Validation of claims-based algorithms to identify non-live birth outcomes.

PURPOSE: Perinatal epidemiology studies using healthcare utilization databases are often restricted to live births, largely due to the lack of established algorithms to identify non-live births. The study objective was to develop and validate claims-based algorithms for the ascertainment of non-live births. METHODS: Using the Mass General Brigham Research Patient Data Registry 2000-2014, we assembled a cohort of women enrolled in Medicaid with a non-live birth. Based on ≥1 inpatient or ≥2 outpatient diagnosis/procedure codes, we identified and randomly sampled 100 potential stillbirth, spontaneous abortion, and termination cases each. For the secondary definitions, we excluded cases with codes for other pregnancy outcomes within ±5 days of the outcome of interest and relaxed the definitions for spontaneous abortion and termination by allowing cases with one outpatient diagnosis only. Cases were adjudicated based on medical chart review. We estimated the positive predictive value (PPV) for each outcome. RESULTS: The PPV was 71.0% (95% CI, 61.1-79.6) for stillbirth; 79.0% (69.7-86.5) for spontaneous abortion, and 93.0% (86.1-97.1) for termination. When excluding cases with adjacent codes for other pregnancy outcomes and further relaxing the definition, the PPV increased to 80.6% (69.5-88.9) for stillbirth, 86.6% (80.5-91.3) for spontaneous abortion and 94.9% (91.1-97.4) for termination. The PPV for the composite outcome using the relaxed definition was 94.4% (92.3-96.1). CONCLUSIONS: Our findings suggest non-live birth outcomes can be identified in a valid manner in epidemiological studies based on healthcare utilization databases.

Development and Validation of Algorithms to Estimate Live Birth Gestational Age in Medicaid Analytic eXtract Data.

BACKGROUND: While healthcare utilization data are useful for postmarketing surveillance of drug safety in pregnancy, the start of pregnancy and gestational age at birth are often incompletely recorded or missing. Our objective was to develop and validate a claims-based live birth gestational age algorithm. METHODS: Using the Medicaid Analytic eXtract (MAX) linked to birth certificates in three states, we developed four candidate algorithms based on: preterm codes; preterm or postterm codes; timing of prenatal care; and prediction models - using conventional regression and machine-learning approaches with a broad range of prespecified and empirically selected predictors. We assessed algorithm performance based on mean squared error (MSE) and proportion of pregnancies with estimated gestational age within 1 and 2 weeks of the gold standard, defined as the clinical or obstetric estimate of gestation on the birth certificate. We validated the best-performing algorithms against medical records in a nationwide sample. We quantified misclassification of select drug exposure scenarios due to estimated gestational age as positive predictive value (PPV), sensitivity, and specificity. RESULTS: Among 114,117 eligible pregnancies, the random forest model with all predictors emerged as the best performing algorithm: MSE 1.5; 84.8% within 1 week and 96.3% within 2 weeks, with similar performance in the nationwide validation cohort. For all exposure scenarios, PPVs were >93.8%, sensitivities >94.3%, and specificities >99.4%. CONCLUSIONS: We developed a highly accurate algorithm for estimating gestational age among live births in the nationwide MAX data, further supporting the value of these data for drug safety surveillance in pregnancy. See video abstract at, http://links.lww.com/EDE/B989 .

Rates of, and factors associated with, switching among generic levothyroxine preparations in commercially insured American adults.

IMPORTANCE: Some practice guidelines warn against generic L-thyroxine preparation switching. OBJECTIVE: To examine the rates of generic L-thyroxine preparation switching within one year of initiating L-thyroxine, and to examine factors associated with switching. DESIGN AND SETTING: Retrospective study using national data from a large administrative claims database from January 2008 through November 2018. PATIENTS: Medicare or commercially insured adults (≥18 years) who filled a generic L-thyroxine preparation. MAIN OUTCOME MEASURES: At least one switch from one generic L-thyroxine preparation to another within 1 year of L-thyroxine initiation defined by prescription fills. RESULTS: From January 2008 to November 2018, we included 483,390 patients who initiated generic L-thyroxine: mean (SD) age was 61.4 years (15.2), 75.2% were female, 72.6% were white. Within 1 year of initiating therapy, 98,013 (20%) switched to another L-thyroxine generic preparation at least once. In a multivariate logistic regression analysis, factors associated with switching included the number of pharmacies visited to fill L-thyroxine (>2 vs 1 adjusted OR [aOR] 7.15, 95% confidence interval [CI] 6.97-7.34), age ≥75 vs. <45 years (aOR 1.29, 95% CI 1.26-1.33), history of thyroid surgery (aOR 1.22, 95% CI 1.13-1.31), and first L-thyroxine fill date in 2018 vs. 2008 (aOR 3.32, 95% CI 3.14-3.51). CONCLUSIONS AND RELEVANCE: One in five patients switched among generic L-thyroxine manufacturers within one year of treatment initiation. Generic L-thyroxine switching occurred more often when more pharmacies were used to fill L-thyroxine. Given existing guideline recommendations, additional studies should clarify the impact of generic L-thyroxine switching on thyroid hormone values.

Association Between Generic-to-Generic Levothyroxine Switching and Thyrotropin Levels Among US Adults.

IMPORTANCE: Switching among generic levothyroxine sodium products made by different manufacturers typically occurs at the pharmacy and may affect serum thyrotropin (TSH) levels. OBJECTIVE: To compare TSH levels between patients who continued taking the same sourced generic levothyroxine product and those who switched. DESIGN, SETTING, AND PARTICIPANTS: This comparative effectiveness research study with 1:1 propensity matching used data from OptumLabs Data Warehouse, a national administrative claims database linked to laboratory test results. Adults aged 18 years or older were included if they filled a generic levothyroxine prescription between January 1, 2008, and June 30, 2019, and had a stable drug dose, the same drug manufacturer, and a normal TSH level (0.3-4.4 mIU/L) for at least 3 months before either continuing to take the same product or switching among generic levothyroxine products (index date). Patients were excluded if they were pregnant, had diagnosed hypopituitarism or hyperthyroidism, or had a medical condition or used medications that could affect thyrotropin levels. They were also excluded if they filled a prescription for other forms of thyroid replacement therapy between 6 months before the index date and when the first TSH level was obtained 6 weeks to 12 months after the index date. Data were analyzed from December 1, 2019, to November 24, 2021. MAIN OUTCOMES AND MEASURES: Proportion of individuals with a normal (0.3-4.4 mIU/L) or markedly abnormal (<0.1 or >10.0 mIU/L) TSH level using the first available laboratory result 6 weeks to 12 months after the index date. A propensity score model was developed to minimize confounding using logistic regression with the binary outcome of continuing the same sourced levothyroxine product vs switching generic levothyroxine. Covariates were demographics, comorbidities, and baseline TSH level. The balance among the treatment groups was evaluated by comparing standardized mean differences of baseline covariates between the groups. RESULTS: A total of 15 829 patients filled generic levothyroxine (mean [SD] age, 58.9 [14.6] years; 73.4% [11 624] were women; 4.5% [705] were Asian, 10.2% [1617] were Black, 11.4% [1801] were Hispanic, and 71.4% [11 295] were White individuals); of these patients, 56.3% [8905] received a daily levothyroxine dose of 50 µg or less. A total of 13 049 patients (82.4%) continued taking the same sourced preparation, and 2780 (17.6%) switched among generic levothyroxine preparations. Among 2780 propensity-matched patient pairs, the proportion of patients with a normal TSH level after the index date was 82.7% (2298) among nonswitchers and 84.5% (2348) among switchers (risk difference, -0.018; 95% CI, -0.038 to 0.002; P = .07). The proportion of patients with a markedly abnormal TSH level after the index date was 3.1% (87) among nonswitchers and 2.5% (69) among switchers (risk difference, 0.007; 95% CI, -0.002 to 0.015; P = .14). The mean (SD) TSH levels after the index date were 2.7 (2.3) mIU/L among nonswitchers and 2.7 (3.3) mIU/L among switchers (P = .94). CONCLUSIONS AND RELEVANCE: Results of this comparative effectiveness research study suggest that switching among different generic levothyroxine products was not associated with clinically significant changes in TSH level. These findings conflict with the current guideline recommendation that warns clinicians about potential changes in TSH level associated with switching among levothyroxine products sourced from different manufacturers.

Cardiovascular outcomes and rates of fractures and falls among patients with brand-name versus generic L-thyroxine use.

PURPOSE: To compare cardiovascular outcomes and rates of fractures and falls among patients with persistent brand-name versus generic L-thyroxine use. METHODS: Retrospective, 1:1 propensity-matched longitudinal study using a national administrative claims database to examine adults (≥18 years) who initiated either brand or generic L-thyroxine between 2008 and 2018, censored at switch or discontinuation of L-thyroxine formulation or disenrollment from the health plan. Main outcome measures included rates of hospitalization for atrial fibrillation, myocardial infarction, congestive heart failure, stroke, spine and hip fractures, and rate of falls in the outpatient or inpatient setting. Hospitalizations for pneumonia were used as a negative control. RESULTS: 195,046 adults initiated treatment with L-thyroxine between 2008 and 2017: 87% generic and 13% brand formulations. They were mostly women (76%), young (94.6% under age 65), white (66%), and 47% had baseline thyroid stimulating hormone levels between 4.5 and 9.9 mIU/L. Among 35,667 propensity-matched patients, there were no significant differences between patients treated with brand versus generic L-thyroxine in atrial fibrillation (HR 0.96, 0.58-1.60), myocardial infarction (HR 0.66, 0.39-1.14), congestive heart failure (HR 1.30, 0.78-2.16), stroke (0.72, 0.49-1.06), spine (HR 0.87, 0.38-1.99) and hip fractures (HR 0.86, 0.26-2.82), or fall outcomes (HR 1.02, 0.14-7.32). Hospitalization rates for pneumonia (used as negative control) did not differ between groups (HR 0.85, 0.61-1.19). There were no interactions between brand versus generic L-thyroxine, these outcomes, and thyroid cancer, age, or L-thyroxine dose subgroups. CONCLUSIONS: We found no significant differences in cardiovascular outcomes and rates of falls and fractures for patients who filled brand versus generic L-thyroxine.

Use of Sodium-Glucose Cotransporter 2 Inhibitors in Patients With Type 1 Diabetes and Rates of Diabetic Ketoacidosis.

OBJECTIVE: To estimate real-world off-label use of sodium-glucose cotransporter 2 (SGLT2) inhibitors in patients with type 1 diabetes, estimate rates of diabetic ketoacidosis (DKA), and compare them with DKA rates observed in sotagliflozin clinical trials. RESEARCH DESIGN AND METHODS: We identified initiators of SGLT2 inhibitors in the Sentinel System from March 2013 to June 2018, determined the prevalence of type 1 diabetes using a narrow and a broad definition, and measured rates of DKA using administrative claims data. Standardized incidence ratios (SIRs) were calculated using age- and sex-specific follow-up time in Sentinel and age- and sex-specific DKA rates from sotagliflozin trials 309, 310, and 312. RESULTS: Among 475,527 initiators of SGLT2 inhibitors, 0.50% and 0.92% met narrow and broad criteria for type 1 diabetes, respectively. Rates of DKA in the narrow and broad groups were 7.3/100 person-years and 4.5/100 person-years, respectively. Among patients who met narrow criteria for type 1 diabetes, rates of DKA were highest for patients aged 25-44 years, especially females aged 25-44 years (19.7/100 person-years). More DKA events were observed during off-label use of SGLT2 inhibitors in Sentinel than would be expected based on sotagliflozin clinical trials (SIR = 1.83; 95% CI 1.45-2.28). CONCLUSIONS: Real-world off-label use of SGLT2 inhibitors among patients with type 1 diabetes accounted for a small proportion of overall SGLT2 inhibitor use. However, the risk for DKA during off-label use was notable, especially among young, female patients. Although real-word rates of DKA exceeded the expectation based on clinical trials, results should be interpreted with caution due to differences in study methods, patient samples, and study drugs.

Generic and Brand-Name Thyroid Hormone Drug Use Among Commercially Insured and Medicare Beneficiaries, 2007 Through 2016.

CONTEXT: Generic drugs account for 9 out of 10 prescriptions dispensed in the United States but for a lower proportion of commonly prescribed thyroid hormone replacement therapies. OBJECTIVE: Characterize temporal patterns of generic and brand-name thyroid hormone drug use, including patient and prescriber characteristics associated with brand-name use. DESIGN AND SETTING: Cross-sectional longitudinal analysis of national data from a large administrative claims database from January 2007 through December 2016. PATIENTS: Adults with insurance coverage through commercial, Medicare Advantage, and Medicare Part D health plans. MAIN OUTCOME MEASURES: Generic and brand-name thyroid hormone drug use. RESULTS: From 2007 to 2016, the annual number of thyroid hormone treatment pharmacy fills increased from 8,905,836 in 2007 to 11,613,923 in 2016, 73.6% of which were for generic levothyroxine, 23.4% for brand-name levothyroxine, and the remaining for other formulations. Dispensing of generic thyroid hormone drugs increased from 59.8% in 2007 to 84.9% in 2016 and was consistently higher among Medicare Advantage and Medicare Part D when compared with the commercial beneficiary population. For all three beneficiary populations, use of brand-name products was less common among older adults and more common among women and those receiving prescriptions from endocrinologists and was more common among those of white race and with greater household income for the Medicare Advantage and commercial beneficiary populations (P < 0.001). CONCLUSIONS: Brand-name thyroid hormone product use declined from 2007 to 2016 among three large, national insurer beneficiary populations. Although certain patient characteristics were associated with brand-name use, prescriber specialty was the strongest predictor.

Statin Use and Risks of Influenza-Related Outcomes Among Older Adults Receiving Standard-Dose or High-Dose Influenza Vaccines Through Medicare During 2010-2015.

Background: Statins are used to reduce cardiovascular disease risk. Recent studies suggest that statin use may be associated with an increased influenza risk among influenza vaccinees. We used Medicare data to evaluate associations between statins and risks of influenza-related encounters among vaccinees. Methods: In this retrospective cohort study, we identified Medicare beneficiaries aged > 65 years who received high-dose (HD) or standard-dose (SD) influenza vaccines at pharmacies from 2010-2011 through 2014-2015. Statin users were matched to nonusers by vaccine type, demographics, prior medical encounters, and comorbidities. We used multivariable Poisson models to estimate associations between statin use around the time of vaccination and risk of influenza-related encounters. Study outcomes included influenza-related office visits with a rapid test followed by dispensing of oseltamivir and influenza-related hospitalizations (including emergency room visits) during high influenza circulation periods. Results: The study included 1403651 statin users matched to nonusers. Cohorts were well balanced, with standardized mean differences ≤0.03 for all measured covariates. For statin users compared to nonusers, the adjusted relative risk was 1.086 (95% confidence interval [CI], 1.025-1.150) for influenza-related visits and 1.096 (95% CI, 1.013-1.185) for influenza-related hospitalizations. The risk difference ranged from ‒0.02 to 0.23 for influenza-related visits and from ‒0.04 to 0.13 for hospitalizations, depending on season severity. Results were similar for HD and SD vaccinees and for nonsynthetic and synthetic statin users. Conclusions: Among 2.8 million Medicare beneficiaries, these results suggest that statin use around the time of vaccination does not substantially affect the risk of influenza-related medical encounters among older adults.

A vaccine study design selection framework for the postlicensure rapid immunization safety monitoring program.

The Postlicensure Rapid Immunization Safety Monitoring Program, the vaccination safety monitoring component of the US Food and Drug Administration's Mini-Sentinel project, is currently the largest cohort in the US general population for vaccine safety surveillance. We developed a study design selection framework to provide a roadmap and description of methods that may be utilized to evaluate potential associations between vaccines and health outcomes of interest in the Postlicensure Rapid Immunization Safety Monitoring Program and other systems using administrative data. The strengths and weaknesses of designs for vaccine safety monitoring, including the cohort design, the case-centered design, the risk interval design, the case-control design, the self-controlled risk interval design, the self-controlled case series method, and the case-crossover design, are described and summarized in tabular form. A structured decision table is provided to aid in planning of future vaccine safety monitoring activities, and the data components comprising the structured decision table are delineated. The study design selection framework provides a starting point for planning vaccine safety evaluations using claims-based data sources.

Pilot age and geographic region of commuter and air taxi crashes: a case-control study.

BACKGROUND: Previous studies of major airline and general aviation crashes have identified a host of risk factors. We examined risk factors related to crashes involving commuter air carrier and air taxi flights. METHODS: A matched case-control design was applied to assess the association of pilot age, total flight time, and geographic region with commuter air carrier and air taxi crashes (14 CFR Part 135) from 1983-2002 in the United States. A total of 2033 commuter air carrier or air taxi crashes from the National Transportation Safety Board aviation crash database were identified as eligible cases. Controls were randomly selected incidents from the Federal Aviation Administration's (FAA) aviation incident database coded under Part 135 operation. RESULTS: Relative to controls, commuter air carrier and air taxi crashes were less likely to occur in pilots under 30 yr of age (adjusted odds ratio 0.68, 95% confidence interval 0.54-0.88) after adjusting for geographic region and total flight time. With adjustment for pilot age and total flight time, the commuter air carrier and air taxi crashes with pilot error were nearly 13 times as likely to be in Alaska as their matched controls (adjusted odds ratio 12.84, 95% confidence interval 5.24-31.45). CONCLUSIONS: These results suggest that pilot age may be associated with risk of crash involvement in Part 135 operations. The excess crash risk in Alaska with or without pilot error underscores the importance of environmental hazards in flight safety.

Pilot age and error in air taxi crashes.

INTRODUCTION: The associations of pilot error with the type of flight operations and basic weather conditions are well documented. The correlation between pilot characteristics and error is less clear. This study aims to examine whether pilot age is associated with the prevalence and patterns of pilot error in air taxi crashes. METHODS: Investigation reports from the National Transportation Safety Board for crashes involving non-scheduled Part 135 operations (i.e., air taxis) in the United States between 1983 and 2002 were reviewed to identify pilot error and other contributing factors. Crash circumstances and the presence and type of pilot error were analyzed in relation to pilot age using Chi-square tests. RESULTS: Of the 1751 air taxi crashes studied, 28% resulted from mechanical failure, 25% from loss of control at landing or takeoff, 7% from visual flight rule conditions into instrument meteorological conditions, 7% from fuel starvation, 5% from taxiing, and 28% from other causes. Crashes among older pilots were more likely to occur during the daytime rather than at night and off airport than on airport. The patterns of pilot error in air taxi crashes were similar across age groups. Of the errors identified, 27% were flawed decisions, 26% were inattentiveness, 23% mishandled aircraft kinetics, 15% mishandled wind and/or runway conditions, and 11% were others. CONCLUSIONS: Pilot age is associated with crash circumstances but not with the prevalence and patterns of pilot error in air taxi crashes. Lack of age-related differences in pilot error may be attributable to the "safe worker effect."

Crash rates of scheduled commuter and air carrier flights before and after a regulatory change.

INTRODUCTION: In 1997, in an effort to reduce the crash rate of scheduled commuter flights, the FAA required aircraft with 10-30 passenger seats to operate under stricter rules. Training and other requirements of 14 CFR Part 121 rules were applied to these midsize commuters, which previously had operated under the less strict Part 135 rules. Published crash rates obscured changes related to aircraft size. This research was undertaken to determine whether the rule change affected crash rates of aircraft with 10-30 passenger seats. METHOD: We determined the number of passenger seats on each Part 135 or Part 121 aircraft that crashed between 1983 and 2007. For aircraft with < 10, 10-30, and > 30 seats, we estimated the numbers of departures and crash rates, adjusting for changes in total departures and numbers of in-service aircraft. RESULTS: The Part 135 crash rate tripled in 1997 when commuters with 10-30 seats were excluded, reflecting the administrative change. However, the crash rate of aircraft with 10-30 passenger seats began to decline 4 yr before the rule change; thereafter, their rate was lower than for larger aircraft. The fleet size of aircraft with 10-30 passenger seats increased from 1983 to 1997, then declined as they were replaced with larger aircraft in response to the rule change. DISCUSSION: No effect of the rule change on crash rates of 10-30-seat aircraft was apparent. The decline in their crash rates began before the rule change and may have been related to the 1992 requirement for ground proximity warning devices.

Geographic region, weather, pilot age, and air carrier crashes: a case-control study.

BACKGROUND: Information about risk factors of aviation crashes is crucial for developing effective intervention programs. Previous studies assessing factors associated with crash risk were conducted primarily in general aviation, air taxis, and commuter air carriers. METHODS: A matched case-control design was used to examine the associations of geographic region, basic weather condition, and pilot age with the risk of air carrier (14 CFR Part 121) crash involvement. Cases (N = 373) were air carrier crashes involving aircraft made by Boeing, McDonnell Douglas, and Airbus recorded in the National Transportation Safety Board's aviation crash database during 1983 through 2002, and controls (N = 746) were air carrier incidents involving aircraft of the same three makes selected at random from the Federal Aviation Administration's aviation incident database. Each case was matched with two controls on the calendar year when the index crash occurred. Conditional logistic regression was used for statistical analysis. RESULTS: With adjustment for basic weather condition, pilot age, and total flight time, the risk of air carrier crashes in Alaska was more than three times the risk for other regions ladjusted odds ratio (OR) 3.18, 95% confidence interval (CI) 1.35-7.49]. Instrument meteorological conditions were associated with an increased risk for air carrier crashes involving pilot error (adjusted OR 2.26, 95% CI 1.15-4.44) and a decreased risk for air carrier crashes without pilot error (adjusted OR 0.60, 95% CI 0.37-0.96). Neither pilot age nor total flight time were significantly associated with the risk of air carrier crashes. CONCLUSIONS: The excess risk of air carrier crashes in Alaska and the effect of adverse weather on pilot-error crashes underscore the importance of environmental hazards in flight safety.

Hearing deficit in a birth cohort of U.S. male commuter air carrier and air taxi pilots.

PURPOSE: Long-term exposure to multiple risk factors in aviation may place pilots at excess risk of developing hearing deficits. We examined the incidence and risk factors for hearing deficit in a birth cohort of male commuter and air taxi pilots. METHODS: The subjects (N = 3019), who were 45-54 yr of age and held Class I medical certificates in 1987, were followed up from 1987 to 1997 through the medical certification system of the Federal Aviation Administration (FAA). In this study, hearing deficit refers to the FAA pathology code 220 (defective hearing, deafness, not elsewhere classified). Poisson regression modeling based on generalized estimation equations was used to assess the associations between pilot characteristics and the risk of developing hearing deficit. RESULTS: The 10-yr follow-up accumulated a total of 20,671 person-years and 574 incident cases of hearing deficit, yielding an incidence rate of 27.8 per 1000 person-years. Compared with age 45-49 yr, the risk of developing hearing deficit at age 50-54 yr, 55-59 yr, and 60-64 yr increased by 12% [adjusted relative risk (RR) 1.12, 95% confidence interval (CI) 0.98-1.30], 34% (RR 1.34, 95% CI 1.13-1.59), and 79% (RR 1.79, 95% CI 1.20-2.67), respectively. CONCLUSIONS: Hearing deficit is prevalent among commuter air carrier and air taxi pilots and the risk of hearing deficit increases progressively with pilot age. Effective programs for preventing excess hearing loss in the pilot population are warranted.

Pilot error in air carrier mishaps: longitudinal trends among 558 reports, 1983-2002.

BACKGROUND: Many interventions have been implemented in recent decades to reduce pilot error in flight operations. This study aims to identify longitudinal trends in the prevalence and patterns of pilot error and other factors in U.S. air carrier mishaps. METHOD: National Transportation Safety Board investigation reports were examined for 558 air carrier mishaps during 1983-2002. Pilot errors and circumstances of mishaps were described and categorized. Rates were calculated per 10 million flights. RESULTS: The overall mishap rate remained fairly stable, but the proportion of mishaps involving pilot error decreased from 42% in 1983-87 to 25% in 1998-2002, a 40% reduction. The rate of mishaps related to poor decisions declined from 6.2 to 1.8 per 10 million flights, a 71% reduction; much of this decrease was due to a 76% reduction in poor decisions related to weather. Mishandling wind or runway conditions declined by 78%. The rate of mishaps involving poor crew interaction declined by 68%. Mishaps during takeoff declined by 70%, from 5.3 to 1.6 per 10 million flights. The latter reduction was offset by an increase in mishaps while the aircraft was standing, from 2.5 to 6.0 per 10 million flights, and during pushback, which increased from 0 to 3.1 per 10 million flights. CONCLUSIONS: Reductions in pilot errors involving decision making and crew coordination are important trends that may reflect improvements in training and technological advances that facilitate good decisions. Mishaps while aircraft are standing and during pushback have increased and deserve special attention.

Age-related vision problems in commuter and air taxi pilots: a study of 3019 pilots, 1987-1997.

INTRODUCTION: Vision problems have become an increasingly important health and safety concern for pilots due to the aging of the pilot population. This paper examines the incidence of age-related vision problems in a birth cohort of commuter air carrier and air taxi pilots. METHODS: A cohort of 3019 male pilots ages 45-54 yr at baseline and holding Class I medical certificates in 1987 were retrospectively studied from 1987 to 1997 through the medical certification system of the Federal Aviation Administration. Poisson regression modeling based on generalized estimation equations was used to assess the associations of pilot characteristics with risk of developing vision problems. RESULTS: The study period accumulated 419 incident cases of vision problems, yielding an incidence of 20.3 per 1000 person-years. For pilots ages 45-49, 50-54, 55-59, and 60-64, the incidence of vision problems was 17, 20, 24, and 39 per 1000 person-years, respectively. A baseline history of eye problems and older age were each significantly associated with an increased incidence of vision problems. The adjusted relative risks of vision problems for pilot age were 1.0 (45-49 yr), 1.2 (50-54 yr), 1.4 (55-59 yr), and 3.0 (60-64 yr). The three most prevalent types of visual problems were corneal problems (16%), glaucoma (15%), and cataracts (7%). CONCLUSION: Identifying and preventing pathological changes that alter visual performance among pilots is an important component of aviation safety. With the increasing maturity of the pilot population, it is essential that appropriate visual screening and correction be emphasized for specific age-related ophthalmic conditions.

Alcohol violations and aviation accidents: findings from the U.S. mandatory alcohol testing program.

INTRODUCTION: Mandatory alcohol testing has been implemented in the U.S. aviation industry since 1995. This study documents the prevalence of alcohol violations and the association between alcohol violations and aviation accidents among aviation employees with safety-sensitive functions. METHODS: Data from the random alcohol testing and post-accident alcohol testing programs reported by major airlines to the Federal Aviation Administration for the years 1995 through 2002 were analyzed. A violation was defined as an alcohol level of > or = 0.04% or a refusal to submit to testing. Relative and attributable risks of accident involvement associated with alcohol violations were estimated using the case-control method. RESULTS: During the study period, random alcohol testing yielded a total of 440 violations, with an overall prevalence rate of 0.09% and a prevalence rate of 0.03% for flight crews. Alcohol violations were associated with an increased yet not statistically significant risk of accident involvement (odds ratio 2.56, 95% confidence interval 0.81-7.08) and were attributed to 0.13% of aviation accidents. DISCUSSION: Alcohol violations among U.S. major airline employees with safety-sensitive functions are rare and play a negligible role in aviation accidents.

Body mass index and cardiovascular disease in a birth cohort of commuter air carrier and air taxi pilots.

PURPOSE: Acute cardiovascular events such as heart attack and stroke in commercial pilots have been a concern to flight safety. The purpose of this study was to examine the association of body mass index (BMI) with cardiovascular disease in commercial pilots. METHODS: We followed from 1987 to 1997 a cohort of 3019 male commuter and air taxi pilots who were born between 1933 and 1942 and who were certified by the US Federal Aviation Administration. The relationship between BMI and the risk of cardiovascular disease was assessed using Poisson regression modeling based on generalized estimation equations. RESULTS: At baseline, 55% of the pilots were overweight (25 kg/m(2) BMI < 30 kg/m(2)) and 7% were obese (BMI >/= 30 kg/m(2)). The follow-up accumulated a total of 20,671 person-years and 1897 diagnoses of cardiovascular disease, yielding an incidence rate of 92 per 1000 person-years. The incidence rates of cardiovascular disease increased significantly with BMI. With adjustment for baseline history of cardiovascular disease and age, pilots who were overweight and obese had 6% and 22% higher risk of cardiovascular disease, respectively, than their counterparts with normal BMI. CONCLUSIONS: The prevalence of overweight/obesity and the relationship between BMI and cardiovascular disease among commercial pilots parallel findings from the general population. Incorporating BMI into the current medical standards for commercial pilots merits serious consideration.