Longitude-based time zone partitions and rates of suicide

Daylight saving time was not associated with a change in suicide rates in Austria, Switzerland and Sweden

BACKGROUND

Some studies have reported an increase in suicides after the start of daylight saving time (DST), but the evidence is mixed and more research about proposed mechanisms (disrupted sleep, changing light exposure) is needed.

METHODS

In our preregistered study, we analyzed change in suicide rates in the 2 weeks before/after DST, based on data between 1980 and 2022 from Austria, Switzerland and Sweden, using Poisson regression models and changepoint analyses. To explore the impact of disrupted sleep, we repeated the analysis for retired people who are likely less bound to DST, and for younger people. To explore the effect of changed daylight exposure, we repeated the analysis for northern and southern regions because twilight and daylight exposure varies by latitude.

RESULTS

Suicide rates did not significantly increase after the start of DST (adjusted incidence rate ratio IRR = 0.98, 95% CI 0.91-1.06, P = 0.66, n = 13 362 suicides) or after DST ended (adjusted IRR = 0.99, 95% CI 0.91-1.07, P = 0.76, n = 12 319 suicides). There were no statistically significant findings among younger or older subgroups and also not in Sweden and Austria/Switzerland. No changepoints were detected.

CONCLUSIONS

There were no significant changes in suicide rates associated with DST and no clear evidence to support proposed mechanisms (light exposure, disruption of sleep). Our study is one of the largest and was adequately powered. Nonetheless, even larger studies to detect smaller effects could be important to inform the debate about harms and benefits of DST.

Analyzing socio-environmental determinants of bone and soft tissue cancer in Indonesia

BACKGROUND

This study is designed to explore the potential impact of individual and environmental residential factors as risk determinants for bone and soft tissue cancers, with a particular focus on the Indonesian context. While it is widely recognized that our living environment can significantly influence cancer development, there has been a notable scarcity of research into how specific living environment characteristics relate to the risk of bone and soft tissue cancers.

METHODS

In a cross-sectional study, we analyzed the medical records of oncology patients treated at Prof. Suharso National Referral Orthopedic Hospital. The study aimed to assess tumor malignancy levels and explore the relationships with socio-environmental variables, including gender, distance from the sea, sunrise time, altitude, and population density. Data were gathered in 2020 from diverse sources, including medical records, Google Earth, and local statistical centers. The statistical analyses employed Chi-square and logistic regression techniques with the support of Predictive Analytics SoftWare (PASW) Statistics 18.

RESULTS

Both bivariate and multivariate analyses revealed two significant factors associated with the occurrence of bone and soft tissue cancer. Age exhibited a statistically significant influence (OR of 5.345 and a p-value of 0.000 < 0.05), indicating a robust connection between cancer development and age. Additionally, residing within a distance of less than 14 km from the sea significantly affected the likelihood of bone and soft tissue cancers OR 5.604 and p-value (0.001 < 0.05).

CONCLUSIONS

The study underscores the strong association between age and the development of these cancers, emphasizing the need for heightened vigilance and screening measures in older populations. Moreover, proximity to the sea emerges as another noteworthy factor influencing cancer risk, suggesting potential environmental factors at play. These results highlight the multifaceted nature of cancer causation and underscore the importance of considering socio-environmental variables when assessing cancer risk factors. Such insights can inform more targeted prevention and early detection strategies, ultimately contributing to improved cancer management and patient outcomes.