Prenatal Exposure to Organophosphorous Pesticides and Fetal Growth: Pooled Results from Four Longitudinal Birth Cohort Studies.

BACKGROUND: Organophosphorous (OP) pesticides are associated with reduced fetal growth in animals, but human studies are inconsistent. OBJECTIVES: We pooled data from four cohorts to examine associations of prenatal OP exposure with birth weight (n = 1,169), length (n = 1,152), and head circumference (n = 1,143). METHODS: Data were from the CHAMACOS, HOME, Columbia, and Mount Sinai birth cohorts. Concentrations of three diethyl phosphate (ΣDEP) and three dimethyl phosphate (ΣDMP) metabolites of OP pesticides [summed to six dialkyl phosphates (ΣDAPs)] were measured in maternal urine. Linear regression and mixed-effects models were used to examine associations with birth outcomes. RESULTS: We found no significant associations of ΣDEP, ΣDMP, or ΣDAPs with birth weight, length, or head circumference overall. However, among non-Hispanic black women, increasing urinary ΣDAP and ΣDMP concentrations were associated with decreased birth length (ß = -0.4 cm; 95% CI: -0.9, 0.0 and ß = -0.4 cm; 95% CI: -0.8, 0.0, respectively, for each 10-fold increase in metabolite concentration). Among infants with the PON1192RR genotype, ΣDAP and ΣDMP were negatively associated with length (ß = -0.4 cm; 95% CI: -0.9, 0.0 and ß = -0.5 cm; 95% CI: -0.9, -0.1). CONCLUSIONS: This study confirms previously reported associations of prenatal OP exposure among black women with decreased infant size at birth, but finds no evidence of smaller birth weight, length, or head circumference among whites or Hispanics. Contrary to our hypothesis, we found stronger inverse associations of DAPs and birth outcome in infants with the less susceptible PON1192RR genotype. The large pooled data set facilitated exploration of interactions by race/ethnicity and PON1 genotype, but was limited by differences in study populations. CITATION: Harley KG, Engel SM, Vedar MG, Eskenazi B, Whyatt RM, Lanphear BP, Bradman A, Rauh VA, Yolton K, Hornung RW, Wetmur JG, Chen J, Holland NT, Barr DB, Perera FP, Wolff MS. 2016. Prenatal exposure to organophosphorous pesticides and fetal growth: pooled results from four longitudinal birth cohort studies. Environ Health Perspect 124:1084-1092; http://dx.doi.org/10.1289/ehp.1409362.

Uncertainties in estimating health risks associated with exposure to ionising radiation.

The information for the present discussion on the uncertainties associated with estimation of radiation risks and probability of disease causation was assembled for the recently published NCRP Report No. 171 on this topic. This memorandum provides a timely overview of the topic, given that quantitative uncertainty analysis is the state of the art in health risk assessment and given its potential importance to developments in radiation protection. Over the past decade the increasing volume of epidemiology data and the supporting radiobiology findings have aided in the reduction of uncertainty in the risk estimates derived. However, it is equally apparent that there remain significant uncertainties related to dose assessment, low dose and low dose-rate extrapolation approaches (e.g. the selection of an appropriate dose and dose-rate effectiveness factor), the biological effectiveness where considerations of the health effects of high-LET and lower-energy low-LET radiations are required and the transfer of risks from a population for which health effects data are available to one for which such data are not available. The impact of radiation on human health has focused in recent years on cancer, although there has been a decided increase in the data for noncancer effects together with more reliable estimates of the risk following radiation exposure, even at relatively low doses (notably for cataracts and cardiovascular disease). New approaches for the estimation of hereditary risk have been developed with the use of human data whenever feasible, although the current estimates of heritable radiation effects still are based on mouse data because of an absence of effects in human studies. Uncertainties associated with estimation of these different types of health effects are discussed in a qualitative and semi-quantitative manner as appropriate. The way forward would seem to require additional epidemiological studies, especially studies of low dose and low dose-rate occupational and perhaps environmental exposures and for exposures to x rays and high-LET radiations used in medicine. The development of models for more reliably combining the epidemiology data with experimental laboratory animal and cellular data can enhance the overall risk assessment approach by providing biologically refined data to strengthen the estimation of effects at low doses as opposed to the sole use of mathematical models of epidemiological data that are primarily driven by medium/high doses. NASA's approach to radiation protection for astronauts, although a unique occupational group, indicates the possible applicability of estimates of risk and their uncertainty in a broader context for developing recommendations on: (1) dose limits for occupational exposure and exposure of members of the public; (2) criteria to limit exposures of workers and members of the public to radon and its short-lived decay products; and (3) the dosimetric quantity (effective dose) used in radiation protection.

Can the reduction of pediatric injury rates be sustained using a community-based approach?

BACKGROUND: Injuries are the leading cause of morbidity and mortality in US residents aged 1 to 44 years. Community-based interventions are effective in reducing injuries. Using this approach, investigators significantly reduced injuries in Avondale, Ohio, between 1999 and 2004 compared with three control communities (42 vs. 15%, respectively). The objective of this study was to determine if injury reduction was sustained through the 5 years after initial implementation of injury prevention (IP) efforts in Avondale compared with the same three control communities. DESIGN/METHODS: Injury prevention interventions implemented in Avondale, Ohio, during previous study years were sustained. Two new playgrounds were built, but no other new interventions were introduced. Control communities had no programs introduced by the team during the study period. Data were obtained from the Hamilton County Injury Surveillance System from 2005 to 2009 for deaths, hospitalizations, and emergency department visits due to injury for children 0 to 19 years old. Data from the study community were compared with those of the same three control communities as in our previous work, with similar demographics and socioeconomic characteristics, as well as with data obtained previously from 1999 to 2004. Census data based on annual estimates were used to calculate injury rates. RESULTS: The injury rate in Avondale decreased from 17,073 to 11,284 injuries per 100,000 children per year during the 11-year period (33.9% reduction). The injury rate in the control communities decreased from 14,436 to 12,381 injuries per 100,000 children per year in the same period (14.2% reduction). The difference in the injury rate decrease between the intervention and control communities was statistically significant, p < 0.001. From 2005 to 2009, the lower injury rate was sustained in Avondale, p = 0.58. CONCLUSIONS: Community-based strategies to prevent injuries to children in high-risk communities can be successful in reducing overall injury rates. These efforts can result in sustained injury reduction over time despite no new interventions being introduced.

Mortality and ionising radiation exposures among workers employed at the Fernald Feed Materials Production Center (1951-1985).

OBJECTIVES: To examine mortality patterns and dose-response relations between ionising radiation and mortality outcomes of a priori interest in 6409 uranium workers employed for at least 30 days (1951-1985), and followed through 2004. METHODS: Cohort mortality was evaluated through standardised mortality ratios (SMR). Linear excess relative risk (ERR) regression models examined associations between cause-specific mortality and exposures to internal ionising radiation from uranium deposition, external gamma and x-ray radiation, and radon decay products, while adjusting for non-radiologic covariates. RESULTS: Person-years at risk totalled 236 568 (mean follow-up 37 years), and 43% of the cohort had died. All-cause mortality was below expectation only in salaried workers. Cancer mortality was significantly elevated in hourly males, primarily from excess lung cancer (SMR=1.25, 95% CI 1.09 to 1.42). Cancer mortality in salaried males was near expectation, but lymphohaematopoietic malignancies were significantly elevated (SMR=1.52, 95% CI 1.06 to 2.12). A positive dose-response relation was observed for intestinal cancer, with a significant elevation in the highest internal organ dose category and a significant dose-response with organ dose from internal uranium deposition (ERR=1.5 per 100 µGy, 95% CI 0.12 to 4.1). CONCLUSIONS: A healthy worker effect was observed only in salaried workers. Hourly workers had excess cancer mortality compared with the US population, although there was little evidence of a dose-response trend for any cancer evaluated except intestinal cancer. The association between non-malignant respiratory disease and radiation dose observed in previous studies was not apparent, possibly due to improved exposure assessment, different outcome groupings, and extended follow-up.

Effects of HEPA air cleaners on unscheduled asthma visits and asthma symptoms for children exposed to secondhand tobacco smoke.

OBJECTIVE: The goal was to test the effects of high-efficiency, particulate-arresting (HEPA) air cleaners on unscheduled asthma visits and symptoms among children with asthma exposed to secondhand smoke. METHODS: We enrolled 225 eligible children who were 6 to 12 years of age, had physician-diagnosed asthma, and were exposed to ≥5 cigarettes per day. We conducted a double-blind, randomized trial. Children were assigned randomly to receive 2 active or inactive HEPA air cleaners. RESULTS: Of 225 enrolled children, 110 (49%) were assigned to the intervention group and 115 (51%) to the control group; 215 (95%) completed the trial. During the trial, there were 42 fewer unscheduled asthma visits among children in the intervention group (18.5% [95% confidence interval: 1.25%-82.75%]; P = .043), compared with those in the control group, after adjustment for baseline differences. There was a significant difference in the reductions of levels of particles of >0.3 µm according to group assignment; there was a 25% reduction in particle levels in the intervention group, compared with a 5% reduction in the control group (P = .026). There were no significant differences in parent-reported asthma symptoms, exhaled nitric-oxide levels, air nicotine levels, or cotinine levels according to group assignment. CONCLUSIONS: These results hold promise for using HEPA air cleaners as part of a multifaceted strategy to reduce asthma morbidity, but further research is necessary before they can be recommended routinely for the medical management of asthma.

Determinants of serum cotinine and hair cotinine as biomarkers of childhood secondhand smoke exposure.

Understanding the determinants of childhood secondhand smoke (SHS) exposure is important in measuring and preventing exposure to this widespread environmental contaminant. We evaluated the ability of a broad set of factors to explain variability in serum cotinine, reflecting recent exposure, and hair cotinine, reflecting longer-term exposure. We included repeated measures from 223 elementary-school-age asthmatic children residing with a smoker. We used a manual model-building approach and likelihood ratio tests to select a model predicting each biomarker, and also compared the predictive ability of determinants using Akaike Information Criteria. Potential determinants included a comprehensive parent questionnaire, household nicotine, home ventilation characteristics, exposure in vehicles and others' homes, child demographics, and family social class. Variables in each of these categories remained in the final model for both serum (R(2) of 0.61) and hair cotinine (R(2) of 0.45). A comprehensive set of factors was required to best predict cotinine. Studies should use biomarkers for the best quantitative assessment of SHS exposure. Hair cotinine may be a problematic measure because it was highly influenced by racial differences that were unexplained by SHS exposure. When biospecimen collection is not possible, a household nicotine measurement is warranted. If only questionnaires are available, multiple questions are required to best characterize exposure, such as number of cigarettes, hours spent in a room with concurrent smoking, maternal smoking, and approximate home size.

Mortality from lymphohematopoietic malignancies and brain cancer among embalmers exposed to formaldehyde.

BACKGROUND: Excess mortality from lymphohematopoietic malignancies, in particular myeloid leukemia, and brain cancer has been found in surveys of anatomists, pathologists, and funeral industry workers, all of whom may have worked with formaldehyde. We investigated the relation of mortality to work practices and formaldehyde exposure levels among these professionals to address cancer risk in the funeral industry. METHODS: Professionals employed in the funeral industry who died between January 1, 1960, and January 1, 1986, from lymphohematopoietic malignancies (n = 168) or brain tumors (n = 48) (ie, case subjects) were compared with deceased matched control subjects (n = 265) with regard to lifetime work practices and exposures in the funeral industry, which were obtained by interviews with next of kin and coworkers, and to estimated levels of formaldehyde exposure. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by use of logistic regression. All statistical tests were two-sided. RESULTS: Mortality from myeloid leukemia increased statistically significantly with increasing number of years of embalming (P for trend = .020) and with increasing peak formaldehyde exposure (P for trend = .036). Compared with subjects who performed fewer than 500 lifetime embalmings, mortality from myeloid leukemia was elevated among those who performed embalmings for more than 34 years (OR = 3.9, 95% CI = 1.2 to 12.5, P = .024), who performed more than 3068 embalmings (OR = 3.0, 95% CI = 1.0 to 9.2, P = .057), and those whose estimated cumulative formaldehyde exposure exceeded 9253 parts per million-hours (OR = 3.1; 95% CI = 1.0 to 9.6, P = .047). These exposures were not related to other lymphohematopoietic malignancies or to brain cancer. CONCLUSION: Duration of embalming practice and related formaldehyde exposures in the funeral industry were associated with statistically significantly increased risk for mortality from myeloid leukemia.

Environmental exposures, nitric oxide synthase genes, and exhaled nitric oxide in asthmatic children.

Exhaled nitric oxide (FeNO), a measure of airway inflammation, is being explored as a tool to guide asthma management in children. Investigators have identified associations of genetic polymorphisms in nitric oxide synthase genes (NOS1 and NOS3) with FeNO levels; however, none have explored whether these polymorphisms modify the relationship of environmental exposures with FeNO. The objective of this project was to evaluate the association of NOS polymorphisms and environmental exposures with FeNO levels among children with asthma. We conducted a 12-month prospective cohort study of 225 tobacco-smoke exposed children (6-12 years) with doctor-diagnosed asthma. We assessed environmental exposures (tobacco, indoor allergens, & airborne particulates), polymorphisms in NOS1 (an intronic AAT tandem repeat) and NOS3 (G894T), and FeNO levels. There was no association of NOS1 or NOS3 polymorphisms with FeNO levels. There were no significant interactions of environmental exposures and the NOS1 polymorphism with FeNO levels. In contrast, there was an interaction of the NOS3 polymorphism and airborne nicotine concentration with FeNO levels (P = 0.01). Among GG genotype individuals, nicotine exposure did not affect FeNO levels; however, among individuals with at least one T allele, higher nicotine exposure was associated with lower FeNO levels (approximately 5 ppb decrease from the lowest to the highest quartile). We conclude that genetic differences may explain some of the conflicting results in studies of the effects of tobacco smoke exposure on FeNO levels and may make FeNO interpretation difficult for a subset of children with asthma.

Views of treatment decision making from adolescents with chronic illnesses and their parents: a pilot study.

OBJECTIVE: Shared decision making may increase satisfaction with health care and improve outcomes, but little is known about adolescents' decision-making preferences. The primary purpose of this study is to describe the decision-making preferences of adolescents with chronic illnesses and their parents, and the extent to which they agree. DESIGN: Survey. SETTING AND PARTICIPANTS: Participants were 82 adolescents seen at one of four paediatric chronic illness subspecialty clinics and 62 of their parents. MAIN VARIABLES: Predictor variables include sociodemographics, health parameters, risk behaviour, and physical and cognitive development. The main outcome variable is preferences for decision-making style. RESULTS AND CONCLUSIONS: When collapsed into three response categories, nearly equal percentages of adolescents (37%) and parents (36%) preferred shared decision making. Overall, the largest proportion of adolescents (46%) and parents (53%) preferred passive decision making compared to active or shared decision making. Across five response choices, 33% of pairs agreed. Agreement was slight and not significant. Improved general health perceptions (OR=0.76, 95% CI=0.59-0.99) and improved behaviour (OR=0.75, 95% CI=0.56-0.99) were significantly associated with parents' preferences for less active decision making. Older age was significantly associated with agreement (OR 1.58, 95% CI=1.09-2.30) between parents and adolescents. The paucity of significant predictor variables may indicate physicians need to inquire directly about patient and parent preferences.

Seasonal variation and environmental predictors of exhaled nitric oxide in children with asthma.

The fraction of exhaled nitric oxide (FeNO), a measure of airway inflammation, shows promise as a noninvasive tool to guide asthma management, but there is a paucity of longitudinal data about seasonal variation and environmental predictors of FeNO in children. The objective of this project was to evaluate how environmental factors affect FeNO concentrations over a 12-month study period among children with doctor diagnosed asthma. We conducted a prospective cohort study of 225 tobacco-smoke exposed children age 6-12 years with doctor-diagnosed asthma including measures of FeNO, medication use, settled indoor allergens (dust mite, cat, dog, and cockroach), and tobacco smoke exposure. Baseline geometric mean FeNO was 12.4 ppb (range 1.9-60.9 ppb). In multivariable analyses, higher baseline FeNO levels, atopy, and fall season were associated with increased FeNO levels, measured 6 and 12 months after study initiation, whereas inhaled steroid use, summer season, and increasing nicotine exposure were associated with lower FeNO levels. In secondary analyses of allergen sensitization, only sensitization to dust mite and cat were associated with increased FeNO levels. Our data demonstrate that FeNO levels over a year long period reflected baseline FeNO levels, allergen sensitization, season, and inhaled steroid use in children with asthma. These results indicate that FeNO levels are responsive to common environmental triggers as well as therapy for asthma in children. Clinicians and researchers may need to consider an individual's baseline FeNO levels to manage children with asthma.

The conundrum of unmeasured confounding: Comment on: "Can some of the detrimental neurodevelopmental effects attributed to lead be due to pesticides? by Brian Gulson".

The problem described by Dr. Brian Gulson - confounding by unmeasured exposures to pesticides - is only the most recent in a series of potential confounders cited to explain the observed effect of lead on children's intellectual abilities or behavioral problems. Despite the persistent problem of unmeasured confounders, there are several lines of evidence implicating lead as a toxicant at blood lead levels <10 microg/dL. First, in striking contrast with pesticides, there is considerable evidence from numerous studies linking low-level lead exposure with cognitive deficits and behavioral problems, even after controlling for a variety of potential confounders. Second, the consistency of evidence from diverse cohorts and distinct, if not always directly measured potential confounders - enhances our confidence that the lead effect observed at blood lead levels <10 microg/dL is not attributable to unmeasured confounders. Third, in our reanalysis of the Rochester Lead Study, the inclusion of parent-reported mouthing behaviors and breastfeeding status did not attenuate the effect of lead exposure on children's intellectual function. Finally, although we can never entirely dismiss unmeasured confounding in observational studies, we can rely on experimental studies of lead-exposed animals to confirm that lead is a toxicant. Thus, while we must remain vigilant for unmeasured or poorly measured confounders, it is crucial to balance the endless search for confounders with the evidence of toxicity and the need to take action to protect public health. The alternative, to perpetually permit children to be exposed to lead and other emerging toxicants, is both absurd and unacceptable.

Estimation of radon exposures to workers at the Fernald Feed Materials Production Center 1952-1988.

The Feed Materials Production Center (FMPC) at Fernald, Ohio produced uranium metal products for use in Department of Energy defense programs. Radium-contaminated waste material was stored on-site in two K-65 silos on the west side of the facility and provided a source of 222Ra. The initial objective of this study was to estimate radon exposures to employees at FMPC working from 1952 to 1988. A modified Gaussian plume model was used to estimate exposures to workers. In an effort to validate these model-based estimates, we used 138 CR-39 film assays from window glass sampled in buildings throughout the site. Results from the CR-39 assays indicated a second substantial source of radon, the smaller Q-11 silos located in the production area. A response-surface regression analysis using a cubic spline model was fit to the CR-39 data to estimate 210Po surface activity levels at geographic coordinates throughout the facility. Knowledge of the age of the glass, the amount of contaminated waste in the Q-11 silos, and 210Po decay rates were used to estimate annual exposures to radon decay products (WLM: working level months). Estimated WLM levels associated with the Q-11 source term indicated that employees working in the vicinity during the period when they were filled with radium-contaminated waste (1952-1958) received substantially higher radon exposures than those from the K-65 source during this period. Results of the two models, corresponding to the K-65 and Q-11 sources, were combined to estimate WLM levels by year for each of the 7143 Fernald workers during the period 1952-1988. Estimated cumulative exposures to individual workers ranged from <0.5 to 751 WLM. Estimated radon exposures from this newly discovered source have important implications for future epidemiologic studies of lung cancer in workers at the Fernald facility.

Specialists understanding of the health care preferences of chronically ill adolescents.

PURPOSE: Doctors must understand patients' priorities to create an effective treatment partnership. Little is known about whether subspecialist pediatricians understand chronically ill adolescents' preferences. METHODS: A survey was conducted of 155 adolescents with chronic illnesses and 52 subspecialty physicians recruited from the same clinics of a children's hospital. Adolescents and physicians rated the importance that adolescents place on items relating to quality of care and physician-patient communication styles using a previously validated measure. RESULTS: For quality of care items, rank order correlation between physicians and patient responses was high (r = .63, p < .001) and both rated pain management items as most important. Physicians underestimated the importance adolescents placed on communicating with the physician as a friend and medical-technical aspects of care. For communication items, physicians' responses were significantly different than adolescents for 13 of 17 items. Except for three items pertaining to autonomy, physician and patient responses were in the same direction, but adolescent responses were less extreme. CONCLUSIONS: Physicians understood the importance of pain management to adolescents with chronic illnesses, but overestimated their desired level of autonomy. Asking adolescents for their preferences may be the first step in improving adolescents' experience of care.

Health care preferences and priorities of adolescents with chronic illnesses.

BACKGROUND: Efforts to make health care for adolescents with chronic illnesses more patient-centered must be grounded in an understanding and clear measures of adolescents' preferences and priorities. OBJECTIVE: To develop a measure of health care preferences of adolescents with chronic illnesses and to determine demographic, developmental, and health factors associated with adolescents' preferences. DESIGN: Mixed-method questionnaire development and survey. SETTING: Subspecialty clinics of a tertiary care children's hospital. PARTICIPANTS: All adolescents (age: 11-19 years) with juvenile rheumatoid arthritis, sickle cell disease, inflammatory bowel disease, or cystic fibrosis of at least 2-year duration who were being treated at the participating center were eligible to participate, and 155 of 251 did so (62%). The participants had a mean age of 15.5 +/- 2.4 years, 45% were male, and 75% were white. INTERVENTION: None. MAIN OUTCOME MEASURES: Ratings of 65 items related to quality of care and 17 items related to physician-patient communication styles. RESULTS: An 82-item questionnaire, devised from qualitative analysis of focus group results, contained 65 Likert scale items that adolescents considered important for health care quality and 17 forced-choice items related to adolescents' preferences for communication. Among the first 65 items, the group of questions related to physician trust and respect had the highest rating of 5.24 +/- 0.62 of 6, followed by patient power and control (mean rating: 4.72 +/- 0.77) and then caring and closeness in the patient-doctor relationship (mean rating: 4.19 +/- 0.91). For the communication items, the adolescents, on average, preferred communication directly to them rather than to their parents and were nearly neutral regarding physicians' inquiries about personal issues. CONCLUSIONS: Participants rated aspects of interpersonal care (especially honesty, attention to pain, and items related to respect) as most important in their judgments of quality. As in most previous studies of adults, technical aspects of care were also rated highly, suggesting that adolescents understand and value both scientific and interpersonal aspects of care.

Determination of risk factors for Epstein-Barr virus-associated posttransplant lymphoproliferative disorder in pediatric liver transplant recipients using objective case ascertainment.

BACKGROUND: Previous studies have suggested an increased risk of Epstein-Barr virus-associated posttransplant lymphoproliferative disorder (EBV-PTLD) in patients receiving tacrolimus for immunosuppression. We hypothesized that after correction for confounding variables, immunosuppression with tacrolimus is not associated with an increased risk of EBV-PTLD. METHODS: Potential cases of EBV-PTLD, identified by chart review, were independently ascertained by three clinicians and defined using published criteria. Agreement in diagnosing EBV-PTLD was measured using Kappa coefficients. Unadjusted and adjusted relative risk estimates were determined using proportional hazards regression. RESULTS: Twenty-three cases of EBV-PTLD were identified in 221 patients, a proportion of 10.4% (95% confidence interval [CI]: 6.4%-14.4%). Multivariable analysis revealed that immunosuppression with tacrolimus was associated with an increased risk of EBV-PTLD (relative risk 3.10: 95% CI: 1.21-7.92), as was age at transplantation as a continuous variable (parameter estimate -0.15, P=0.03). Kappa coefficients in diagnosing EBV-PTLD and subclassifying as neoplastic and non-neoplastic EBV-PTLD were 0.73 (95% CI: 0.54-0.93) and 0.54 (95% CI: 0.40-0.68), respectively. Patients with neoplastic PTLD demonstrated a lower probability of survival than patients with non-neoplastic PTLD and non-cases. CONCLUSIONS: Immunosuppression with tacrolimus and young age at transplantation are associated with an increased risk of EBV-PTLD in children undergoing liver transplantation, although we cannot exclude detection bias as an explanation for this observed increase. Good agreement between observers can be achieved using previously published criteria for defining EBV-PTLD. Patients with neoplastic EBV-PTLD may have a worse prognosis, and thus identification of risk factors for the development of this subtype of the disorder may be more important.

Impact of recent pulmonary exacerbations on quality of life in patients with cystic fibrosis.

OBJECTIVE: To compare the health-related quality of life (HRQOL) of people with cystic fibrosis (CF) to the general population, and to determine the relationship between HRQOL and clinical and demographic factors. DESIGN: Cross-sectional analysis of observational cohort. SETTING: Outpatient clinics of a Midwestern CF center. SUBJECTS: One hundred sixty-two subjects with CF aged 5 to 45 years. MAIN OUTCOME MEASURES: Physical and psychosocial summary scores and individual scale scores for the Child Health Questionnaire and Short Form-36. RESULTS: Compared with the general population, people with CF reported similar scores for most psychosocial measures, but lower scores for most physical measures, with the lowest scores on the general health perceptions scale. In multivariable analyses, pulmonary exacerbations in the past 6 months were strongly associated with the physical (p = 0.001) and psychosocial (p = 0.0003) scores. The physical score fell, on average, 6 points per exacerbation and the psychosocial score fell 3 points. Lung function, nutrition, 6-min walk distance, age, gender, and insurance status were not significantly associated with HRQOL in this study population. Those who declined to participate had significantly lower FEV(1) percent predicted and nutritional indexes. Our findings may not be generalizable to the entire CF population. CONCLUSION: Recent pulmonary exacerbations have a profound negative impact on HRQOL that is not explained by differences in lung function, nutritional status, or demographic factors.