Automated Detection of Cigarette Smoking Puffs from Mobile Sensors - A Multimodal Approach

Smoking has been conclusively proved to be the leading cause of preventable deaths in the United States. Extensive research is conducted on developing effective smoking cessation programs. Most smoking cessation programs achieve low success rate because they are unable to intervene at the right moment. Identification of high-risk situations that may lead an abstinent smoker to relapse involves discovering the associations among various contexts that precede a smoking session or a smoking lapse. In the absence of an automated method, detection of smoking events still relies on subject self-report that is prone to failure to report and involves subject burden. Automated detection of smoking events in the natural environment can revolutionize smoking research and lead to effective intervention. We investigate the feasibility of automated detection smoking puff from measurement obtained from respiratory inductive plethysmography (RIP) sensor. We introduce several new features from respiration that can help classify individual respiration cycles into smoking puffs or non-puffs. We then propose supervised and semi-supervised support vector models to detect smoking puffs. We train our models on data collected from 10 daily smokers and show that our model can still identify smoking puffs with an accuracy of 86.7%. We further show accuracy of smoking puff detection can be improved by fusing measurements from RIP and inertial sensors. We use measurements obtained from wrist worn accelerometer and gyroscope to find segments when the hand is at mouth. The segments are used to identify respiration cycles that can be potentially puff cycles. A SVM classifier is trained using 40 hours of data collected from 6 participants. The 10-fold cross validation results show that at 90.3% true positive rate, respiration feature based classifier produces on average 43.8 false positives puff per hours which is reduced to 3.7 false positives per hour when both wrist and respiration features are used. We also perform leave one subject out cross validation and show that the method generalized well

The relation of ambulatory heart rate with all-cause mortality among middle-aged men : a prospective cohort study

The aim of this study was to investigate the association between average 24-hour ambulatory heart rate and all-cause mortality, while adjusting for resting clinical heart rate, cardiorespiratory fitness, occupational and leisure time physical activity as well as classical risk factors. A group of 439 middle-aged male workers free of baseline coronary heart disease from the Belgian Physical Fitness Study was included in the analysis. Data were collected by questionnaires and clinical examinations from 1976 to 1978. All-cause mortality was collected from the national mortality registration with a mean follow-up period of 16.5 years, with a total of 48 events. After adjustment for all before mentioned confounders in a Cox proportional hazards regression analysis, a significant increased risk for all-cause mortality was found among the tertile of workers with highest average ambulatory heart rate compared to the tertile with lowest ambulatory heart rate (Hazard ratio = 3.21, 95% confidence interval: 1.22-8.44). No significant independent association was found between resting clinic heart rate and all-cause mortality. The study indicates that average 24-hour ambulatory heart rate is a strong predictor of all-cause mortality independent from resting clinic heart rate, cardiorespiratory fitness, occupational and leisure time physical activity and other classical risk factors among healthy middle-aged workers.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Brief bouts of device-measured intermittent lifestyle physical activity and its association with major adverse cardiovascular events and mortality in people who do not exercise: a prospective cohort study

BACKGROUND: Guidelines emphasise the health benefits of bouts of physical activity of any duration. However, the associations of intermittent lifestyle physical activity accumulated through non-exercise with mortality and major adverse cardiovascular events (MACE) remain unclear. We aimed to examine the associations of bouts of moderate-to-vigorous intermittent lifestyle physical activity (MV-ILPA) and the proportion of vigorous activity contributing within these bouts with mortality and MACE. METHODS: In this prospective cohort study, we used data from the UK Biobank on adults who do not exercise (ie, those who did not report leisure-time exercise) who had wrist-worn accelerometry data available. Participants were followed up until Nov 30, 2022, with the outcome of interest of all-cause mortality obtained through linkage with NHS Digital of England and Wales, and the NHS Central Register and National Records of Scotland, and MACE obtained from inpatient hospitalisation data provided by the Hospital Episode Statistics for England, the Patient Episode Database for Wales, and the Scottish Morbidity Record for Scotland. MV-ILPA bouts were derived using a two-level Random Forest classifier and grouped as short (<1 min), medium (1 to <3 min; 3 to <5 min), and long (5 to <10 min). We further examined the dose-response relationship of the proportion of vigorous physical activity contributing to the MV-ILPA bout. FINDINGS: Between June 1, 2013, and Dec 23, 2015, 103 684 Biobank participants wore an accelerometer on their wrist. 25 241 adults (mean age 61·8 years [SD 7·6]), of whom 14 178 (56·2%) were women, were included in our analysis of all-cause mortality. During a mean follow-up duration of 7·9 years (SD 0·9), 824 MACE and 1111 deaths occurred. Compared with bouts of less than 1 min, mortality risk was lower for bouts of 1 min to less than 3 min (hazard ratio [HR] 0·66 [0·53-0·81]), 3 min to less than 5 min (HR 0·56 [0·46-0·69]), and 5 to less than 10 min (HR 0·48 [0·39-0·59]). Similarly, compared with bouts of less than 1 min, risk of MACE was lower for bouts of 1 min to less than 3 min (HR 0·71 [0·54-0·93]), 3 min to less than 5 min (0·62 [0·48-0·81]), and 5 min to less than 10 min (0·59 [0·46-0·76]). Short bouts (<1 min) were associated with lower MACE risk only when bouts were comprised of at least 15% vigorous activity. INTERPRETATION: Intermittent non-exercise physical activity was associated with lower mortality and MACE. Our results support the promotion of short intermittent bouts of non-exercise physical activity of moderate-to-vigorous intensity to improve longevity and cardiovascular health among adults who do not habitually exercise in their leisure time. FUNDING: Australian National Health, Medical Research Council, and Wellcome Trust

Daily Stress Recognition from Mobile Phone Data, Weather Conditions and Individual Traits

Research has proven that stress reduces quality of life and causes many diseases. For this reason, several researchers devised stress detection systems based on physiological parameters. However, these systems require that obtrusive sensors are continuously carried by the user. In our paper, we propose an alternative approach providing evidence that daily stress can be reliably recognized based on behavioral metrics, derived from the user's mobile phone activity and from additional indicators, such as the weather conditions (data pertaining to transitory properties of the environment) and the personality traits (data concerning permanent dispositions of individuals). Our multifactorial statistical model, which is person-independent, obtains the accuracy score of 72.28% for a 2-class daily stress recognition problem. The model is efficient to implement for most of multimedia applications due to highly reduced low-dimensional feature space (32d). Moreover, we identify and discuss the indicators which have strong predictive power.Comment: ACM Multimedia 2014, November 3-7, 2014, Orlando, Florida, US

Exposure to Household Air Pollution from Biomass Cookstoves and Blood Pressure Among Women in Rural Honduras: A Cross‐Sectional Study

Growing evidence links household air pollution exposure from biomass cookstoves with elevated blood pressure. We assessed cross‐sectional associations of 24‐hour mean concentrations of personal and kitchen fine particulate matter (PM2.5), black carbon (BC), and stove type with blood pressure, adjusting for confounders, among 147 women using traditional or cleaner‐burning Justa stoves in Honduras. We investigated effect modification by age and body mass index. Traditional stove users had mean (standard deviation) personal and kitchen 24‐hour PM2.5 concentrations of 126 μg/m3 (77) and 360 μg/m3 (374), while Justa stove users’ exposures were 66 μg/m3 (38) and 137 μg/m3(194), respectively. BC concentrations were similarly lower among Justa stove users. Adjusted mean systolic blood pressure was 2.5 mm Hg higher (95% CI, 0.7‐4.3) per unit increase in natural log‐transformed kitchen PM2.5 concentration; results were stronger among women of 40 years or older (5.2 mm Hg increase, 95% CI, 2.3‐8.1). Adjusted odds of borderline high and high blood pressure (categorized) were also elevated (odds ratio = 1.5, 95% CI, 1.0‐2.3). Some results included null values and are suggestive. Results suggest that reduced household air pollution, even when concentrations exceed air quality guidelines, may help lower cardiovascular disease risk, particularly among older subgroups

Stages of health behavior change and factors associated with physical activity in patients with intermittent claudication

OBJECTIVE: To analyze, in people with intermittent claudication, the frequency of individuals who are in each of stages of health behavior change to practice physical activity, and analyze the association of these stages with the walking capacity. METHODS: We recruited 150 patients with intermittent claudication treated at a tertiary center, being included those > 30-year-old-individuals and who had ankle-arm index < 0.90. We obtained socio-demographic information, presence of comorbidities and cardiovascular risk factors and stages of health behavior change to practice physical activity through a questionnaire, they being pre-contemplation, contemplation, preparation, action and maintenance. Moreover, the walking capacity was measured in a treadmill test (Gardner protocol). RESULTS: Most individuals were in the maintenance stage (42.7%), however, when the stages of health behavior change were categorized into active (action and maintenance) and inactive (pre-contemplation, contemplation and preparation), 51.3% of the individuals were classified as inactive behavior. There was no association between stages of health behavior change, sociodemographic factors and cardiovascular risk factors. However, patients with intermittent claudication who had lower total walking distance were three times more likely to have inactive behavior. CONCLUSION: Most patients with intermittent claudication showed an inactive behavior and, in this population, lower walking capacity was associated with this behavior

Understanding respiratory illness in an HIV positive population with a high uptake of antiretroviral therapy

The availability of effective antiretroviral therapy (ART) means that HIV infection is now a manageable chronic condition. However, although AIDS-related conditions are now rare in people living with HIV (PLWH) using ART, this population may be at greater risk of some non-AIDS conditions (such as cardiovascular disease) than the general population. The respiratory health of PLWH using ART has been less well explored. This thesis provides novel insights into respiratory illness among PLWH in a population with a high uptake of antiretroviral therapy. I have summarised existing evidence in a narrative literature review of respiratory illness in PLWH and systematic review of studies comparing respiratory symptoms in people with and without HIV. I have evaluated the prevalence of respiratory illness and carriage of respiratory bacterial and viral pathogens in cross-sectional data. I used molecular microbiology techniques to explore the carriage of pathogenic respiratory bacteria in PLWH. I have completed a 12-month prospective study of a cohort of HIV positive and negative participants to determine the frequency of acute respiratory illness and factors associated with illness incidence and severity in this population. I found that respiratory symptoms are more common among HIV positive than negative people despite ART and that this difference is only partly explained by established risk factors such as tobacco smoking. In the population studied, the frequency of objective respiratory impairment as measured by spirometry was lower than that reported in many other HIV positive populations. I found no difference in the frequency of acute respiratory illnesses between HIV positive and negative individuals, however PLWH reported more severe symptoms and were more likely to seek healthcare when these illnesses occurred. In collaboration with colleagues, I have assessed interventions to improve or maintain respiratory health among PLWH. We evaluated the uptake of influenza immunisation and referral to smoking cessation services and identified barriers to these cost-effective interventions. In summary, PLWH remain at greater risk of respiratory illness than the general population despite ART. In part this is due to greater exposure to known risk factors such as tobacco smoking, but even after adjustment for these, an independent effect of HIV status remains. We need a better understanding of the causes of this and interventions to improve the respiratory health of this population

Associations between physical frailty and dementia incidence: a prospective study from UK Biobank

Background Dementia is associated with a high burden of dependency and disability. Physical frailty (hereafter referred to as frailty) is a multisystem dysregulation that has been identified as a risk factor for dementia. The aim of this study was to examine the association of frailty and its individual components with all-cause dementia incidence in a cohort of UK adults. Methods Participants in UK Biobank with data available for dementia incidence and without any form of dementia at baseline were included in this prospective study. Frailty was defined using a modified version of the frailty phenotype based on five individual components (weight loss, tiredness, physical activity, gait speed, and grip strength), with participants classified as pre-frail if they fulfilled one or two criteria or frail if they fulfilled three or more. Associations between frailty and dementia incidence were investigated using Cox proportional hazard models adjusted for sociodemographic factors, lifestyle factors, and morbidity count. The population attributable fraction was also estimated. Findings Of 502535 participants in UK Biobank, 143 215 met the inclusion criteria and were included in our analyses. 68 500 (47·8%) of the participants were pre-frail and 5565 (3·9%) were frail. During a median follow-up period of 5·4 years, 726 individuals developed dementia. Compared with non-frail individuals, the risk of dementia incidence was increased for individuals with pre-frailty (hazard ratio 1·21 [95% CI 1·04–1·42]) and frailty (1·98 [1·47–2·67]) in the fully adjusted model. Of the five components used to define frailty, weight loss (1·31 [1·09–1·58]), tiredness (1·48 [1·18–1·86]), low grip strength (1·38 [1·17–1·63]), and slow gait speed (1·55 [1·22–1·96]) were independently associated with incident dementia. Based on population attributable fraction analyses, in the study sample, pre-frailty and frailty accounted for 9·9% and 8·6% of dementia cases, respectively. Interpretation Individuals with pre-frailty and frailty were at a higher risk of dementia incidence even after adjusting for a wide range of confounding factors. Early detection and interventions for frailty could translate into prevention or delayed onset of dementia

Instrumental variable methods to assess quality of care the marginal effects of process-of-care on blood pressure change and treatment costs

Background: Hypertension is poorly controlled. Team-based care and changes in the process of care have been proposed to address these quality problems. However, assessing care processes is difficult because they are often confounded even in randomized behavioral studies by unmeasured confounders based on discretion of health care providers. Objective: To evaluate the effects of process measures including number of counseling sessions about lifestyle modification and number of antihypertensive medications on blood pressure change and payer-perspective treatment costs. Methods: Data were obtained from two prospective, cluster randomized controlled clinical trials (Trial A and B) implementing physician-pharmacist collaborative interventions compared with usual care over six months in community-based medical offices in the Midwest. Multivariate linear regression models with both instrumental variable methods and as-treated methods were utilized. Instruments were indicators for trial and study arms. Models of blood pressure change and costs included both process measures, demographic variables, and clinical variables. Results: The analysis included 496 subjects. As-treated methods showed no significant associations between process and outcomes. The instruments used in the study were insufficient to simultaneously identify distinct process effects. However, the post-hoc instrumental variable models including one process measure at a time while controlling for the other process demonstrated significant associations between the processes and outcomes with estimates considerably larger than as-treated estimates. Conclusions: Instrumental variable methods with combined randomized behavioral studies may be useful to evaluate the effects of different care processes. However, substantial distinct process variation across studies is needed to fully capitalize on this approach. Instrumental variable methods focusing on individual processes provided larger and stronger outcome relationships than those found using as-treated methods which are subject to confounding