Comparison of Wearable Activity Tracker with Actigraphy for Sleep Evaluation and Circadian Rest-Activity Rhythm Measurement in Healthy Young Adults

OBJECTIVE: The purpose of this study was to evaluate the applicability of data obtained from a wearable activity tracker (Fitbit Charge HR) to medical research. This was performed by comparing the wearable activity tracker (Fitbit Charge HR) with actigraphy (Actiwatch 2) for sleep evaluation and circadian rest-activity rhythm measurement. METHODS: Sixteen healthy young adults (female participants, 62.5%; mean age, 22.8 years) wore the Fitbit Charge HR and the Actiwatch 2 on the same wrist; a sleep log was recorded over a 14-day period. We compared the sleep variables and circadian rest-activity rhythm measures with Wilcoxon signed-rank tests and Spearman's correlations. RESULTS: The periods and acrophases of the circadian rest-activity rhythms and the sleep start times did not differ and correlated significantly between the Fitbit Charge HR and the Actiwatch 2. The Fitbit Charge HR tended to overestimate the sleep durations compared with the Actiwatch 2. However, the sleep durations showed high correlation between the two devices for all days. CONCLUSION: We found that the Fitbit Charge HR showed high accuracy in sleep evaluation and circadian rest-activity rhythm measurement when compared with actigraphy for healthy young adults. The results suggest that the Fitbit Charge HR could be applicable on medical research as an alternative tool to actigraphy for sleep evaluation and measurement of the circadian rest-activity rhythm.

Effect of hospitalization on rest-activity rhythm and quality of life of cancer patients.

Rest-activity rhythm and quality of life (QoL) in three cohorts, namely (1) cancer in-patients, (2) out-patients, and (3) control subjects were studied. The patients of the former two groups were chosen randomly from the Regional Cancer Center, Raipur, India. All patients received chemotherapy for 3-4 consecutive days. The in-patients remained hospitalized for the entire period of chemotherapy plus one day post treatment. The out-patients, unlike the in-patients, went to their homes daily after treatment. Rest-activity rhythm of the patients was monitored using Actical. Quality of life (QoL) and psychological status of patients were assessed using EORTC QLQ-C30 and Hospital Anxiety & Depression Scale, respectively. Each subject exhibited significant circadian rhythm in rest-activity. The average values for Mesor, amplitude, peak activity, autocorrelation coefficient and dichotomy index of all three groups varied significantly between one group to the other in the following order: in-patient < out-patient < control. Further, quality of life, measured from responses on functional and symptom scales, was better off in cancer out-patients compared to the in-patients. It is concluded that hospitalization alters rest-activity rhythm parameters markedly and deteriorates QoL in cancer patients. Nevertheless, further extensive investigation is desirable to support the above speculation and to ascertain if hospitalization produces similar effects on patients suffering from diseases other than cancer.