Long day's journey into sleep.

My long day's journey into sleep began as an adolescent trying to manage my evening chronotype. The relief, I felt when my undergraduate finals were scheduled at night and as a medical student being able to select psychiatry over surgery deepened my interest in sleep and chronobiology. That interest was allowed to flourish at the National Institute of Mental Health and then at Yale Medical School in setting up a sleep laboratory. The decision to move to the University of Pittsburgh in 1973 led to a 42-year adventure in which we were able to initiate research efforts on the psychobiology of depression. Our interest in social zeitgebers (daily routines) led directly to the development and testing of a treatment intervention for mood disorders, interpersonal, and social rhythm therapy. Our continued emphasis on sleep and circadian rhythms convinced us that sleep and circadian factors were central to all of health, based on the importance of connectivity between sleep and major metabolic and cell functions. This ongoing research motivated our strong desire to study the developmental aspects of sleep. Our success was influenced immensely by the presence of young scientists and a strong subsequent interest in career mentoring. Finally, as we left Pittsburgh in 2015, we became involved in the field of continuous objective monitoring using the commercial smartphone's behavioral sensing capabilities. Our journey is not over. We hope to explore the potential of these remarkable devices to improve our understanding of sleep/wake and circadian factors across all of health.

Difference between Capillary Blood Glucose of Free Flap and the Patient: A Novel Objective Marker of Free Flap Vascular Compromise during Postoperative Monitoring.

Background Defining cut-off values of flap glucose levels in diagnosing free flap vascular compromise, without taking patients' glucose levels into account, does not hold good in all circumstances, especially in cases of high fluctuations in patients' capillary blood glucose and in diabetic patients. The aim of our study was to establish the role of capillary blood glucose measurements of the flap in relation to patients' fingertip, as an objective tool for postoperative free flap monitoring. Methods A total of 76 free flaps underwent postoperative monitoring with reference test (clinical parameters) and simultaneously with our index test (difference between capillary blood glucose of free flap and the patient), in non-diabetic and diabetic patients. Patients' demography and flap characteristics were also recorded. An ROC curve was plotted to determine diagnostic accuracy and cut-offs of the index test in diagnosing free flap vascular compromise. Results Our Index test has a cut-off value of 24.5 mg/dL with 68.75% sensitivity and 93% specificity, with an accuracy of 91.54%. Conclusion The difference between capillary blood glucose of free flap and the patient is simple, feasible, and inexpensive, and can be done by any health care professional and does not require any specialized facilities or training. It has an excellent diagnostic accuracy to detect impending free flap vascular compromise, especially in non-diabetics. Although in diabetics, this test becomes less accurate. Being an observer-independent objective test, the difference in capillary blood glucose of patient and flap measurement can be used as a highly reliable tool for postoperative free flap monitoring.

Weekday and Weekend Physical Activity of Preschool Children in Relation to Selected Socioeconomic Indicators.

Physical activity (PA) is as vital for improving the health of young children as it is positively associated with a broad range of psychological, cognitive, and cardio-metabolic outcomes. The aims of this study were to: (1) to assess the level of PA and meeting the WHO recommendations: moderate-to-vigorous physical activity (MVPA) and the number of steps in Polish preschool boys and girls on weekdays and on weekends; (2) to investigate the relationship between selected socioeconomic indicators (self-reported by parents) and PA, including meeting the WHO recommendation for daily MVPA and the number of steps on weekdays and on weekends among Polish preschoolers. Data were collected in the 2017/2018 school year. The study included a total of 522 boys and girls both aged between 5 and 6 years. The ActiGraph GT3X-BT tri-axial accelerometer was used to measure PA. Selected socioeconomic indicators as well as parental body weight and body height were self-reported by parents/caregivers using a questionnaire. In most of the PA indicators analyzed for girls (moderate, vigorous, total MVPA, and steps/day), the averages were higher during the week than during the weekend. Moreover, significantly more boys met the criteria of MVPA, both on weekdays and over the weekend (32.3% boys and 19.2% girls on weekdays and 31.1% boys and 18.1% girls on weekends). Additionally, more boys met the step recommendations, but only on weekends (15.5% boys and 6.6% girls). It was found that if there were two people in a household, there was an almost a three-fold greater chance (adj. OR = 2.94, p = 0.032) of meeting the MVPA criterion with an even stronger association (over fivefold greater chance) in meeting the step recommendation (adj. OR = 5.56, p = 0.033). The differences in the day schedule may potentially contribute with the level of PA in girls. Among the analyzed selected socioeconomic indicators, only the number of people in a household had a significant association on PA.

Objective Monitoring of Spectacle Wearing Times in Adult Subjects Using the Theramon® Thermosensor.

PURPOSE: To find a reliable method to determine the wearing times of glasses in adults objectively on the basis of temperature measurements of the small-sized theramon® thermosensor device (TM) from orthodontics. Furthermore, the reliability of the determined wearing times during well and poor position of spectacles was explored. To address the previously reported lack of accuracy during higher outside temperatures, this study was conducted in midsummer and autumn. PATIENTS AND METHODS: Twenty adults wore their spectacles with three TMs attached to both inner sides and the right outer side in a period of three consecutive days. They were asked to report wearing and non-wearing times, indoor and outdoor activities and subjective perception of spectacle position as accurately as possible. To find the most reliable way to determine spectacle wearing times compared to protocolled wearing times, we applied and evaluated temperature categorizing methods and visual analysis of time logged temperatures. Percent error and percent accuracy of each method were calculated. The methods mentioned were applied and evaluated to determine poor spectacle position. RESULTS: Median percent errors of the most reliable determination methods were <10% with an accuracy between 90% and 96%. Comparing the most reliable methods, determinations on the basis of midsummer measurements (median percent error 0% to 2%, median percent accuracy 96%) were more accurate than on the basis of autumn measurements (median percent error -5% to -20%, median percent accuracy 90%). Poor spectacle position could be determined with a median percent error of 0% and a median percent accuracy of 100% by analysing the temperature measurements of TM's visually. CONCLUSION: A reliable and objective determination of spectacle wearing times is possible on the basis of TM temperature measurements in a standard clinical setting. Measurements of one inner TM seem to be sufficient to determine the wearing times and are more appealing. Poor spectacle position can be determined reliably by analysing visually the time logged temperatures. The findings of this study require further studies on larger groups of affected, amblyopic patients and children, to analyse the real impact of spectacle wearing times and poor spectacle position on visual development.

The train-of-four or double-burst ratios cannot reliably exclude residual neuromuscular block in cats.

This study investigated the relationship between train-of-four (TOF) or double burst (DBS) ratios (T4:T1 or B2:B1) and twitch (T1) or burst (B1) magnitudes during the recovery from rocuronium-induced neuromuscular block in dogs and cats. The main hypothesis was that TOF or DBS ratios recover after the recovery of T1 or B1, and hence high ratio levels are sensitive indicators of restoration of the neuromuscular function. Six anesthetized dogs and six anesthetized cats received 0.5 mg/kg of rocuronium intravenously. The amplitudes of T1 or B1 were measured with mechanomyography during neuromuscular block until the neuromuscular function recovered fully. The TOF or DBS ratio was recorded concurrently. In dogs, recovery of T1 and B1 preceded the recovery of the TOF and DBS ratios, and T1 and B1 were always ≥90% of recovery when the respective ratio reached 0.9. In contrast, T1 was still depressed in 5/6 cats when the TOF ratio reached 0.9. At that moment, T1 was 72.5 ± 19.8% of recovery. Similarly, the DBS ratio returned to 0.9 when B1 was still <90% in 3/6 cats of recovery. The TOF and DBS fade in dogs consistently disappeared after the magnitude of T1 or B1 were restored, and hence, ratios ≥0.9 are a sensitive indicator that the neuromuscular function recovered. Our observation in cats however show that the spontaneous recovery of neither the TOF nor the DBS ratio of 0.9 can reliably exclude residual block, as the magnitude of T1 or B1 was still depressed in several instances.

Objectively Assessed Physical Activity of Preschool-Aged Children from Urban Areas.

Little is known about physical activity (PA) of preschool-age children in Poland through the course of the day. PA monitoring using an accelerometer increases the reliability of measuring daily PA levels and offers a reasonable compromise between accuracy and feasibility of measurement. The aim of the study was to determine the level of physical activity of preschool children (aged 5-6) on the basis of moderate to vigorous physical activity (MVPA) index and the number of steps. The physical activity of preschool children was assessed using accelerometery (ActiGraph) in 371 children for up to seven days. The normality of distribution was assessed using the Shapiro-Wilk test. The Mann-Whitney U-test and Kruskal-Wallis test were used to assess the significance of differences. The study group children had an average age of 5.4 years (± 0.6). Boys and girls showed a different level of MVPA index. The results significantly improve the current knowledge of PA in Europe. Promoting active lifestyles in children should be one of the health priorities in developed countries.

Effects of Vibrotactile Feedback on Sedentary Behaviors in Adults: A Pilot Randomized Controlled Trial.

No effective and easily implemented intervention strategies for reducing sedentary behavior have been established. This pilot trial (UMIN000024372) investigated whether vibrotactile feedback reduces sedentary behavior. Twenty-six adults aged 30-69 years who were sedentary ≥8 h/day were randomly assigned to control (n = 13) or vibration (n = 13) groups. Participants wore a monitor 9 h daily for seven-day periods at baseline (week zero), during the intervention (weeks one, three, five, and seven), and after the intervention (week eight). During the eight-week intervention, vibration-group participants were notified by a vibration through the monitor whenever continuous sedentary time reached ≥30 min; they also received weekly reports of their sedentary patterns. Control-group participants did not receive feedback. The primary outcome was change in total sedentary time. Changes in longer bouts of sedentary time (≥35 min) were also assessed. No significant difference was found in the change in total sedentary time (control: -17.5 min/9 h, vibration: -9.1 min/9 h; p = 0.42). Although no significant differences were observed in sedentary time in longer bouts, vibration-group participants exhibited significantly lower sedentary time (-21.6 min/9 h, p = 0.045). Thus, vibration feedback does not appear to offer any advantages in reducing total sedentary time.

Influence of short-term side effects on oral sleep appliance compliance among CPAP-intolerant patients: An objective monitoring of compliance.

OBJECTIVES: To investigate the predictive value of side effects on usage times during the initial titration phase of oral appliance therapy for sleep apnoea. The secondary objective was to assess the correlation between subjective and objective usage times. METHODS: A total of 21 subjects diagnosed with sleep apnoea and a history of non-compliance with CPAP therapy were enrolled in the 4-week clinical study. Objective compliance was assessed through an intra-oral compliance monitor embedded in a Thornton Adjustable Positioner. Subjective compliance was evaluated through self-reporting and questionnaire for side effects. RESULTS: Excess salivation, xerostomia and tooth discomfort were the most common side effects (61%-67%). Noises (OR = 10, 95% CI = 0.85-117.02, P = 0.067), jaw discomfort (OR = 15, 95% CI = 1.21-185.20, P = 0.035) and gum discomfort (OR = 8.86, 95% CI = 1.0-∞, P = 0.038) were highly predictive of non-compliance. Subjects with either "none" or "mild" side effects recorded a mean oral appliance usage time ≥5.5 hours/night, while subjects reporting "severe" side effects recorded a mean usage time ≤4 hours/night. The mean usage time was 5.49 hours/night, with nightly compliance (defined as >4 hours per night for 70% the nights per week) at 33%. Nonetheless, compliance increased from 26%-50% from week 1 to week 4. The subjective and objective usage times were highly correlated (r = 0.81). CONCLUSIONS: There was a high correlation between subjective and objective compliance reporting data. Moderate/severe side effects had the greatest effect on compliance.

Boys, older children, and highly active children benefit most from the preschool arena regarding moderate-to-vigorous physical activity: A cross-sectional study of Norwegian preschoolers.

The preschool environment exerts an important influence on children's behaviour, including physical activity (PA). However, information is lacking regarding where and when most of children's PA is undertaken. This study aimed to describe PA and sedentary time (SED) during preschool hours and time out-of-care, and on weekdays and weekend days, and to investigate differences in PA patterns according to sex, age, and MVPA levels. From September 2015 to June 2016, we measured PA levels of 1109 children (age range, 2.7-6.5 years; mean age 4.7 years; boys, 52%) using ActiGraph GT3X+ accelerometers for up to 14 consecutive days. We applied a linear mixed model to analyse associations and interactions between total PA (counts per minute [cpm]), light PA (LPA), moderate-to-vigorous PA (MVPA), SED, sex, age, and overall MVPA regardless of setting, during preschool hours versus time out-of-care, and on weekdays versus weekend days. Children undertook more PA and less SED on weekdays compared to weekend days (p < 0.01). For boys, MVPA levels were higher during preschool hours than during time out-of-care (p < 0.05). Differences in total PA and MVPA between preschool hours versus time out-of-care, and between weekdays and weekend days, were greater in boys, older children, and highly active children than in girls, younger children, and children with lower overall MVPA levels (p < 0.01). The preschool arena is important for children's PA. Concerning MVPA, this study showed that boys, older children, and highly active children benefit more from this environment compared to girls, younger preschoolers, and children with lower MVPA levels.

Physical activity among Norwegian preschoolers varies by sex, age, and season.

BACKGROUND: Knowledge of physical activity (PA) in preschool populations is important for public health promotion. We investigated levels of PA in a large sample of Norwegian preschoolers and explored variations and development in PA by sex, age, and season. METHODS: Physical activity levels of 1154 children (mean age 4.7 years, 52% boys) were measured by accelerometry (ActiGraph GT3X+) for 14 consecutive days between autumn 2015 and summer 2016. Additionally, 330 children provided up to 3 repeated measurements of PA across seasons. A linear mixed model was applied to analyze associations and interactions of total PA (cpm), light PA (LPA), moderate PA (MPA), vigorous PA (VPA), moderate-to-vigorous PA (MVPA), sedentary time (SED), sex, age, and season. RESULTS: Boys and girls spent mean (standard deviation) 72 (21) and 59 (18) min/d in MVPA and had a total PA of 790 (202) and 714 (192) cpm/d, respectively. Boys had higher PA levels than girls, PA increased with age, and PA was higher during spring/summer than autumn/winter (P < 0.001). Boys had a greater increase in PA by age than girls (P < 0.05), mainly due to increased MVPA during spring/summer (p for sex × age × season=0.009). CONCLUSIONS: Boys were consistently more active and less sedentary than girls, and PA increased with age for both sexes. Boys exhibited a greater increase than girls in PA by age, and PA differed across seasons, with higher levels of MVPA during spring/summer. Differences in MVPA between boys and girls, among age groups, and among seasons seem to be interrelated, indicating that many factors influence preschoolers' PA.

A palm-worn device to quantify rigidity in Parkinson's disease.

BACKGROUND: Parkinsonian rigidity is identified on clinical examination as resistance to passive movement. Measurement of rigidity commonly relies on ordinal rating scales (MDS-UPDRS), however instrumented objective measures may provide greater mechanistic insight. NEW METHOD: We present a palm-worn instrument to objectively quantify rigidity on a continuous scale. The device employs a miniature motor to flex the third digit of the hand about the metacarpophalangeal joint whilst transducers record flexion/extension forces. We aim to determine congruence with the MDS-UPDRS, investigate sensitivity to the impact of deep brain stimulation (DBS) and contralateral movement, and make comparisons with healthy individuals. Eight participants with Parkinson's disease underwent evaluation during conditions: on and off DBS, and with and without contralateral limb movement to activate rigidity. During each DBS condition, wash-in/out effects were tracked using both our instrument and two blinded clinical raters. Sixteen healthy volunteers (age-matched/young) served as controls. RESULTS: Rigidity measured using our instrument had moderate agreement with the MDS-UPDRS and showed differences between therapeutic state, activation conditions, and disease/healthy cohorts. Rigidity gradually worsened over a one-hour period after DBS cessation, but improved more rapidly with DBS resumption. COMPARISON WITH EXISTING METHODS: Previous attempts to quantify rigidity include manual approaches where a clinician is required to manipulate limbs while sensors passively gather information, or large automated instruments to move the wrist or elbow. CONCLUSION: Given its ability to track changes in rigidity due to therapeutic intervention, our technique could have applications where continuous measurement is required or where a suitably qualified rater is absent.

Metadata Concepts for Advancing the Use of Digital Health Technologies in Clinical Research.

Digital health technologies (smartphones, smartwatches, and other body-worn sensors) can act as novel tools to aid in the diagnosis and remote objective monitoring of an individual's disease symptoms, both in clinical care and in research. Nonetheless, such digital health technologies have yet to widely demonstrate value in clinical research due to insufficient data interpretability and lack of regulatory acceptance. Metadata, i.e., data that accompany and describe the primary data, can be utilized to better understand the context of the sensor data and can assist in data management, data sharing, and subsequent data analysis. The need for data and metadata standards for digital health technologies has been raised in academic and industry research communities and has also been noted by regulatory authorities. Therefore, to address this unmet need, we here propose a metadata set that reflects regulatory guidelines and that can serve as a conceptual map to (1) inform researchers on the metadata they should collect in digital health studies, aiming to increase the interpretability and exchangeability of their data, and (2) direct standard development organizations on how to extend their existing standards to incorporate digital health technologies. The proposed metadata set is informed by existing standards pertaining to clinical trials and medical devices, in addition to existing schemas that have supported digital health technology studies. We illustrate this specifically in the context of Parkinson's disease, as a model for a wide range of other chronic conditions for which remote monitoring would be useful in both care and science. We invite the scientific and clinical research communities to apply the proposed metadata set to ongoing and planned research. Where the proposed metadata fall short, we ask users to contribute to its ongoing revision so that an adequate degree of consensus can be maintained in a rapidly evolving technology landscape.

Evaluating the use of a temperature sensor to monitor spectacle compliance in warm versus cold climates.

BACKGROUND: This study investigates the utility of a temperature sensor data logger to monitor spectacle compliance for future application in research and clinical settings. Specifically, the question of whether warm versus cold climates negatively impact accuracy of the sensor to monitor spectacle wear is investigated. METHODS: Fifty adults from Houston, Texas (summer) and 40 adults from Columbus, Ohio (winter) wore a thermosensor on their spectacles for one week while keeping wear-time logs. Temperatures during reported spectacle wear (ON) were compared to temperatures during non-wear (OFF) between sites. Two methods to approximate wear time were evaluated by percent error with respect to subject-reported wear time. Method 1 filtered temperatures, classifying the range of 28.4 to 35.2°C as wear. Method 2 utilised examiners interpreting temperature versus time plots. Separate analysis of periods of reported outdoor wear was performed to identify the percentage of time examiners correctly identified wear. RESULTS: Group mean ON temperatures did not differ between sites (p = 0.72), but group mean OFF temperatures were significantly warmer in Houston (Houston: 24.7 ± 2.0°C, Columbus: 20.3 ± 2.1°C; p < 0.0001). Median percent error of the filtering technique to approximate subject reported wear time was 4 per cent for Houston and -8 per cent for Columbus. Median percent error for examiner 1: Houston 1 per cent, Columbus 0 per cent; median percent error for examiner 2: Houston 3 per cent, Columbus 0 per cent. Houston outdoor wear was correctly identified 88 and 97 per cent of the time by the examiners versus 79 and 81 per cent for Columbus. CONCLUSION: Despite environmental temperature differences, measured temperatures during spectacle wear were similar across subjects and median percent error was less than 10 per cent for both wear time approximation methods. The device studied was effective for objectively monitoring spectacle wear in both warm and cold climates with the caveat that subjects spent the majority of time indoors.

Validation of a precision tremor measurement system for multiple sclerosis.

BACKGROUND: Tremor is a debilitating symptom of Multiple Sclerosis (MS). Little is known about its pathophysiology and treatments are limited. Clinical trials investigating new interventions often rely on subjective clinical rating scales to provide supporting evidence of efficacy. NEW METHOD: We present a novel instrument (TREMBAL) which uses electromagnetic motion capture technology to quantify MS tremor. We aim to validate TREMBAL by comparison to clinical ratings using regression modelling with 310 samples of tremor captured from 13 MS participants who performed five different hand exercises during several follow-up visits. Minimum detectable change (MDC) and test-retest reliability were calculated and comparisons were made between MS tremor and data from 12 healthy volunteers. RESULTS: Velocity of the index finger was most congruent with clinical observation. Regression modelling combining different features, sensor configurations, and labelling exercises did not improve results. TREMBAL MDC was 84% of its initial measurement compared to 91% for the clinical rating. Intra-class correlations for test-retest reliability were 0.781 for TREMBAL and 0.703 for clinical ratings. Tremor was lower (p = 0.002) in healthy subjects. COMPARISON WITH EXISTING METHODS: Subjective scales have low sensitivity, suffer from ceiling effects, and mitigation against inter-rater variability is challenging. Inertial sensors are ubiquitous, however, their output is nonlinearly related to tremor frequency, compensation is required for gravitational artefacts, and their raw data cannot be intuitively comprehended. CONCLUSIONS: TREMBAL, compared with clinical ratings, gave measures in agreement with clinical observation, had marginally lower MDC, and similar test-retest reliability.

Child- and Parent-Related Correlates of Total and Prolonged Sedentary Time in 5- to 6-Year-Old Children.

The primary aim was to examine child- and parent-related correlates of accelerometer-assessed overall total and prolonged (i.e., accumulated in bouts of ≥10 consecutive minutes) sedentary time (SED) in 5- to 6-year-old children. Second, child- and parent-related correlates of total and prolonged SED during weekend days and the after school period were examined, as associations with parent-related correlates may be stronger during these periods. SED and moderate-to-vigorous-intensity physical activity (MVPA) were assessed by ActiGraph accelerometers in children (n = 836) and one of their parents/carers. Parents completed a questionnaire examining potential parent-related correlates. Multilevel models examined associations between potential correlates and children's total and prolonged SED. Children's MVPA was the only correlate that was consistently negatively associated with both total and prolonged SED across the different time periods (overall, after school, and weekend days). Higher total SED in parents was associated with higher overall total SED and weekend total SED in children. Higher body mass index z-scores of children were associated with lower overall total and prolonged SED. Girls had lower prolonged SED after school than boys. Older children had lower total SED during the weekend. In conclusion, few potential correlates were associated with young children's total or prolonged SED and most associations differed by time period.

Role of the Personal KinetiGraph in the routine clinical assessment of Parkinson's disease: recommendations from an expert panel.

INTRODUCTION: Evaluation of people with Parkinson's disease (PD) is often complex due to heterogeneity of symptoms and disease course, including the variability of motor fluctuations and dyskinesia. Routine clinical evaluations may be incomplete, may not accurately capture important symptoms, and may not reflect day-to-day variability. While significant advances have been made in wearable ambulatory continuous objective monitoring (COM) technologies, many clinicians remain uncertain of how to incorporate them in clinical practice, including the value to clinical decision-making. The Personal KinetiGraph™ (PKG) has FDA clearance in the United States, and has recently been used in several clinical studies. Areas covered: An expert group of movement disorders neurologists convened to discuss the clinical utility of the PKG in the routine assessment of people with PD. Based on their experience, the group identified clinical scenarios where objective information gained from review of PKG reports can provide useful information to improve clinical management. Expert commentary: PKG provides clinically meaningful data in patients with PD that can aid the clinician in evaluating patients and optimizing their pharmacologic therapy. Early clinical experience and expert opinion suggest that utilization of COM technologies such as the PKG have the potential to improve medical care in people with PD.

Children's physical activity levels during organised sports practices.

OBJECTIVES: This study measured the physical activity levels of children during practice sessions of four popular organised sports in Australia. DESIGN: Cross-sectional observational design. METHODS: Participants comprised children from four local organised sports clubs in suburban Adelaide, South Australia. The sports examined were Australian Rules Football (AFL), girls' netball, boys' soccer and girls' soccer. Each participant wore a waist-mounted GT3X or GT3X+Actigraph accelerometer in either one or two of the practice sessions. RESULTS: Participants typically spent 40-50% of each sport practice session in moderate to vigorous physical activity (MVPA). Participants in the boys' soccer teams spent significantly greater time in MVPA (mean=47% of practice time, 95% CI=37%, 57%) than participants in the girls' netball teams (mean=40%, 95% CI=30%, 50%), participants in the girls' soccer teams (mean=38%, 95% CI=28%, 48%) and participants in the boys' AFL teams (mean=40%, 95% CI=36%, 44%). The practice sessions contributed approximately half of the 60min of MVPA per day recommended by physical activity guidelines for children and young people. CONCLUSIONS: The results suggested that organised sports provide a supportive environment for physical activity accrual; however, one practice session is insufficient for children to reach the amount of MVPA recommended in daily physical activity guidelines.

Objective measurement of spectacle wear with a temperature sensor data logger.

PURPOSE: This study seeks to establish the utility of the SmartButton Data Logger (www.acrsystems.com) to monitor spectacle wear for research and clinical applications. METHODS: Fifty adults wore a thermosensor on their spectacles for 2 weeks for each of two mount types while keeping wear-time logs. Temperatures during reported spectacle wear (ON) were compared to temperatures during non-wear (OFF) with repeated measures analysis of variance (ANOVA). In addition, two strategies to approximate spectacle wear from temperature data were evaluated: (1) Filtering data based on temperature ranges to identify spectacle wear (either group mean ON temperature, or an individual's mean ON temperature), and (2) Separate examiners inspecting temperature against time plots to identify spectacle wear. The success of these methods to approximate wear time was evaluated by per cent error with respect to subject reported wear time. RESULTS: Group mean ON (31.8 [0.6]°Celsius [°C]) and OFF (24.7 [1.5]°C) temperatures differed significantly (F1,47  = 471.2, p < 0.001), but there was no difference in temperature between mounts (F1,47  = 1.9, p = 0.18). Median per cent error and first and third quartiles (Q1, Q3) of each technique used to approximate wear time were: group mean filtering = 8% (Q1 3%, Q3 18%), individual mean filtering = 7% (Q1 4%, Q3 19%), Examiner 1 = 6% (Q1 2%, Q3 14%), Examiner 2 = 7% (Q1 3%, Q3 12%). CONCLUSIONS: The SmartButton can monitor spectacle compliance in patients with all approximation methods evaluated providing less than 10% median per cent error in wear time.

Corrigendum: Analysis of Correlation between an Accelerometer-Based Algorithm for Detecting Parkinsonian Gait and UPDRS Subscales.

[This corrects the article on p. 431 in vol. 8, PMID: 28919877.].

Analysis of Correlation between an Accelerometer-Based Algorithm for Detecting Parkinsonian Gait and UPDRS Subscales.

BACKGROUND: Our group earlier developed a small monitoring device, which uses accelerometer measurements to accurately detect motor fluctuations in patients with Parkinson's (On and Off state) based on an algorithm that characterizes gait through the frequency content of strides. To further validate the algorithm, we studied the correlation of its outputs with the motor section of the Unified Parkinson's Disease Rating Scale part-III (UPDRS-III). METHOD: Seventy-five patients suffering from Parkinson's disease were asked to walk both in the Off and the On state while wearing the inertial sensor on the waist. Additionally, all patients were administered the motor section of the UPDRS in both motor phases. Tests were conducted at the patient's home. Convergence between the algorithm and the scale was evaluated by using the Spearman's correlation coefficient. RESULTS: Correlation with the UPDRS-III was moderate (rho -0.56; p < 0.001). Correlation between the algorithm outputs and the gait item in the UPDRS-III was good (rho -0.73; p < 0.001). The factorial analysis of the UPDRS-III has repeatedly shown that several of its items can be clustered under the so-called Factor 1: "axial function, balance, and gait." The correlation between the algorithm outputs and this factor of the UPDRS-III was -0.67 (p < 0.01). CONCLUSION: The correlation achieved by the algorithm with the UPDRS-III scale suggests that this algorithm might be a useful tool for monitoring patients with Parkinson's disease and motor fluctuations.