Ascertainment Bias in a Historic Cohort Study of Residents in an Asbestos Manufacturing Community.

This paper describes follow-up for a cohort of 4530 residents living in the asbestos manufacturing community of Ambler, PA, U.S. in 1930. Using re-identified census data, cause and date of death data obtained from the genealogic website Ancestry.com, along with geospatial analysis, we explored relationships among demographic characteristics, occupational, paraoccupational and environmental asbestos exposures. We identified death data for 2430/4530 individuals. Exposure differed significantly according to race, gender, age, and recency of immigration to the U.S. Notably, there was a significant difference in the availability of year of death information for non-white vs. white individuals (odds ratio (OR) = 0.62 p-value < 0.001), females (OR = 0.53, p-value < 0.001), first-generation immigrants (OR = 0.67, p-value = 0.001), second-generation immigrants (OR = 0.31, p-value < 0.001) vs. non-immigrants, individuals aged less than 20 (OR = 0.31 p-value < 0.001) and individuals aged 20 to 59 (OR = 0.63, p-value < 0.001) vs. older individuals. Similarly, the cause of death was less often available for non-white individuals (OR = 0.42, p-value <0.001), first-generation immigrants and (OR = 0.71, p-value = 0.009), second-generation immigrants (OR = 0.49, p-value < 0.001), individuals aged less than 20 (OR = 0.028 p-value < 0.001), and individuals aged 20 to 59 (OR = 0.26, p-value < 0.001). These results identified ascertainment bias that is important to consider in analyses that investigate occupational, para-occupational and environmental asbestos exposure as risk factors for mortality in this historic cohort. While this study attempts to describe methods for assessing itemized asbestos exposure profiles for a community in 1930 using Ancestry.com and other publicly accessible databases, it also highlights how historic cohort studies likely underestimate the impact of asbestos exposure on vulnerable populations. Future work will aim to assess mortality patterns in this cohort.

IMPACT OF SWITCHING YOUTH WITH DIABETES TO INSULIN DEGLUDEC IN CLINICAL PRACTICE.

OBJECTIVE: Many youth with diabetes struggle to meet glycemic targets. The new ultralong duration of action of insulin degludec (iDeg) holds potential to ameliorate missed doses of basal insulin and improve glycemic control in youth with diabetes. METHODS: A retrospective chart review was undertaken of youth age 13 to <24 years in our practice with type 1 diabetes (T1D) or type 2 diabetes (T2D) who had been switched from glargine or detemir to iDeg to evaluate the impact of this transition on glycemic control. RESULTS: Glycated hemoglobin A1c (HbA1c) in youth with T1D (n = 82) remained stable during 6 months of treatment with iDeg (10.1 ± 2.11% [87 ± 23 mmol/mol] at start of iDeg compared to 10.1 ± 2.12% [87 ± 23 mmol/mol] at 6 months of treatment), whereas in youth with T2D (n = 16), HbA1c significantly declined from 10.6 ± 2.3% (92 ± 25 mmol/mol) to 8.3 ± 2.2% (67 ± 24 mmol/mol) ( P = .0024). CONCLUSION: In youth switched to iDeg, which in our practice is commonly due to ineffectiveness of the patient's current regimen, the outcome differences we saw may be due to preserved beta-cell function in youth with T2D. It remains to be seen whether there are benefits of transition to iDeg in youth with T1D beyond glycemic outcomes, such as reduction in ketosis and episodes of diabetic ketoacidosis. ABBREVIATIONS: DKA = diabetic ketoacidosis; DPV = Diabetes-Patienten-Verlaufsdokumentation (German/Austrian Prospective Diabetes Follow-Up Registry); HbA1c = glycated hemoglobin A1c; iDeg = insulin degludec; T1D = type 1 diabetes; T2D = type 2 diabetes.