Particulate air pollution and survival in a COPD cohort

<p>Abstract</p> <p>Background</p> <p>Several studies have shown cross-sectional associations between long term exposure to particulate air pollution and survival in general population or convenience cohorts. Less is known about susceptibility, or year to year changes in exposure. We investigated whether particles were associated with survival in a cohort of persons with COPD in 34 US cities, eliminating the usual cross-sectional exposure and treating PM₁₀as a within city time varying exposure.</p> <p>Methods</p> <p>Using hospital discharge data, we constructed a cohort of persons discharged alive with chronic obstructive pulmonary disease using Medicare data between 1985 and 1999. 12-month averages of PM₁₀were merged to the individual annual follow up in each city. We applied Cox's proportional hazard regression model in each city, with adjustment for individual risk factors.</p> <p>Results</p> <p>We found significant associations in the survival analyses for single year and multiple lag exposures, with a hazard ratio for mortality for an increase of 10 μg/m³PM₁₀over the previous 4 years of 1.22 (95% CI: 1.17–1.27).</p> <p>Conclusion</p> <p>Persons discharged alive for COPD have substantial mortality risks associated with exposure to particles. The risk is evident for exposure in the previous year, and higher in a 4 year distributed lag model. These risks are significantly greater than seen in time series analyses.</p

Air pollution and general practitioner access and utilization: a population based study in Sarnia, 'Chemical Valley,' Ontario

<p>Abstract</p> <p>Background</p> <p>Health impacts of poor environmental quality have been identified in studies around the world and in Canada. While many of the studies have identified associations between air pollution and mortality or morbidity, few have focused on the role of health care as a potential moderator of impacts. This study assessed the determinants of health care access and utilization in the context of ambient air pollution in Sarnia, Ontario, Canada.</p> <p>Methods</p> <p>Residents of Sarnia participated in a Community Health Study administered by phone, while several ambient air pollutants including nitrogen dioxide (NO₂), sulphur dioxide (SO₂) and the volatile organic compounds benzene, toluene, ethylbenzene, mp- and o-xylene (BTEX) were monitored across the city. Land Use Regression models were used to estimate individual exposures to the measured pollutants and logistic regression models were utilized to assess the relative influence of environmental, socioeconomic and health related covariates on general practitioner access and utilization outcomes.</p> <p>Results</p> <p>The results show that general practitioner use increased with levels of exposure to nitrogen dioxide (NO₂- Odds Ratio [OR]: 1.16, <it>p </it>< 0.05) and sulphur dioxide (SO₂- OR: 1.61, <it>p </it>< 0.05). Low household income was a stronger predictor of having no family doctor in areas exposed to high concentrations of NO₂and SO₂. Respondents without regular care living in high pollution areas were also more likely to report travelling or waiting for care in excess of 20 minutes (OR: 3.28, <it>p </it>< 0.05) than their low exposure counterparts (OR: 1.11, <it>p </it>> 0.05).</p> <p>Conclusions</p> <p>This study provides evidence for inequitable health care access and utilization in Sarnia, with particular relevance to its situation as a sentinel high exposure environment. Levels of exposure to pollution appears to influence utilization of health care services, but poor access to primary health care services additionally burden certain groups in Sarnia, Ontario, Canada.</p

The Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort study: Assessment of environmental exposures

The Canadian Healthy Infant Longitudinal Development birth cohort was designed to elucidate interactions between environment and genetics underlying development of asthma and allergy. Over 3600 pregnant mothers were recruited from the general population in four provinces with diverse environments. The child is followed to age 5 years, with prospective characterization of diverse exposures during this critical period. Key exposure domains include indoor and outdoor air pollutants, inhalation, ingestion and dermal uptake of chemicals, mold, dampness, biological allergens, pets and pests, housing structure, and living behavior, together with infections, nutrition, psychosocial environment, and medications. Assessments of early life exposures are focused on those linked to inflammatory responses driven by the acquired and innate immune systems. Mothers complete extensive environmental questionnaires including time-activity behavior at recruitment and when the child is 3, 6, 12, 24, 30, 36, 48, and 60 months old. House dust collected during a thorough home assessment at 3–4 months, and biological specimens obtained for multiple exposure-related measurements, are archived for analyses. Geo-locations of homes and daycares and land-use regression for estimating traffic-related air pollution complement time-activity-behavior data to provide comprehensive individual exposure profiles. Several analytical frameworks are proposed to address the many interacting exposure variables and potential issues of co-linearity in this complex data set

Strength training for physical performance and injury prevention in sports. Individualised and supervised training for female athletes.

The overall purpose of this thesis was to obtain knowledge about individualised, supervised strength and conditioning programmes for physical performance and injury prevention in female athletes. Data are presented both on the influence of individualisation and supervision during resistance training for physical performance and injury prevention and on the athletes’ experience of resistance training and the role of the physical coach. Data are also presented on physical performance testing and injury prevalence and preventive action in female volleyball. Study I: The purpose of this study was to examine the prevalence of injury and the extent of preventive action in elite Swedish volleyball players. Injuries to players in the elite male and female Swedish division, during the 2002-2003 season, were registered using a questionnaire. Of the 158 volleyball players, a total of 82 players (52%) reported 121 injuries, during a total exposure time of 24,632 h. The majority of the injuries were located in the ankle, knee and back. Most injuries were classified as being of minor severity. Although most players took part in some kind of preventive action, one in every two players incurred an injury during the season, which indicates that the risk of suffering an injury in elite volleyball is relatively high. Study II: The purpose of Study II was to evaluate the test-retest reliability of sit-ups and push-ups and to investigate performance differences in muscular endurance (maximum number of repetitions) and power (timed; maximum number of repetitions in 30 s) in young women and men. Thirty-eight women and 25 men (age18-35) participated in the study. Thirteen female participants performed two test sessions of each test using a test-retest design. A high level of reliability was noted for both the sit-up and the push-up tests. There were no significant differences between the men and the women in the sit-up test, whereas the men performed significantly more push-ups than the women. Study III: The purpose of Study III was to evaluate the effects of a 26-week individualised and supervised strength and injury-prevention programme on performance enhancement. Young female volleyball players completed resistance training with either a supervised, individualised training programme (experimental group; n=10) or an unsupervised, non-individualised training programme (control group; n=17). Exposure and injury data were collected during the 2006-2007 season (baseline) and the 26-week programme with physical performance testing was carried out during the 2007-2008 season. After the intervention, the experimental group had improved significantly more (p<0.05) than the control group in the squat, barbell bench press, push-ups and sit-ups. Individualisation and supervision of resistance training seem to improve greater training adherence and strength gains compared with non-individualised and unsupervised training. Study IV: The purpose of Study IV was to explore and describe volleyball players’ experience of an individualised, supervised strength-training programme aiming at physical performance and injury prevention. The purpose was also to use the players’ observations to obtain an understanding of the role of a physical coach. The study comprised nine participants (mean age 19 years) who had been involved as the experimental group in Study III. Data were collected using semi-structured interviews and were analysed using qualitative conventional content analysis. Three overarching themes describing the content of the text emerged: 1) being in an enjoyable, relaxed situation, 2) interaction between coach and athlete and 3) mental and physical achievements. Conclusions: Individualisation and supervision appear to be of importance for compliance, strength gains and athletic performance, during strength training. From the female team athletes’ perspective, the willingness to perform strength training is dependent on team spirit, individual goal-setting and bonding with the coach. Strength training, on the one hand, could be used to improve self-esteem among young females. On the other hand, when designing strength-training intervention studies, it is important to be aware of the fear and feeling of uncertainty that may exist among the participants when it comes to strength training