and used generalized additive models to determine the shape of associations that departed from linearity. Models controlled for relevant covariates, including the potential beneficial effects of consuming fish. In adjusted models, we observed no significant linear relationships between hair Hg level and any test score. Significant departures from linearity were identified for WIAT Math Reasoning and WRAMVA Visual-Motor Composite scores. The association was positive for hair Hg levels below 0.5 microg/g and negative for levels between 0.5 and 1.0 microg/g. Overall, test scores of children with hair Hg levels 1.0 microg/g appeared to be lower than those of children with levels < 1.0 microg/g, but few children had levels in this upper range and these differences did not reach statistical significance. Hair Hg levels below 1.0 microg/g in US school-age children were not adversely related to neuropsychological function.

Sexual orientation disparities in longitudinal alcohol use patterns among adolescents: findings from the Growing Up Today Study.

OBJECTIVE: To compare sexual orientation group differences in the longitudinal development of alcohol use behaviors during adolescence. DESIGN: Community-based prospective cohort study. SETTING: Self-reported questionnaires. PARTICIPANTS: A total of 13,450 Growing Up Today Study participants (79.7% of the original cohort) aged 9 to 14 years at baseline in 1996 were followed up for more than 7 years. Main Exposure Self-reported sexual orientation classified as heterosexual, mostly heterosexual, bisexual, or gay/lesbian. MAIN OUTCOME MEASURES: Age at alcohol use initiation, any past-month drinking, number of alcoholic drinks usually consumed, and number of binge drinking episodes in the past year. RESULTS: Compared with heterosexual participants, youth reporting any minority sexual orientation reported having initiated alcohol use at younger ages. Greater risk of alcohol use was consistently observed for mostly heterosexual males and females and for bisexual females, whereas gay and bisexual males and lesbians reported elevated levels of alcohol use on only some indicators. Gender was an important modifier of alcohol use risk; mostly heterosexual and bisexual females exhibited the highest relative risk. Younger age at alcohol use initiation among participants with minority sexual orientations significantly contributed to their elevated risk of binge drinking. CONCLUSIONS: Our findings suggest that disparities in alcohol use among youth with a minority sexual orientation emerge in early adolescence and persist into young adulthood. Health care providers should be aware that adolescents with a minority sexual orientation are at greater risk of alcohol use.

Relationship between funding source and conclusion among nutrition-related scientific articles.

BACKGROUND: Industrial support of biomedical research may bias scientific conclusions, as demonstrated by recent analyses of pharmaceutical studies. However, this issue has not been systematically examined in the area of nutrition research. The purpose of this study is to characterize financial sponsorship of scientific articles addressing the health effects of three commonly consumed beverages, and to determine how sponsorship affects published conclusions. METHODS AND FINDINGS: Medline searches of worldwide literature were used to identify three article types (interventional studies, observational studies, and scientific reviews) about soft drinks, juice, and milk published between 1 January, 1999 and 31 December, 2003. Financial sponsorship and article conclusions were classified by independent groups of coinvestigators. The relationship between sponsorship and conclusions was explored by exact tests and regression analyses, controlling for covariates. 206 articles were included in the study, of which 111 declared financial sponsorship. Of these, 22% had all industry funding, 47% had no industry funding, and 32% had mixed funding. Funding source was significantly related to conclusions when considering all article types (p = 0.037). For interventional studies, the proportion with unfavorable conclusions was 0% for all industry funding versus 37% for no industry funding (p = 0.009). The odds ratio of a favorable versus unfavorable conclusion was 7.61 (95% confidence interval 1.27 to 45.73), comparing articles with all industry funding to no industry funding. CONCLUSIONS: Industry funding of nutrition-related scientific articles may bias conclusions in favor of sponsors' products, with potentially significant implications for public health.

Problems in exposure assessment of fluoride in drinking water.

OBJECTIVES: We developed a source documentation approach that identified fluoride content of drinking water at the state or local level to estimate fluoride concentrations from public water systems. We then compared estimates from this approach with estimates obtained from a single source, the 1992 Centers for Disease Control and Prevention (CDC) Fluoridation Census. METHODS: We used residential histories from a case-control study. For each residence we attempted to determine fluoride concentrations using the 1992 CDC Fluoridation Census. For the source documentation method we utilized multiple sources from state and local contacts to verify and collect additional data. We compared the fluoride estimates obtained by the two methods. RESULTS: When fluoride values were found using both methods, there was good correlation (Kendall's tau = 0.85; 95% confidence interval = 0.79, 0.90) and concordance was 96 percent. We obtained over 99 percent of the fluoride values needed using source documentation as compared to 49 percent of the values needed when we used a single publication. When fluoride values were missing using the 1992 CDC Fluoridation Census, 21 percent had source documentation estimates of at least 0.7 ppm. CONCLUSIONS: Researchers need to consider limitations of using a secondary data source to estimate fluoride in drinking water, particularly in studies where exposure to fluoride is the primary exposure of interest.