Background Increasing global urbanisation has resulted in a greater proportion of the world's population becoming exposed to risk factors unique to urban areas, and understanding these effects on public health is essential. The aim of this study was to examine the association between access to green space and mental health among adult twin pairs. Methods We used a multilevel random intercept model of same-sex twin pairs (4338 individuals) from the community-based University of Washington Twin Registry to analyse the association between access to green space, as measured by the Normalised Difference Vegetation Index and self-reported depression, stress, and anxiety. The main parameter of interest was the within-pair effect for identical (monozygotic, MZ) twins because it was not subject to confounding by genetic or shared childhood environment factors. Models were adjusted for income, physical activity, neighbourhood deprivation and population density. Results When treating twins as individuals and not as members of a twin pair, green space was significantly inversely associated with each mental health outcome. The association with depression remained significant in the within-pair MZ univariate and adjusted models; however, there was no within-pair MZ effect for stress or anxiety among the models adjusted for income and physical activity. Conclusions These results suggest that greater access to green space is associated with less depression, but provide less evidence for effects on stress or anxiety. Understanding the mechanisms linking neighbourhood characteristics to mental health has important public health implications. Future studies should combine twin designs and longitudinal data to strengthen causal inference.

Only 63% of the US population aged 50-75 years is adherent with recommended colorectal cancer (CRC) screening guidelines. Efforts are needed to increase screening for CRC. We evaluated a quality improvement intervention conducted in 2010 at Group Health in Washington State to assess the use of interactive voice response (IVR) systems to improve CRC screening. Eligible members were aged 50-81 years, received primary care from a contracted physician, and were due for CRC screening. A total of 13,279 members were identified and randomly assigned to either: (1) an intervention with IVR to encourage CRC screening (n=10,000), or (2) usual care (n=3279). The primary outcome was receipt of any recommended CRC screening test at 6 months postintervention or index date. We used Cox proportional hazards to model time until receipt of CRC screening at 6 months. Adherence to CRC screening was 10.0% in the intervention arm and 7.8% in the usual care arm at 6 months. Randomization to the IVR intervention arm was associated with a 32% increased likelihood of receiving CRC screening (hazard ratio=1.32; 95% confidence interval, 1.14, 1.52) compared with usual care. The difference in CRC screening uptake was apparent by 3 months and persisted for 12 months postintervention (log-rank test, P=0.0012). Our analysis provides "real-world" evidence that IVR is effective when delivered by a commercial health plan, and may be a useful tool for increasing adherence to screening guidelines among patients outside an integrated care practice.

Ensuring access to high-quality outpatient care is an important strategy to improve COVID-19 outcomes, reduce social inequities, and prevent potentially expensive complications of disease. This study assesses the equity of health care response to COVID-19 by examining outpatient care utilization by factors at the individual and community levels in the 12 months prior to and following COVID-19 diagnosis. Employing a retrospective, observational cohort design, we analyzed electronic health record data from a sample of 11,326 adults diagnosed with COVID-19 between March and July 2020. We used two-part models to estimate changes in use of primary and specialty care by race/ethnicity and community social vulnerability in the year before and after COVID-19 diagnosis. Our findings showed that while overall probability and counts of primary and specialty care visits increased following a positive COVID-19 diagnosis, disparities in care utilization by race/ethnicity and living in a socially vulnerable community persisted in the year that followed. These findings reiterate the need for strategic approaches to improve access to and utilization of care among those diagnosed with COVID-19, especially for individuals who are traditionally undeserved by the health system. Our findings also highlight the importance of systematic approaches for addressing social inequity in health care.