The spring daylight saving time transition was associated with higher hazards of newly diagnosed proliferative diabetic retinopathy within 1 week and 1 month and neovascular age-related macular degeneration within 1 month compared with the summer control period, according to a nationwide retrospective cohort study of more than 12.6 million commercially insured US adults.
Investigators analyzed inpatient, outpatient, and pharmacy claims from the Merative MarketScan Commercial Database for patients aged 18 to 64 years who were enrolled for at least 1 year from 2012 to 2014. Diagnoses were identified using International Classification of Diseases, Ninth Revision codes. A 12-month lookback period was used to ensure retinal vascular diagnoses represented newly diagnosed disease rather than previously diagnosed disease.
The investigators evaluated retinal artery occlusion, retinal vein occlusion, proliferative diabetic retinopathy, and neovascular age-related macular degeneration within 1 week and 1 month following spring and autumn daylight saving time (DST) transitions. Dates in summer and winter that were equidistant from the transitions served as control periods. The winter comparison included only 2014, whereas the summer analysis included 2013 and 2014.
Kaplan-Meier analyses and Cox proportional hazards models adjusted for age, sex, year, tobacco history, cardiovascular conditions, systemic comorbidities, sleep disorders, and prior retinal disease. A robust sandwich estimator accounted for repeated observations within patients. Investigators reported Bonferroni-adjusted confidence intervals and P values to account for multiple comparisons.
The cohort had a mean age of 42 years, and 56% were female. Hypertension was recorded in 28%, hyperlipidemia in 31%, obstructive sleep apnea in 6%, diabetic retinopathy in less than 1%, and age-related macular degeneration in less than 1%.
Compared with the summer control, spring DST was associated with a 45% higher hazard of newly diagnosed proliferative diabetic retinopathy within 1 week and a 34% higher hazard within 1 month. Spring DST was also associated with a 24% higher 1-month hazard of newly diagnosed neovascular age-related macular degeneration. Autumn DST was associated with a 17% lower 1-month hazard of newly diagnosed proliferative diabetic retinopathy and a 16% lower 1-month hazard of newly diagnosed retinal vein occlusion.
“We identified a pattern where autumn and spring DST transitions were associated with decreased and increased risk of retinal vascular disease, respectively,” wrote co-first authors Kyle S. Chan of the Department of Ophthalmology at Northwestern University Feinberg School of Medicine in Chicago, Illinois, and Brian T. Cheng of the Department of Ophthalmology, Northwestern University Feinberg School of Medicine in Chicago, Illinois, and Wills Eye Hospital in Philadelphia, Pennsylvania, and colleagues.
Neither spring nor autumn DST was associated with retinal artery occlusion compared with summer.
In secondary analyses using winter as the comparator, autumn DST was associated with lower 1-week hazards of retinal vein occlusion and proliferative diabetic retinopathy and lower 1-month hazards of all four outcomes, while spring DST was not associated with any outcome.
The retrospective claims-based analysis was restricted to commercially insured adults aged 18 to 64 years and could not evaluate the effects of climate, weather, light exposure, activity levels, geographic location, race, or socioeconomic status.
The manuscript is an unedited article-in-press version and may change before final publication.
Disclosures: The study was supported by an Unrestricted Departmental Grant from Research to Prevent Blindness. The funding organization had no role in the design or conduct of the research. The investigators declared no potential competing interests.
Source: Scientific Reports