Daylight saving time transitions are not associated with increased seizure incidence

Abstract

Summary Objective Given the known association of daylight saving time (DST) transitions with increased risk of accidents, heart attack, and stroke, we aimed to determine whether seizures, which are reportedly influenced by sleep and circadian disruption, also increased in frequency following the transition into DST. Methods Using Seizure Tracker's self‐reported data from 12 401 individuals from 2008‐2016, 932 717 seizures were assessed for changes in incidence in relation to DST transitions. Two methods of standardization—z scores and unit‐scaled rate ratios (RRs)—were used to compare seizure propensities following DST transitions to other time periods. Results As a percentile relative to all other weeks in a given year, absolute seizure counts in the week of DST fell below the median (DST seizure percentiles mean ± SD: 19.68 ± 16.25, P = 0.01), which was concordant with weekday‐specific comparisons. Comparatively, RRs for whole‐week (1.06, 95% confidence interval [CI] 1.02‐1.10, P = 0.0054) and weekday‐to‐weekday (RR range 1.04‐1.16, all P < 0.001) comparisons suggested a slightly higher incidence of seizures in the DST week compared to all other weeks of the year. However, examining the similar risk of the week preceding and following the DST‐transition week revealed no significant weekday‐to‐weekday differences in seizure incidence, although there was an unexpected, modestly decreased seizure propensity in the DST week relative to the whole week prior (RR 0.94, 95% CI 0.91‐0.96, P < 0.001). Significance Despite expectations that circadian and sleep disruption related to DST transitions would increase the incidence of seizures, we found little substantive evidence for such an association in this large, longitudinal cohort. Although large‐scale observational/epidemiologic cohorts can be effective at answering such questions, additional covariates (eg, sleep duration, seizure type, and so on) that may underpin the association were not able available, so the association has not definitively been ruled out.

Short- and long-term effects of seasonal daylight saving time and Polish students’ attitude towards it

“…it is worth highlighting that each of the analyses presented above requires further observation and verification as there are sources that present different conclusions, i.e. no correlation between time changes and the increase in the number of traffic accidents, cardiovascular incidents or the effect of time changes on sleep disorders [7][8][9][10]18]. Such varying conclusions may be related to statistically significant differences between social groups, e.g.…”

“…however, newer reports contradict this theory. These disorders, if they occur, last up to 5 days after the time change, but the number of registered cases is not statistically significant [8,21]. No important change in the length of sleep nor its influence on the intensification of chronic diseases was noted.…”

“…During the following 4 days, a rise in the frequency of traffic accidents of up to 4% is observed, only to return to the baseline values on Saturday. The explanation of this phenomenon is most likely lack of sleep, rush, concentration disorders and general distraction [5,7,8]. a significant correlation between mental and behavioural disorders, chronic sleep disorders and the severity of negative symptoms after changing time has been recorded.…”