The Influence of Daily Stress on Sedentary Behavior: Group and Person (N of 1) Level Results of a 1-Year Observational Study.

OBJECTIVE: The purpose of this study, which used mobile technologies to continuously collect data for 1 year, was to examine the association of psychological stress with objectively measured sedentary behavior in adults at both the group (e.g., nomothetic approach) and individual (e.g., idiographic approach) level. METHODS: Data were collected in an observational study of healthy adults (n = 79) residing in the New York City metro area who were studied for 365 days from 2014 to 2015. Sedentary behavior was objectively measured via accelerometry. A smartphone-based electronic diary was used to assess level of stress ("Overall, how stressful was your day?" 0-10 scale) and sources of stress. RESULTS: The end-of-day stress rating was not associated with total sedentary time (B = -1.34, p = .767) at the group level. When specific sources of stress were evaluated at the group level, argument-related stress was associated with increased sedentariness, whereas running late- and work-related stress were associated with decreased sedentariness. There was a substantial degree of interindividual variability in the relationship of stress with sedentary behavior. Both the level and sources of stress were associated with increased sedentariness for some, decreased sedentariness for others, and had no effect for many (within-person variance p < .001). CONCLUSIONS: These findings suggest that the influence of stress on sedentary behavior varies by source of stress and from person to person. A precision medicine approach may be warranted to target reductions in sedentary time, although further studies are needed to confirm the observed findings in light of study limitations including a small sample size and enrollment of participants from a single, urban metropolitan area.

Wrist-based cut-points for moderate- and vigorous-intensity physical activity for the Actical accelerometer in adults.

Wrist-based accelerometers are increasingly used to assess physical activity (PA) in population-based studies; however, cut-points to translate wrist-based accelerometer counts into PA intensity categories are still needed. The purpose of this study was to determine wrist-based cut-points for moderate- and vigorous-intensity ambulatory PA in adults for the Actical accelerometer. Healthy adults (n = 24) completed a four-phase treadmill exercise protocol (1.9, 3.0, 4.0 and 5.2 mph) while wearing an Actical accelerometer on their wrist. Metabolic equivalent of task (MET) levels were assessed by indirect calorimetry. Receiver operating characteristics (ROC) curves were generated to determine accelerometer counts that maximised sensitivity and specificity for classification of moderate (≥3 METs) and vigorous (>6 METs) ambulatory activity. The area under the ROC curves to discriminate moderate- and vigorous-intensity ambulatory activity were 0.93 (95% confidence interval [CI]: 0.90-0.97; P < 0.001) and 0.96 (95% CI: 0.94-0.99; P < 0.001), respectively. The identified cut-point for moderate-intensity ambulatory activity was 1031 counts per minute, which had a corresponding sensitivity and specificity of 85.6% and 87.5%, respectively. The identified cut-point for vigorous intensity ambulatory activity was 3589 counts per minute, which had a corresponding sensitivity and specificity of 88.0% and 98.7%, respectively. This study established intensity-specific cut-points for wrist-based wear of the Actical accelerometer which are recommended for quantification of moderate- and vigorous-intensity ambulatory activity.

How Should We Treat Depression in Patients with Cardiovascular Disease?

Among patients with cardiovascular disease (CVD), depression is highly prevalent and is associated with worse cardiovascular prognosis and lower quality of life. Treatments for depression in CVD patients produce modest, but clinically significant reductions in depressive symptoms and show promise for improving cardiovascular prognosis. While tricyclics should generally be avoided, antidepressants from multiple other classes appear to be safe in cardiac patients. A strategy of engaging patients in choosing medications or psychotherapy and then intensifying treatment to therapeutic goal appears to be more effective at reducing depression than single mode interventions. Recommendations for screening all CVD patients for depression may be premature given increased costs associated with screening and gaps in knowledge about the risk-benefit ratio of depression treatment in mild and moderately depressed patients.

Validation of the Fitbit One® for physical activity measurement at an upper torso attachment site.

BACKGROUND: The upper torso is recommended as an attachment site for the Fitbit One(®), one of the most common wireless physical activity trackers in the consumer market, and could represent a viable alternative to wrist- and hip-attachment sites. The objective of this study was to provide evidence concerning the validity of the Fitbit One(®) attached to the upper torso for measuring step counts and energy expenditure among female adults. RESULTS: Thirteen female adults completed a four-phase treadmill exercise protocol (1.9, 3.0, 4.0, and 5.2 mph). Participants were fitted with three Fitbit(®) trackers (two Fitbit One(®) trackers: one on the upper torso, one on the hip; and a wrist-based Fitbit Flex(®)). Steps were assessed by manual counting of a video recording. Energy expenditure was measured by gas exchange indirect calorimetry. Concordance correlation coefficients of Fitbit-estimated step counts to observed step counts for the upper torso-attached Fitbit One(®), hip-attached Fitbit One(®) and wrist-attached Fitbit Flex(®) were 0.98 (95% CI 0.97-0.99), 0.99 (95% CI 0.99-0.99), and 0.75 (95% CI 0.70-0.79), respectively. The percent error for step count estimates from the upper torso attachment site was ≤3% for all walking and running speeds. Upper torso step count estimates showed similar accuracy relative to hip attachment of the Fitbit One(®) and were more accurate than the wrist-based Fitbit Flex(®). Similar results were obtained for energy expenditure estimates. Energy expenditure estimates for the upper torso attachment site yielded relative percent errors that ranged from 9 to 19% and were more accurate than the wrist-based Fitbit Flex(®), but less accurate than hip attachment of the Fitbit One(®). CONCLUSIONS: Our study shows that physical activity measures obtained from the upper torso attachment site of the Fitbit One(®) are accurate across different walking and running speeds in female adults. The upper torso attachment site of the Fitbit One(®) outperformed the wrist-based Fitbit Flex(®) and yielded similar step count estimates to hip-attachment. These data support the upper torso as an alternative attachment site for the Fitbit One(®).

Diagnosing medication non-adherence in a patient with myocardial infarction.

BACKGROUND: Medication non-adherence continues to be a major challenge facing the healthcare system. A case is presented of a 48-year-old man with myocardial infarction who was found to be non-adherent to multiple medications. Conceptual models are reviewed along with current approaches for assessment and treatment of medication non-adherence. DESIGN: Case report and literature review. DISCUSSION: A theoretical model for medication non-adherence built on the Theory of Planned Behavior is presented. Empirical evidence is reviewed for determinants of non-adherent behavior such as health beliefs and self-efficacy. Current methods to assess medication non-adherence, including self-report, pill count, biological drug levels, pharmacy refill, and electronic bottles are summarized along with their limitations. Finally, an individualized approach for assessment is described using the case presented and the conceptual framework outlined above. Follow-up for the patient and potential interventions to improve medication adherence are discussed. CONCLUSION: Despite the challenges, a conceptual framework for medication non-adherence can guide assessment and treatment. Further research for innovative and effective methods to detect and treat medication non-adherence is urgently needed to aid clinicians in treating this pervasive behavioral problem.