Just-in-Time Adaptive Intervention for Stabilizing Sleep Hours of Japanese Workers: Microrandomized Trial.

BACKGROUND: Sleep disturbance is a major contributor to future health and occupational issues. Mobile health can provide interventions that address adverse health behaviors for individuals in a vulnerable health state in real-world settings (just-in-time adaptive intervention). OBJECTIVE: This study aims to identify a subpopulation with vulnerable sleep state in daily life (study 1) and, immediately afterward, to test whether providing mobile health intervention improved habitual sleep behaviors and psychological wellness in real-world settings by conducting a microrandomized trial (study 2). METHODS: Japanese workers (n=182) were instructed to collect data on their habitual sleep behaviors and momentary symptoms (including depressive mood, anxiety, and subjective sleep quality) using digital devices in a real-world setting. In study 1, we calculated intraindividual mean and variability of sleep hours, midpoint of sleep, and sleep efficiency to characterize their habitual sleep behaviors. In study 2, we designed and conducted a sleep just-in-time adaptive intervention, which delivered objective push-type sleep feedback messages to improve their sleep hours for a subset of participants in study 1 (n=81). The feedback messages were generated based on their sleep data measured on previous nights and were randomly sent to participants with a 50% chance for each day (microrandomization). RESULTS: In study 1, we applied hierarchical clustering to dichotomize the population into 2 clusters (group A and group B) and found that group B was characterized by unstable habitual sleep behaviors (large intraindividual variabilities). In addition, linear mixed-effect models showed that the interindividual variability of sleep hours was significantly associated with depressive mood (ß=3.83; P=.004), anxiety (ß=5.70; P=.03), and subjective sleep quality (ß=-3.37; P=.03). In study 2, we found that providing sleep feedback prolonged subsequent sleep hours (increasing up to 40 min; P=.01), and this effect lasted for up to 7 days. Overall, the stability of sleep hours in study 2 was significantly improved among participants in group B compared with the participants in study 1 (P=.001). CONCLUSIONS: This is the first study to demonstrate that providing sleep feedback can benefit the modification of habitual sleep behaviors in a microrandomized trial. The findings of this study encourage the use of digitalized health intervention that uses real-time health monitoring and personalized feedback.

Development of computer adaptive testing for measuring depression in patients with cancer.

The usefulness of depression scales for patients with cancer based on item response theory (IRT) and computer adaptive testing (CAT) has not yet been fully explored. This study thus aimed to develop an IRT-based tool for measuring depression in patients with cancer. We analyzed data from 393 patients with cancer from four tertiary centers in Japan who had not received psychiatric treatment. They answered 62 questions across five categories regarding their psychiatric status over the previous week. We selected 28 items that satisfied the assumptions of IRT, fitted a graded response model to these items, and performed CAT simulations. The CAT simulation used an average of 6.96 items and showed a Pearson's correlation coefficient of 0.916 (95% confidence interval, 0.899-0.931) between the degree of depression estimated by simulation and that estimated using all 28 items. The measurement precision of CAT with only four items was superior to that of the estimation using the calibrated Patient Health Questionnaire-9. These results imply that this scale is useful and accurate for measuring depression in patients with cancer.

Outcomes of a telemedicine smoking cessation programme for heated tobacco product users in Japan: a retrospective cohort study.

OBJECTIVES: Japan is one of the largest markets for heated tobacco products (HTPs), and the number of HTP users, including dual users, is growing. However, it is not yet clear whether a telemedicine smoking cessation programme is effective for nicotine-dependent HTP users to quit smoking. We assessed the outcomes of a telemedicine smoking cessation programme in terms of continuous smoking cessation among smokers who had used HTPs compared with those who used exclusively cigarettes. DESIGN: A retrospective cohort study to assess the outcomes of the telemedicine smoking cessation programme provided by Linkage, Japan, comparing the success rates of smoking cessation between exclusively cigarette group (as reference) and HTP user groups (exclusively HTPs or dual use of both cigarettes and HTPs). SETTING: Linkage telemedicine smoking cessation programme database, covering programme participants in Japan. PARTICIPANTS: Programme participants from between August 2018 and October 2020. OUTCOME MEASURES: Continuous abstinence rates (CARs) from 9 to 24 weeks (CAR9-24) and 9 to 52 weeks (CAR9-52). Adjusted ORs (aORs) with 95% CIs for CAR were calculated to compare the exclusively cigarette group with exclusively HTP and dual use groups. RESULTS: We analysed 733 telemedicine smoking cessation programme participants. Exclusively HTP users had higher CARs than the exclusively cigarette group for CAR9-24 (aOR 1.12, 95% CI 1.02 to 1.23; p=0.02) and CAR9-52 (1.09, 0.99 to 1.19; p=0.08). Conversely, dual users had lower CARs than the exclusively cigarette group for CAR9-24 (0.85, 0.76 to 0.95; p=0.004) and CAR9-52 (0.88, 0.79 to 0.97; p=0.01). CONCLUSIONS: Exclusive HTP users achieved higher CARs, whereas dual users had lower CARs than exclusively cigarette users over short-term and long-term periods. A telemedicine smoking cessation programme may be a reasonable option for exclusive HTP users.

Autonomic dysfunction responses to head-up tilt in anorexia nervosa.

PURPOSE: Autonomic dysfunction of the cardiovascular system in anorexia nervosa (AN) was reported not only in the rest position, but also in the standing position in some previous studies, which might contribute to cardiac complications such as lethal arrhythmia. However, there has not been sufficient literature in this issue. Therefore, we performed a head-up tilt test, and compared the changes after tilting in indices of autonomic function between AN patients and healthy subjects by heart rate variability (HRV) and blood pressure variability (BPV). METHODS: The subjects were 21 females with AN and 30 age-matched healthy women. A head-up tilt test was performed following the protocol recommended by the American Heart Association. Blood pressure and heart rate data were collected for 10 min before and after tilting. In the frequency analysis, the powers of low-frequency (LF) and high-frequency (HF) components were calculated by a fast Fourier transformation. RESULTS: Regarding interactions between groups and head-up tilting, the head-up tilting-induced reduction of the HF component of HRV was significantly greater in the AN group. In addition, increases in the LF/HF of HRV and the LF component of BPV after head-up tilting were significantly smaller in the AN group. CONCLUSIONS: Regardless of the posture, changes in HF and LF/HF of HRV and LF of BPV in AN patients suggested the presence of autonomic insufficiency.

Heart rate and blood pressure variability and baroreflex sensitivity in patients with anorexia nervosa.

OBJECTIVE: Anorexia nervosa (AN) is considered to have a significant risk for sudden death because of cardiac complications, and abnormalities of the autonomic nervous system might be a cause of cardiac dysfunction. The aim of this study was to investigate autonomic nervous system function in AN patients by analyzing heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS). METHODS: The subjects were 32 AN patients without other psychiatric comorbidities and 37 healthy controls. Beat-to-beat R-R interval and systolic blood pressure recorded in the supine position were analyzed using power spectral analysis and cross-spectrum analysis to quantify the frequency domain properties of HRV, BPV, and BRS. In addition, detrended fluctuation analysis was used to quantify the fractal correlation properties from the scaling exponent alpha1 of HRV. RESULTS: High frequency power and total power of HRV and BRS were significantly higher in AN patients and low frequency power of BPV, low frequency/High frequency ratio of HRV, and the scaling exponent alpha1 of HRV were significantly lower in AN patients, compared with controls. CONCLUSIONS: These findings suggest that AN patients have reduced cardiovascular sympathetic nervous responsiveness, increased parasympathetic nervous responsiveness, and increased complexity of the interbeat interval time series compared with healthy controls. Regarding the relationship to prognosis of AN, the study showed conflicting results, and further prospective studies are needed to determine if these results are related to high mortality in AN patients.