The usability of daytime and night-time heart rate dynamics as digital biomarkers of depression severity.

BACKGROUND: Alterations in heart rate (HR) may provide new information about physiological signatures of depression severity. This 2-year study in individuals with a history of recurrent major depressive disorder (MDD) explored the intra-individual variations in HR parameters and their relationship with depression severity. METHODS: Data from 510 participants (Number of observations of the HR parameters = 6666) were collected from three centres in the Netherlands, Spain, and the UK, as a part of the remote assessment of disease and relapse-MDD study. We analysed the relationship between depression severity, assessed every 2 weeks with the Patient Health Questionnaire-8, with HR parameters in the week before the assessment, such as HR features during all day, resting periods during the day and at night, and activity periods during the day evaluated with a wrist-worn Fitbit device. Linear mixed models were used with random intercepts for participants and countries. Covariates included in the models were age, sex, BMI, smoking and alcohol consumption, antidepressant use and co-morbidities with other medical health conditions. RESULTS: Decreases in HR variation during resting periods during the day were related with an increased severity of depression both in univariate and multivariate analyses. Mean HR during resting at night was higher in participants with more severe depressive symptoms. CONCLUSIONS: Our findings demonstrate that alterations in resting HR during all day and night are associated with depression severity. These findings may provide an early warning of worsening depression symptoms which could allow clinicians to take responsive treatment measures promptly.

Organized breast cancer screening not only reduces mortality from breast cancer but also significantly decreases disability-adjusted life years: analysis of the Global Burden of Disease Study and screening programme availability in 130 countries.

BACKGROUND: Multiple studies over the past 4 decades have shown the significant benefit of breast cancer screening (BCS) in reducing mortality rates from breast cancer (BC). However, significant debate exists about the role of BCS in this regard, with some studies also showing no benefit in terms of mortality along with issues such as overdiagnosis, health care utilisation costs, psychological distress or overtreatment. To date, no BCS study has focused on disability. Hence the aim of this study is to evaluate the relative contribution of BCS approaches to age-standardized mortality and disability-adjusted life years (DALYs) rates along with other related risk factors, from a country-level perspective. PATIENTS AND METHODS: This study created a country-dataset by merging information from the Global Burden of Disease study regarding female age-standardized BC mortality, DALYs rates and other risk factors with the BCS programme availability at the national or regional level (versus no or only pilot such programme), BCS type (mammography, digital screening, breast self-examination and clinical breast examination) and other BCS-related information among 130 countries. Mixed-effect multilevel regression models were run to examine the associations of interest. RESULTS: The most important factor predictive of lower mortality was the more advanced type of BCS programme availability [mammography: -4.16, 95% CI -6.76 to -1.55; digital mammography/ultrasound: -3.64, 95% CI -6.59 to -0.70] when compared with self- or clinical breast examinations. High levels of low-density lipoprotein cholesterol (LDL-c) and smoking were also related to higher mortality and DALYs from BC. In terms of BC DALYs, BCS had a 21.9 to 22.3-fold increase in the magnitude of effect compared with that in terms of mortality. Data on mortality and DALYs in relation to BCS programmes were also calculated for high-, middle- and low-income countries. CONCLUSIONS: These data further support the positive effects of BCS in relation to age-standardized BC mortality rates, and for the first time show the impact of BCS on DALYs too. Additional factors, such as diabetes, high levels of LDL-c or smoking seemed to be related to BC mortality and disability, and could be considered as additional components of possible interventions to be used alongside BCS to optimize the BCS benefit on patients.