Najat Ziyadeh - Academia.edu (original) (raw)
Papers by Najat Ziyadeh
Thesis (M.A.)--Boston University, 2001. Includes bibliographical references (leaves 76-98).
Obesity (Silver Spring, Md.), 2016
To examine the relationship between gender expression (GE) and BMI in adolescence. Repeated measu... more To examine the relationship between gender expression (GE) and BMI in adolescence. Repeated measures of weight-related behaviors and BMI were collected from 1996 to 2011 via annual/biennial self-report surveys from youth aged 10 to 23 years (6,693 females, 2,978 males) in the longitudinal Growing Up Today Study. GE (very conforming [referent], mostly conforming, nonconforming) was assessed in 2010/11. Sex-stratified, multivariable linear models estimated GE group differences in BMI and the contribution of sexual orientation and weight-related exposures to group differences. Models for males included interaction terms for GE with age. In females, mostly conforming youth had 0.53 kg m(-2) and nonconforming had 1.23 kg m(-2) higher BMI; when adding adjustment for sexual orientation and weight-related exposures, GE group estimates were attenuated up to 8% and remained statistically significant. In males, mostly conforming youth had -0.67 kg m(-2) and nonconforming had -1.99 kg m(-2) low...
Background: Long-term consequences of stigma against sexual minorities for health-related quality... more Background: Long-term consequences of stigma against sexual minorities for health-related quality of life (HRQL) are unknown. Methods: We used data from 6,194 females and males in the Growing Up Today Study, a prospective cohort of U.S. youth, to examine predictors of sexual orientation disparities in HRQL. In 2013, participants (ages 18-31 years) reported sexual orientation (Completely Heterosexual [CH], Mostly Heterosexual [MH], Bisexual [B], and Lesbian/Gay [LG])). Unlike other studies, we used EQ-5D-5L, a preference-based measure recommended in cost-effectiveness analysis, to assess HRQL (range: 0 [death] to 1 [perfect health]). Participants previously reported past-year bullying victimization (range: 1 [never] to 5 [several times/week]) and self-perceived social standing (range: 1 [top] to 10 [bottom]) in adolescence. Longitudinal, multivariable linear regression models were used to assess the effect of bullying and social standing in adolescence on sexual orientation HRQL scor...
Background: Violating societal norms for masculine and feminine appearance and behavior puts one ... more Background: Violating societal norms for masculine and feminine appearance and behavior puts one at heightened risk of harassment and discrimination, but the impact of these adverse experiences on health-related quality of life (HRQL) is unknown. Purpose: To examine the relationship between gender expression and HRQL in a U.S. cohort. Methods: Using data from the Growing Up Today Study (n=4,769), a prospective cohort of young adults, we assessed socially assigned gender expression with a self-report measure on how others perceive one’s appearance and mannerisms, from very feminine to very masculine. A gender-specific continuous summary score was created (range: 1 [most conforming] to 7 [most nonconforming]). To assess HRQL, we used the EQ-5D, a population standardized instrument recommended in health economics (range: 0 [low] to 1 [high]). We used multivariable linear models, adjusted for age, race/ethnicity, and sexual orientation, to model the relationship between socially assigne...
International Journal of Eating Disorders
Preventing chronic disease, 2008
Early identification and treatment of disordered eating and weight control behaviors may prevent ... more Early identification and treatment of disordered eating and weight control behaviors may prevent progression and reduce the risk of chronic health consequences. The National Eating Disorders Screening Program coordinated the first-ever nationwide eating disorders screening initiative for high schools in the United States in 2000. Students completed a self-report screening questionnaire that included the Eating Attitudes Test (EAT-26) and items on vomiting or exercising to control weight, binge eating, and history of treatment for eating disorders. Multivariate regression analyses examined sex and racial/ethnic differences. Almost 15% of girls and 4% of boys scored at or above the threshold of 20 on the EAT-26, which indicated a possible eating disorder. Among girls, we observed few significant differences between ethnic groups in eating disorder symptoms, whereas among boys, more African American, American Indian, Asian/Pacific Islander, and Latino boys reported symptoms than did wh...
Pharmacoepidemiology and Drug Safety, 2008
The risk of coronary heart disease (CHD) in users of antidiabetic agents must be quantified to pe... more The risk of coronary heart disease (CHD) in users of antidiabetic agents must be quantified to permit reasoned therapeutic choices. To assess the risk of myocardial infarction (MI) and coronary revascularization (CR), in diabetic patients who began rosiglitazone, pioglitazone, metformin, or sulfonylureas. We conducted a retrospective cohort study of MI and CR in the PharMetrics database. We performed head-to-head comparisons using propensity-score-stratified Cox proportional hazards models, examining risks both on-treatment and during total follow-up before regimen switches. For the combined outcome (MI and CR), the crude rates per 1000 person years were 9 on monotherapy, 13 on dual therapy, and 21 on therapies combined with insulin. In the absence of insulin, regimens containing thiazolidinediones (TZDs) tended toward lower risk than comparable regimens containing sulfonylureas and higher risk than those containing metformin. The summary hazard ratio for rosiglitazone versus pioglitazone was 1.04 (95%CI: 0.94-1.14) for total follow-up and 1.05 (0.92-1.19) for on-treatment time. For MI, the hazard ratios were 1.07 (0.89-1.27) for total follow-up and 1.21 (0.95-1.54) for on-treatment time. The present data indicate that the risk of CHD in patients using TZDs appears to lie between the risks associated with sulfonylureas and metformin. Neither the risk of MI and CR together nor the risk of MI alone was significantly different between rosiglitazone and pioglitazone. A nonsignificant observed excess risk of 21% for MI during on-treatment time will require combination with the results of other studies to provide a reliable assessment.
Pharmacoepidemiology and Drug Safety, 2012
Purpose Studies of cancer based solely on health insurance claims data typically lack information... more Purpose Studies of cancer based solely on health insurance claims data typically lack information on cancer clinical characteristics that are strong predictors of treatment and prognosis. Our objective was to evaluate routinely collected cancer clinical data for adjustment of confounding using an example evaluation of mortality associated with aromatase inhibitors and tamoxifen. Methods This cohort study identified women with breast cancer from 2008 through 2010 using health insurance claims data linked to clinical information on stage at diagnosis, current clinical status, histology, and other clinical markers. Estimated mortality rates (MRs) and 95% confidence intervals (CI) were compared between users of aromatase inhibitors or tamoxifen, adjusted for claims-identified covariates and additionally for the clinical variables using propensity scores and proportional hazards regression models. Results The overall (n = 7974) estimated MR was 69/1000 person-years (95%CI = 62-76 person-years), 308/1000 person-years (95% CI = 273-345 person-years) for women with metastasis, and 12/1000 person-years (95%CI = 8-16 person-years) for women without active cancer. Propensity score matching of aromatase inhibitor users (n = 777) with tamoxifen users (n = 535) removed many, but not all, covariate imbalances. The hazard ratios (HRs) of all-cause mortality comparing users of aromatase inhibitors with tamoxifen users ranged from 1.0 to 1.6, with the HR most similar to previous clinical trials (0.87) coming from the claims-only analysis. Conclusions We were able to address potential unmeasured confounders by linking clinical information to the claims data; however, there was no apparent improvement in confounding control in the chosen example. Conditioning eligibility on the clinical data restricted the sample size substantially.
Medical Care, 2009
Rapid safety assessment of novel vaccines, especially those targeted against pandemic influenza, ... more Rapid safety assessment of novel vaccines, especially those targeted against pandemic influenza, is a public health priority. Assess the feasibility of using healthcare claims data to rapidly detect influenza vaccine adverse events using sequential analytic methods. Retrospective pilot study simulating prospective surveillance using 6 cumulative monthly administrative claims data extracts. The first included encounters occurring in October; each subsequent extract included an additional month of encounters. Ten adverse events were evaluated, comparing postvaccination rates during the 2006-2007 influenza season to those expected based on rates observed in the prior season. Members of a large, multistate health insurer who had a claim for influenza vaccination during the 2005-2006 or 2006-2007 influenza seasons. The completeness of monthly claims extracts. Most vaccinations and outcomes were identified early in the 2006-2007 season; about 50% of vaccinations and short latency events were identified in the second monthly data extract, which would typically become available by mid-December, and 80% of vaccinations and events were identified in the third extract. With respect to overall claims lag, approximately 90% of vaccinations and events were identified within 1 to 2 months after vaccination, regardless of vaccination month. This study suggests that administrative claims data might contribute to same season influenza vaccine safety surveillance in large, defined populations, especially during a threat of pandemic influenza. Based on our previous work, we believe this method could be applied to multiple health plans' data to monitor a large portion of the US population.
Journal of the American Academy of Child & Adolescent Psychiatry, 2004
To examine sexual orientation group differences in eating disorder symptoms in adolescent girls a... more To examine sexual orientation group differences in eating disorder symptoms in adolescent girls and boys. Cross-sectional associations were examined using multivariate regression techniques using data gathered in 1999 from 10,583 adolescents in the Growing Up Today Study, a cohort of children of women participating in the Nurses' Health Study II. Ninety-two percent of the cohort described themselves as heterosexual, 5% as mostly heterosexual, 1% as lesbian/gay/bisexual, and 2% as unsure. Both mostly heterosexual girls and boys had greater concerns with weight and appearance and were less happy with their bodies compared with same-gender heterosexuals (all p < .05). Compared with heterosexual girls, the mostly heterosexual girls were more likely to vomit/use laxatives to control weight (odds ratio 1.7; 95% confidence interval = 1.2-2.6) and to binge eat (odds ratio 2.3; 95% confidence interval = 1.4-3.8) in the past year. Compared with heterosexual boys, gay/bisexual boys were more concerned with trying to look like men in the media (p < .05) and more likely to binge (odds ratio 15.2; 95% confidence interval = 3.3-69). Compared with heterosexual girls, lesbian/bisexual girls were happier with their bodies (p < .05) and less concerned with trying to look like women in the media (p < .05). Mostly heterosexual girls and boys are a newly identified group at increased risk of eating disorder symptoms. Gay/bisexual boys were also at increased risk.
Journal of School Health, 2011
Early identification can greatly impact the trajectory of eating disorders, and school-based scre... more Early identification can greatly impact the trajectory of eating disorders, and school-based screening is 1 avenue for identifying those at risk. To be feasible in a school setting, a screening program must use a brief, valid screening tool. The aim of this study was to assess how well brief attitudinal and behavioral survey items identify adolescents at risk in a large sample of high school students from across the United States. Data were drawn from the National Eating Disorder Screening Program, the first-ever national eating disorders screening initiative for US high schools. A 2-stage, clustered sampling method was used to randomly select a subset of student screening forms (n = 5740), which included the Eating Attitudes Test (EAT-26), behavioral questions assessing the frequency of vomiting and binge eating in the past 3 months, and an attitudinal item that assessed preoccupation with thinness. Nearly 12% of females and 3% of males reported vomiting to control their weight and 17% of females and 10% of males reported binge eating 1 or more times per month. Approximately 24% of females and 8% of males report being preoccupied with being thinner. We found that the attitudinal measure yielded high sensitivity and specificity. Combined screening measures that used both the attitudinal and behavioral items yielded slightly higher sensitivity values than those found with the attitudinal measure alone. High school administrators should include items that assess both preoccupation with thinness as well as behavioral items that deal with eating disorders on student health surveys.
Journal of Clinical Psychopharmacology, 2012
Pharmacovigilance studies of spontaneous adverse event report databases are used to raise hypothe... more Pharmacovigilance studies of spontaneous adverse event report databases are used to raise hypotheses about potential safety events. Such studies have found a disproportionately higher number of pituitary tumor reports for risperidone. Because there is a high prevalence of clinically "silent" pituitary adenomas, any increased workup in risperidone users, for example, secondary to hyperprolactinemia, might account for the increased reports. We undertook a detailed study of medical record-confirmed newly diagnosed pituitary tumors with mass effect in patients prescribed antipsychotics to evaluate the effect of risperidone. We conducted retrospective studies in 2 large administrative health care databases with access to medical records. Patients were classified into risperidone or other atypical antipsychotic exposure groups. Records with administrative codes indicative of possible cases in the follow-up period were reviewed to confirm the diagnosis of new pituitary tumor and presence of mass effects. The hazard ratio of confirmed pituitary tumors with mass effect was 1.0 (95% confidence interval, 0.5-1.9). Whereas the precision of the hazard ratio was limited by low event rates, despite examination of 409,823 patients' records, ancillary analyses supported the interpretation of no elevated risk. Evidence was found for detection bias that may explain previous pharmacovigilance findings. There was no evidence of increased risk of pituitary tumor with mass effect with risperidone in either cohort or case-control analyses. We cannot rule out a small risk (<2-fold), or a risk that may develop with additional years of exposure or follow-up, or a risk of microadenomas or prolactinomas.
Journal of Adolescent Health, 2008
Purpose-Using data from an eating disorders screening initiative conducted in high schools across... more Purpose-Using data from an eating disorders screening initiative conducted in high schools across the United States, we examined the relationship between vomiting frequency and irregular menses in a nonclinical sample of adolescent females.
Journal of Adolescent Health, 2007
Journal of Adolescent Health, 2003
Purpose: Adolescent obesity represents one of the most critical emerging public health problems n... more Purpose: Adolescent obesity represents one of the most critical emerging public health problems nationally. Large ethnic and socioeconomic disparities in overweight have been documented. Studies with adults suggest that lesbian and bisexual women are at increased risk of overweight, but no research has examined whether these disparities affect adolescents. The aim of this analysis was to examine the relationship between overweight and sexual orientation in a nationwide cohort of adolescents. Methods: The Growing Up Today Study (GUTS) is a longitudinal cohort study of 16,862 U.S. adolescent girls and boys. The study was begun in 1996, and surveys are mailed annually to participants and include questions on demographics, height, weight, maturational stage, and multiple health behaviors in the past year. In 1999, an item on sexual orientation was added to the questionnaire. Multivariate regression analyses using 1999 data were conducted to examine cross-sectional associations between sexual orientation and body mass index (BMI; kg/m 2 ) and overweight (Ն85th percentile for age and sex) among 10,136 subjects, ages 12 to 17 years. Heterosexuals served as the reference group. Results: The mean age was 14.4 (Ϯ1.6 years), and 96% of the cohort was of white ethnicity. 91% (5,475) of girls and 94% (3,821) of boys described themselves as heterosexual, 6% (369) of girls and 3% (142) of boys as mostly heterosexual, 1% (62 girls, 41 boys) as gay/bisexual, and 2% (143 girls, 83 boys) as unsure. Mean BMI (kg/m 2 ) was 21.5 among girls and 21.7 among boys; 16% of girls and 23% of boys were overweight. Compared to heterosexuals, gay/bisexuals and mostly heterosexuals were older, more advanced in maturational stage, and, among girls, more likely to have reached menarche; these covariates were positively associated with BMI and so were included in multivariate models as potential confounders. Notable differences in mean BMI were observed across orientation groups in both females (heterosexual:
Journal of Adolescent Health, 2002
Epidemiology, 2004
Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are rare disorders characterize... more Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are rare disorders characterized by platelet aggregation, microthrombi, and resulting tissue damage. We studied the incidence and possible risk factors for these diseases in 3 large populations in the United States, United Kingdom, and Canada. Data were derived from a large health insurer in the United States, general practices in the United Kingdom, and the Province of Saskatchewan. We identified potential cases of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome in computerized data and verified them by medical record review. We estimated incidence rates for thrombotic thrombocytopenia purpura and hemolytic uremic syndrome together and separately, and we conducted a case-control study to evaluate potential risk factors. The age-sex standardized incidence of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome was higher than previously reported (6.5, 2.2, and 3.2 per million per year in the United States, United Kingdom, and Saskatchewan, respectively), but there was no secular trend. The incidence of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome was higher in women than men. Most cases of hemolytic uremic syndrome occurred before 20 years of age. We confirmed several known risk factors for thrombotic thrombocytopenia purpura and hemolytic uremic syndrome (cancer, bone marrow transplantation, pregnancy). The incidence of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome is higher than previously reported but does not appear to be rising. Apparent international differences in incidence could be the result of imprecision in identifying thrombotic thrombocytopenia purpura and hemolytic uremic syndrome in large research databases.
Drug Safety, 2007
Data on the incidence of serious allergic reactions to fluoroquinolone antibacterials are mainly ... more Data on the incidence of serious allergic reactions to fluoroquinolone antibacterials are mainly derived from spontaneous reports that cannot be used to accurately estimate incidence. This study estimated the drug-specific incidence of serious allergic reactions after fluoroquinolone, cephalosporin and phenoxymethylpenicillin potassium exposure, using claims for healthcare services with confirmation through medical record abstraction within a large health insurer database. Cohorts exposed to each antibacterial of interest (moxifloxacin, levofloxacin, ciprofloxacin, gatifloxacin, cephalosporins and penicillin) were identified, and followed for 14 days for anaphylaxis (9th revision of the International Classification of Diseases [ICD-9] code 995.0), other allergic drug reactions (ICD-9 995.2, 995.3) or cardiopulmonary resuscitation. The incidence per 10,000 first dispensings of any allergic diagnosis made in the hospital or emergency department was similar for moxifloxacin (4.3; 95% CI 3.5, 5.3), penicillin (4.7; 95% CI 3.8, 5.7) and ciprofloxacin (5.4; 95% CI 4.4, 6.5). The incidence for moxifloxacin was lower than that for levofloxacin (8.7; 95% CI 7.4, 10.0), gatifloxacin (6.7; 95% CI 5.6, 7.9) and the cephalosporins (7.5; 95% CI 6.3, 8.8). The incidence of anaphylaxis/anaphylactoid reactions after first dispensings was similar for the fluoroquinolones: 0.1 (95% CI 0.0, 0.3) for ciprofloxacin, 0.3 (95% CI 0.1, 0.5) for moxifloxacin, 0.3 (95% CI 0.1, 0.6) for gatifloxacin and 0.5 (95% CI 0.3, 0.9) for levofloxacin; and comparable with that of the cephalosporins (0.2; 95% CI 0.0, 0.4) and penicillin (0.1; 95% CI 0.0, 0.3). Anaphylactic reactions were rare and their incidence did not differ substantially among the drug groups studied. By determining the occurrence of reactions following defined exposures, these results provide a context for the interpretation of spontaneous reports of allergic reactions.
Thesis (M.A.)--Boston University, 2001. Includes bibliographical references (leaves 76-98).
Obesity (Silver Spring, Md.), 2016
To examine the relationship between gender expression (GE) and BMI in adolescence. Repeated measu... more To examine the relationship between gender expression (GE) and BMI in adolescence. Repeated measures of weight-related behaviors and BMI were collected from 1996 to 2011 via annual/biennial self-report surveys from youth aged 10 to 23 years (6,693 females, 2,978 males) in the longitudinal Growing Up Today Study. GE (very conforming [referent], mostly conforming, nonconforming) was assessed in 2010/11. Sex-stratified, multivariable linear models estimated GE group differences in BMI and the contribution of sexual orientation and weight-related exposures to group differences. Models for males included interaction terms for GE with age. In females, mostly conforming youth had 0.53 kg m(-2) and nonconforming had 1.23 kg m(-2) higher BMI; when adding adjustment for sexual orientation and weight-related exposures, GE group estimates were attenuated up to 8% and remained statistically significant. In males, mostly conforming youth had -0.67 kg m(-2) and nonconforming had -1.99 kg m(-2) low...
Background: Long-term consequences of stigma against sexual minorities for health-related quality... more Background: Long-term consequences of stigma against sexual minorities for health-related quality of life (HRQL) are unknown. Methods: We used data from 6,194 females and males in the Growing Up Today Study, a prospective cohort of U.S. youth, to examine predictors of sexual orientation disparities in HRQL. In 2013, participants (ages 18-31 years) reported sexual orientation (Completely Heterosexual [CH], Mostly Heterosexual [MH], Bisexual [B], and Lesbian/Gay [LG])). Unlike other studies, we used EQ-5D-5L, a preference-based measure recommended in cost-effectiveness analysis, to assess HRQL (range: 0 [death] to 1 [perfect health]). Participants previously reported past-year bullying victimization (range: 1 [never] to 5 [several times/week]) and self-perceived social standing (range: 1 [top] to 10 [bottom]) in adolescence. Longitudinal, multivariable linear regression models were used to assess the effect of bullying and social standing in adolescence on sexual orientation HRQL scor...
Background: Violating societal norms for masculine and feminine appearance and behavior puts one ... more Background: Violating societal norms for masculine and feminine appearance and behavior puts one at heightened risk of harassment and discrimination, but the impact of these adverse experiences on health-related quality of life (HRQL) is unknown. Purpose: To examine the relationship between gender expression and HRQL in a U.S. cohort. Methods: Using data from the Growing Up Today Study (n=4,769), a prospective cohort of young adults, we assessed socially assigned gender expression with a self-report measure on how others perceive one’s appearance and mannerisms, from very feminine to very masculine. A gender-specific continuous summary score was created (range: 1 [most conforming] to 7 [most nonconforming]). To assess HRQL, we used the EQ-5D, a population standardized instrument recommended in health economics (range: 0 [low] to 1 [high]). We used multivariable linear models, adjusted for age, race/ethnicity, and sexual orientation, to model the relationship between socially assigne...
International Journal of Eating Disorders
Preventing chronic disease, 2008
Early identification and treatment of disordered eating and weight control behaviors may prevent ... more Early identification and treatment of disordered eating and weight control behaviors may prevent progression and reduce the risk of chronic health consequences. The National Eating Disorders Screening Program coordinated the first-ever nationwide eating disorders screening initiative for high schools in the United States in 2000. Students completed a self-report screening questionnaire that included the Eating Attitudes Test (EAT-26) and items on vomiting or exercising to control weight, binge eating, and history of treatment for eating disorders. Multivariate regression analyses examined sex and racial/ethnic differences. Almost 15% of girls and 4% of boys scored at or above the threshold of 20 on the EAT-26, which indicated a possible eating disorder. Among girls, we observed few significant differences between ethnic groups in eating disorder symptoms, whereas among boys, more African American, American Indian, Asian/Pacific Islander, and Latino boys reported symptoms than did wh...
Pharmacoepidemiology and Drug Safety, 2008
The risk of coronary heart disease (CHD) in users of antidiabetic agents must be quantified to pe... more The risk of coronary heart disease (CHD) in users of antidiabetic agents must be quantified to permit reasoned therapeutic choices. To assess the risk of myocardial infarction (MI) and coronary revascularization (CR), in diabetic patients who began rosiglitazone, pioglitazone, metformin, or sulfonylureas. We conducted a retrospective cohort study of MI and CR in the PharMetrics database. We performed head-to-head comparisons using propensity-score-stratified Cox proportional hazards models, examining risks both on-treatment and during total follow-up before regimen switches. For the combined outcome (MI and CR), the crude rates per 1000 person years were 9 on monotherapy, 13 on dual therapy, and 21 on therapies combined with insulin. In the absence of insulin, regimens containing thiazolidinediones (TZDs) tended toward lower risk than comparable regimens containing sulfonylureas and higher risk than those containing metformin. The summary hazard ratio for rosiglitazone versus pioglitazone was 1.04 (95%CI: 0.94-1.14) for total follow-up and 1.05 (0.92-1.19) for on-treatment time. For MI, the hazard ratios were 1.07 (0.89-1.27) for total follow-up and 1.21 (0.95-1.54) for on-treatment time. The present data indicate that the risk of CHD in patients using TZDs appears to lie between the risks associated with sulfonylureas and metformin. Neither the risk of MI and CR together nor the risk of MI alone was significantly different between rosiglitazone and pioglitazone. A nonsignificant observed excess risk of 21% for MI during on-treatment time will require combination with the results of other studies to provide a reliable assessment.
Pharmacoepidemiology and Drug Safety, 2012
Purpose Studies of cancer based solely on health insurance claims data typically lack information... more Purpose Studies of cancer based solely on health insurance claims data typically lack information on cancer clinical characteristics that are strong predictors of treatment and prognosis. Our objective was to evaluate routinely collected cancer clinical data for adjustment of confounding using an example evaluation of mortality associated with aromatase inhibitors and tamoxifen. Methods This cohort study identified women with breast cancer from 2008 through 2010 using health insurance claims data linked to clinical information on stage at diagnosis, current clinical status, histology, and other clinical markers. Estimated mortality rates (MRs) and 95% confidence intervals (CI) were compared between users of aromatase inhibitors or tamoxifen, adjusted for claims-identified covariates and additionally for the clinical variables using propensity scores and proportional hazards regression models. Results The overall (n = 7974) estimated MR was 69/1000 person-years (95%CI = 62-76 person-years), 308/1000 person-years (95% CI = 273-345 person-years) for women with metastasis, and 12/1000 person-years (95%CI = 8-16 person-years) for women without active cancer. Propensity score matching of aromatase inhibitor users (n = 777) with tamoxifen users (n = 535) removed many, but not all, covariate imbalances. The hazard ratios (HRs) of all-cause mortality comparing users of aromatase inhibitors with tamoxifen users ranged from 1.0 to 1.6, with the HR most similar to previous clinical trials (0.87) coming from the claims-only analysis. Conclusions We were able to address potential unmeasured confounders by linking clinical information to the claims data; however, there was no apparent improvement in confounding control in the chosen example. Conditioning eligibility on the clinical data restricted the sample size substantially.
Medical Care, 2009
Rapid safety assessment of novel vaccines, especially those targeted against pandemic influenza, ... more Rapid safety assessment of novel vaccines, especially those targeted against pandemic influenza, is a public health priority. Assess the feasibility of using healthcare claims data to rapidly detect influenza vaccine adverse events using sequential analytic methods. Retrospective pilot study simulating prospective surveillance using 6 cumulative monthly administrative claims data extracts. The first included encounters occurring in October; each subsequent extract included an additional month of encounters. Ten adverse events were evaluated, comparing postvaccination rates during the 2006-2007 influenza season to those expected based on rates observed in the prior season. Members of a large, multistate health insurer who had a claim for influenza vaccination during the 2005-2006 or 2006-2007 influenza seasons. The completeness of monthly claims extracts. Most vaccinations and outcomes were identified early in the 2006-2007 season; about 50% of vaccinations and short latency events were identified in the second monthly data extract, which would typically become available by mid-December, and 80% of vaccinations and events were identified in the third extract. With respect to overall claims lag, approximately 90% of vaccinations and events were identified within 1 to 2 months after vaccination, regardless of vaccination month. This study suggests that administrative claims data might contribute to same season influenza vaccine safety surveillance in large, defined populations, especially during a threat of pandemic influenza. Based on our previous work, we believe this method could be applied to multiple health plans' data to monitor a large portion of the US population.
Journal of the American Academy of Child & Adolescent Psychiatry, 2004
To examine sexual orientation group differences in eating disorder symptoms in adolescent girls a... more To examine sexual orientation group differences in eating disorder symptoms in adolescent girls and boys. Cross-sectional associations were examined using multivariate regression techniques using data gathered in 1999 from 10,583 adolescents in the Growing Up Today Study, a cohort of children of women participating in the Nurses' Health Study II. Ninety-two percent of the cohort described themselves as heterosexual, 5% as mostly heterosexual, 1% as lesbian/gay/bisexual, and 2% as unsure. Both mostly heterosexual girls and boys had greater concerns with weight and appearance and were less happy with their bodies compared with same-gender heterosexuals (all p < .05). Compared with heterosexual girls, the mostly heterosexual girls were more likely to vomit/use laxatives to control weight (odds ratio 1.7; 95% confidence interval = 1.2-2.6) and to binge eat (odds ratio 2.3; 95% confidence interval = 1.4-3.8) in the past year. Compared with heterosexual boys, gay/bisexual boys were more concerned with trying to look like men in the media (p < .05) and more likely to binge (odds ratio 15.2; 95% confidence interval = 3.3-69). Compared with heterosexual girls, lesbian/bisexual girls were happier with their bodies (p < .05) and less concerned with trying to look like women in the media (p < .05). Mostly heterosexual girls and boys are a newly identified group at increased risk of eating disorder symptoms. Gay/bisexual boys were also at increased risk.
Journal of School Health, 2011
Early identification can greatly impact the trajectory of eating disorders, and school-based scre... more Early identification can greatly impact the trajectory of eating disorders, and school-based screening is 1 avenue for identifying those at risk. To be feasible in a school setting, a screening program must use a brief, valid screening tool. The aim of this study was to assess how well brief attitudinal and behavioral survey items identify adolescents at risk in a large sample of high school students from across the United States. Data were drawn from the National Eating Disorder Screening Program, the first-ever national eating disorders screening initiative for US high schools. A 2-stage, clustered sampling method was used to randomly select a subset of student screening forms (n = 5740), which included the Eating Attitudes Test (EAT-26), behavioral questions assessing the frequency of vomiting and binge eating in the past 3 months, and an attitudinal item that assessed preoccupation with thinness. Nearly 12% of females and 3% of males reported vomiting to control their weight and 17% of females and 10% of males reported binge eating 1 or more times per month. Approximately 24% of females and 8% of males report being preoccupied with being thinner. We found that the attitudinal measure yielded high sensitivity and specificity. Combined screening measures that used both the attitudinal and behavioral items yielded slightly higher sensitivity values than those found with the attitudinal measure alone. High school administrators should include items that assess both preoccupation with thinness as well as behavioral items that deal with eating disorders on student health surveys.
Journal of Clinical Psychopharmacology, 2012
Pharmacovigilance studies of spontaneous adverse event report databases are used to raise hypothe... more Pharmacovigilance studies of spontaneous adverse event report databases are used to raise hypotheses about potential safety events. Such studies have found a disproportionately higher number of pituitary tumor reports for risperidone. Because there is a high prevalence of clinically "silent" pituitary adenomas, any increased workup in risperidone users, for example, secondary to hyperprolactinemia, might account for the increased reports. We undertook a detailed study of medical record-confirmed newly diagnosed pituitary tumors with mass effect in patients prescribed antipsychotics to evaluate the effect of risperidone. We conducted retrospective studies in 2 large administrative health care databases with access to medical records. Patients were classified into risperidone or other atypical antipsychotic exposure groups. Records with administrative codes indicative of possible cases in the follow-up period were reviewed to confirm the diagnosis of new pituitary tumor and presence of mass effects. The hazard ratio of confirmed pituitary tumors with mass effect was 1.0 (95% confidence interval, 0.5-1.9). Whereas the precision of the hazard ratio was limited by low event rates, despite examination of 409,823 patients' records, ancillary analyses supported the interpretation of no elevated risk. Evidence was found for detection bias that may explain previous pharmacovigilance findings. There was no evidence of increased risk of pituitary tumor with mass effect with risperidone in either cohort or case-control analyses. We cannot rule out a small risk (<2-fold), or a risk that may develop with additional years of exposure or follow-up, or a risk of microadenomas or prolactinomas.
Journal of Adolescent Health, 2008
Purpose-Using data from an eating disorders screening initiative conducted in high schools across... more Purpose-Using data from an eating disorders screening initiative conducted in high schools across the United States, we examined the relationship between vomiting frequency and irregular menses in a nonclinical sample of adolescent females.
Journal of Adolescent Health, 2007
Journal of Adolescent Health, 2003
Purpose: Adolescent obesity represents one of the most critical emerging public health problems n... more Purpose: Adolescent obesity represents one of the most critical emerging public health problems nationally. Large ethnic and socioeconomic disparities in overweight have been documented. Studies with adults suggest that lesbian and bisexual women are at increased risk of overweight, but no research has examined whether these disparities affect adolescents. The aim of this analysis was to examine the relationship between overweight and sexual orientation in a nationwide cohort of adolescents. Methods: The Growing Up Today Study (GUTS) is a longitudinal cohort study of 16,862 U.S. adolescent girls and boys. The study was begun in 1996, and surveys are mailed annually to participants and include questions on demographics, height, weight, maturational stage, and multiple health behaviors in the past year. In 1999, an item on sexual orientation was added to the questionnaire. Multivariate regression analyses using 1999 data were conducted to examine cross-sectional associations between sexual orientation and body mass index (BMI; kg/m 2 ) and overweight (Ն85th percentile for age and sex) among 10,136 subjects, ages 12 to 17 years. Heterosexuals served as the reference group. Results: The mean age was 14.4 (Ϯ1.6 years), and 96% of the cohort was of white ethnicity. 91% (5,475) of girls and 94% (3,821) of boys described themselves as heterosexual, 6% (369) of girls and 3% (142) of boys as mostly heterosexual, 1% (62 girls, 41 boys) as gay/bisexual, and 2% (143 girls, 83 boys) as unsure. Mean BMI (kg/m 2 ) was 21.5 among girls and 21.7 among boys; 16% of girls and 23% of boys were overweight. Compared to heterosexuals, gay/bisexuals and mostly heterosexuals were older, more advanced in maturational stage, and, among girls, more likely to have reached menarche; these covariates were positively associated with BMI and so were included in multivariate models as potential confounders. Notable differences in mean BMI were observed across orientation groups in both females (heterosexual:
Journal of Adolescent Health, 2002
Epidemiology, 2004
Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are rare disorders characterize... more Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are rare disorders characterized by platelet aggregation, microthrombi, and resulting tissue damage. We studied the incidence and possible risk factors for these diseases in 3 large populations in the United States, United Kingdom, and Canada. Data were derived from a large health insurer in the United States, general practices in the United Kingdom, and the Province of Saskatchewan. We identified potential cases of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome in computerized data and verified them by medical record review. We estimated incidence rates for thrombotic thrombocytopenia purpura and hemolytic uremic syndrome together and separately, and we conducted a case-control study to evaluate potential risk factors. The age-sex standardized incidence of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome was higher than previously reported (6.5, 2.2, and 3.2 per million per year in the United States, United Kingdom, and Saskatchewan, respectively), but there was no secular trend. The incidence of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome was higher in women than men. Most cases of hemolytic uremic syndrome occurred before 20 years of age. We confirmed several known risk factors for thrombotic thrombocytopenia purpura and hemolytic uremic syndrome (cancer, bone marrow transplantation, pregnancy). The incidence of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome is higher than previously reported but does not appear to be rising. Apparent international differences in incidence could be the result of imprecision in identifying thrombotic thrombocytopenia purpura and hemolytic uremic syndrome in large research databases.
Drug Safety, 2007
Data on the incidence of serious allergic reactions to fluoroquinolone antibacterials are mainly ... more Data on the incidence of serious allergic reactions to fluoroquinolone antibacterials are mainly derived from spontaneous reports that cannot be used to accurately estimate incidence. This study estimated the drug-specific incidence of serious allergic reactions after fluoroquinolone, cephalosporin and phenoxymethylpenicillin potassium exposure, using claims for healthcare services with confirmation through medical record abstraction within a large health insurer database. Cohorts exposed to each antibacterial of interest (moxifloxacin, levofloxacin, ciprofloxacin, gatifloxacin, cephalosporins and penicillin) were identified, and followed for 14 days for anaphylaxis (9th revision of the International Classification of Diseases [ICD-9] code 995.0), other allergic drug reactions (ICD-9 995.2, 995.3) or cardiopulmonary resuscitation. The incidence per 10,000 first dispensings of any allergic diagnosis made in the hospital or emergency department was similar for moxifloxacin (4.3; 95% CI 3.5, 5.3), penicillin (4.7; 95% CI 3.8, 5.7) and ciprofloxacin (5.4; 95% CI 4.4, 6.5). The incidence for moxifloxacin was lower than that for levofloxacin (8.7; 95% CI 7.4, 10.0), gatifloxacin (6.7; 95% CI 5.6, 7.9) and the cephalosporins (7.5; 95% CI 6.3, 8.8). The incidence of anaphylaxis/anaphylactoid reactions after first dispensings was similar for the fluoroquinolones: 0.1 (95% CI 0.0, 0.3) for ciprofloxacin, 0.3 (95% CI 0.1, 0.5) for moxifloxacin, 0.3 (95% CI 0.1, 0.6) for gatifloxacin and 0.5 (95% CI 0.3, 0.9) for levofloxacin; and comparable with that of the cephalosporins (0.2; 95% CI 0.0, 0.4) and penicillin (0.1; 95% CI 0.0, 0.3). Anaphylactic reactions were rare and their incidence did not differ substantially among the drug groups studied. By determining the occurrence of reactions following defined exposures, these results provide a context for the interpretation of spontaneous reports of allergic reactions.