Respiratory health, occupation and the healthy worker effect.

BACKGROUND: Workers are exposed to physical, chemical and other hazards in the workplace, which may impact their respiratory health. AIMS: To examine the healthy worker effect in the Canadian working population and to identify the association between occupation and respiratory health. METHODS: Data from four cycles of the Canadian Health Measures Survey were utilized. The current occupation of employed participants was classified into 10 broad categories based on National Occupation Category 2011 codes. Data relating to 15 400 subjects were analysed. RESULTS: A significantly lower proportion of those in current employment than those not in current employment reported respiratory symptoms or diseases or had airway obstruction. Similarly, those currently employed reported better general health and had greater mean values for percent-predicted forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow between 25% and 75% of FVC (FEF25-75%) and FEV1/FVC ratio. Among males, females and older age groups, significant differences were observed for almost all the respiratory outcomes for those in current employment. Those in 'Occupations unique to primary industry' had a significantly greater likelihood of regular cough with sputum and ever asthma and had lower mean values of percent-predicted FEV1/FVC and FEF25-75% than those in 'Management occupations'. Those in 'Health occupations' had the highest proportion of current asthma. CONCLUSIONS: Participants in current employment were healthier than those not in current employment providing further support for the healthy worker effect. Those in 'Occupations unique to primary industry' had an increased risk of adverse respiratory outcomes and reducing workplace exposures in these occupations has the potential to improve their respiratory health.

Indoor mold levels and current asthma among school-aged children in Saskatchewan, Canada.

Current knowledge regarding the association between indoor mold exposures and asthma is still limited. The objective of this case-control study was to investigate the relationship between objectively measured indoor mold levels and current asthma among school-aged children. Parents completed a questionnaire survey of health history and home environmental conditions. Asthma cases had a history of doctor-diagnosed asthma or current wheeze without a cold in the past 12 months. Controls were age- and sex-matched to cases. Vacuumed dust samples were collected from the child's indoor play area and mattress. Samples were assessed for mold levels and quantified in colony-forming units (CFU). Sensitization to mold allergens was also determined by skin testing. Being a case was associated with family history of asthma, pet ownership, and mold allergy. Mold levels (CFU/m2 ) in the dust samples of children's mattress and play area floors were moderately correlated (r = 0.56; P < 0.05). High mold levels (≥30 000 CFU/m2 ) in dust samples from play [adjusted odds ratio (aOR) = 2.6; 95% CI: 1.03-6.43] and mattress (aOR) = 3.0; 95% CI: 1.11-8.00) areas were significantly associated with current asthma. In this study high levels of mold are a risk factor for asthma in children.

Risk of new-onset heart failure in patients using sitagliptin: a population-based cohort study.

AIMS: To examine whether patients using sitagliptin at the time of an acute coronary syndrome event are at increased risk of incident heart failure compared with those not exposed. METHODS: Using US claims data, people with diabetes without a history of heart failure in the 3 years before hospitalization for acute coronary syndrome were identified for the period 2004 to 2010. We used a nested case-control design, whereby cases were patients who developed incident heart failure <30 days after admission to hospital for acute coronary syndrome and were matched by age and sex with up to 10 controls with no heart failure. Subjects exposed or not exposed to sitagliptin in the 90 days before acute coronary syndrome admission were compared using conditional logistic regression after adjustment for clinical and laboratory data, healthcare utilization and propensity scores. RESULTS: In total, 457 cases of heart failure developing de novo after diagnosis of acute coronary syndrome were matched to 4570 controls. The average age of the subjects was 55 years and 65% were male. Overall, 11 of 147 (7%) people exposed to sitagliptin developed heart failure compared with 446 of the 4880 people not exposed (9%, adjusted odds ratio 0.75, 95% CI 0.38-1.46; P=0.40). Sitagliptin exposure before acute coronary syndrome was not associated with an increased risk of death or heart failure combined (7% vs 9%, adjusted odds ratio 0.66, 95% CI 0.34-1.28). CONCLUSIONS: In our sample of patients who are at high risk of heart failure after acute coronary syndrome, sitagliptin exposure was not associated with an increased risk of de novo heart failure.

Effectiveness of safety-engineered devices in reducing sharp object injuries.

BACKGROUND: Sharps injuries remain a common factor in occupational exposure of healthcare workers to blood-borne viruses. The extent to which the introduction of safety-engineered devices has been effective in reducing such injuries among healthcare workers is unclear. AIMS: To investigate the incidence of sharp object injury among healthcare workers in the Capital Health Region of Alberta, Canada and to determine the effectiveness of the introduction of safety- engineered devices in preventing these. METHODS: All reports of sharp object injuries to Capital Region Workplace Health and Safety offices from healthcare workers 2003-10 were analysed. Rates of sharp object injury were compared before (2006), during (2007-08) and after (2009-10) the introduction of safety-engineered devices, adjusting for other potential risk factors using Poisson regression and log-linear models. RESULTS: Between 2003 and 2010, a total of 4707 sharp object injuries were reported from 15 healthcare facilities. The sharp object injury rate per 1000 full-time equivalent employees per year declined from 35 before the introduction period to 30 during the introduction period (rate ratio [RR]: 0.88, 95% confidence interval [CI]: 0.78, 0.99) among most healthcare workers, but then rebounded again slightly after the intervention. Physician risks showed little change during the period of introduction (odds ratio [OR]: 0.99, 95% CI: 0.85, 1.14) but decreased significantly after the intervention (OR: 0.83, 95% CI: 0.71, 0.97). CONCLUSIONS: The introduction of safety-engineered devices was associated with a modest reduction in reported sharp object injuries but this appeared to be relatively short-lived for most workers.

Ageing workers with work-related musculoskeletal injuries.

BACKGROUND: Older workers often take longer to recover and experience more missed workdays after work-related injuries, but it is unclear why or how best to intervene. Knowing the characteristics of older injured workers may help in developing interventions to reduce the likelihood of work disability. AIMS: To describe and compare several characteristics between younger and middle-aged working adults (25-54 years), adults nearing retirement (55-64 years) and adults past typical retirement (≥65 years), who sustained work-related musculoskeletal injuries. METHODS: In this cross-sectional study, Alberta workers' compensation claimants with subacute and chronic work-related musculoskeletal injuries were studied. A wide range of demographic, employment, injury and clinical characteristics were investigated. Descriptive statistics were computed and compared between the age groups. RESULTS: Among 8003 claimants, adults 65 years or older, compared to those 25-54 and 55-64 years, had lower education (16 versus 10 and 12%, P < 0.001) and were more likely to work in trades, transport and related occupations (50 versus 46 and 44%, P < 0.001), to have less offers of modified work (57 versus 39 and 42%, P < 0.001), more fractures (18 versus 14 and 11%, P < 0.001) and no further rehabilitation recommended after assessment (28 versus 18 and 20%, P < 0.01). CONCLUSIONS: Injured workers past typical retirement age appeared to be a disadvantaged group with significant challenges from a vocational rehabilitation perspective. They were less likely to have modified work options available or be offered rehabilitation, despite having more severe injuries.

Mental health in Alberta grain farmers using pesticides over many years.

BACKGROUND: Exposure to organophosphates and certain other pesticides has been related to symptoms of mental ill-health. There is particular interest in whether exposure over many years may result in chronic ill-health. AIMS: To relate lifetime history of pesticide exposure to symptoms and medical records of mental ill-health in elderly grain farmers in Alberta. METHODS: Two populations of grain farmers were identified for study: cohort A (n = 5986), members of an Alberta farm organization in 1983; cohort B (n = 4781), grain farmers registered with the provincial department of agriculture. In 2002-03 both groups completed a questionnaire on lifetime history of pesticide use, physician diagnosed disease and recent neuropsychological symptoms. Durations of exposure to seven pesticide components were calculated and a factor score extracted from responses to the symptom questionnaire. For a sub-cohort surviving to 2009 medical records for mental ill-health were identified. Records and symptom scores were related to pesticide exposures allowing for confounding. RESULTS: From cohort A, 1348 and cohort B, 1078 were alive and interviewed (median age 63 years; median duration in farming 40 years): 1371 were linked to the medical records database. Mental ill-health symptom scores were related to duration of exposure to phenoxy compounds (but not to other pesticides) and to mental ill-health in medical records. Those with mental ill-health in hospital discharge records were more likely to have been exposed to phenoxy compounds for ≥35 years. CONCLUSIONS: The relationship of long-term exposure to phenoxy herbicides and neuropsychiatric symptoms was unexpected but not explained by measured confounders.

Factors affecting work-related shoulder pain.

BACKGROUND: Work-related shoulder pain is a common problem. Ergonomic factors in the workplace are thought to be important but a number of other factors have also been associated with shoulder pain. AIMS: To identify risk factors for work-related shoulder pain in Alberta, focusing particularly on ergonomic risk factors. METHODS: A case referent design was used to compare individuals who made a Workers' Compensation Board (WCB) claim for work-related shoulder pain with individuals who made a claim for other types of injury. Data were collected using a postal questionnaire and analysed by logistic regression. RESULTS: There were 1263 participants (562 cases, 701 referents). The participation rate was 25% among cases and 21% among referents (P < 0.01). Factors associated with an increased likelihood of claim for shoulder injury included lifting ≥10 kg above shoulder height for ≥15 min per day, shoulder pain in the month prior to injury, working in the 'Government, education, and health services' industry sector and being occasionally/never satisfied with support from colleagues. CONCLUSIONS: These results support the importance of ergonomic factors in work-related shoulder pain claims, particularly the lifting of weights above shoulder level for even short periods. Relatively simple ergonomic measures, such as restricting above shoulder lifting, could be adopted with the aim of reducing the risk of shoulder injury at work.

Oxygen saturations less than 92% are associated with major adverse events in outpatients with pneumonia: a population-based cohort study.

BACKGROUND: patients with hypoxemia (blood oxygen saturation <90%) are usually hospitalized, although validated criteria (eg, the Pneumonia Severity Index [PSI]) suggest outpatient treatment is safe. We sought evidence to support or refute the practice. METHODS: all patients in Edmonton, Alberta, Canada with pneumonia assessed at any of 7 emergency departments (EDs) and then discharged were enrolled in a population-based cohort study. The independent variable of interest was oxygen saturation; the outcome was the composite endpoint of 30-day mortality or hospitalization. RESULTS: the study evaluated 2923 individuals with pneumonia who were treated as outpatients at any of 7 EDs. The patients' mean age (standard deviation [SD])was 52 (20) years; 47% were women; 74% were low risk (PSI Class I-II). The mean blood oxygen saturation (SD) was 95% (3%); 126 patients (4%) had blood oxygen saturations <90%, and 201 patients (7%) had blood oxygen saturations of 90%-92%. Over 30 days, 39 patients (1%) died and 252 (9%) reached the composite endpoint. Compared with patients with higher blood oxygen saturations, those discharged with saturations <90% had significantly (P < .001) higher rates of 30-day mortality (7 [6%] vs 32 [1%]), hospitalization (23 [18%] vs 201 [7%]), and composite endpoints (27 [21%] vs 225 [8%]). Blood oxygen saturation <90% was independently associated with 30-day mortality or hospitalization (adjusted odds ratio (OR), 1.7; 95% confidence interval (CI) 1.1-2.8; P = .032). If the saturation threshold for hospitalization was 92%, then there was no association with adverse events (adjusted OR 1.1, 95% CI 0.8-1.7, P = .48). Raising the admission threshold to 92% entails 1 additional hospitalization for every 14 patients discharged. CONCLUSIONS: among outpatients with pneumonia, oxygen saturations <90% were associated with increased morbidity and mortality. Our results indicate a hospital admission threshold of <92% would be safer and clinically better justified.

Ineffectiveness of sun awareness posters in dermatology clinics.

BACKGROUND: Although sun awareness posters have been used in doctors' offices and clinics for decades to promote sun protective behaviour, there is no evidence of their usefulness. OBJECTIVES: To investigate whether sun awareness posters lead to inquiry of skin cancer and sun protection measures. METHOD: Patients considered at risk for skin cancer seen at a dermatology clinic were randomly asked to complete a questionnaire designed to assess the effectiveness of three different sun awareness posters placed in patient rooms. The posters were selected on the basis of their catchy slogan and eye-appealing images, and included those featuring parental interest, sex appeal and informative advice. RESULTS: Only half of the patients noticed the posters (50.6%). The poster with sex appeal garnered the most attention (67.8%), followed by the informative poster (49.2%) and the parental interest poster (35.8%) (P < 0.001). Although patients who noticed the sun awareness poster inquired about cutaneous cancers and sun protection practices twice as often as those who did not notice the poster, only one-tenth of such inquiries were attributed to the poster ( approximately 5% of the target population). As reported in the questionnaire, the posters themselves were less effective than the advice of physicians in influencing patient attitudes towards sun protection measures. CONCLUSION: Organizations that produce and disseminate posters should consider beyond focus groups when they design their posters and should consider field testing their products to ensure that they are reaching the targeted audience and are having the expected beneficial effect, otherwise their posters are simply decorative.

Evaluation of associations between feed withdrawal and other management factors with Salmonella contamination of broiler chickens at slaughter in Alberta.

Salmonellosis is one of the most common bacterial foodborne diseases of public health concern in industrialized countries. Poultry products are considered an important source of Salmonella-related foodborne disease in humans. This study was undertaken to evaluate the relationship between various management factors including feed withdrawal and transportation time with Salmonella contamination in crops, ceca, and carcasses of broiler chickens at slaughter in Alberta. Using a two-stage sampling procedure, 30 matched crop and cecal samples before evisceration and an additional 30 neck skin samples after final wash of broiler chickens were collected at slaughter. A questionnaire was administered at the time of sampling to collect information on flock management risk factors. Cecal contents were individually screened with Salmonella-specific real-time PCR to detect positive flocks, and all cecal, crop, and neck skin samples from positive flocks were processed further for Salmonella isolation and characterization. The flock prevalence of Salmonella was 57.1% and within-flock prevalence of Salmonella for positive flocks was 17.2, 8.1, and 53.9% for ceca, crops, and neck skins, respectively. Salmonella Hadar was the most common serovar identified from crops, ceca, and neck skins of broiler chickens tested. Longer transport (P = 0.04 for neck skins) and waiting time in-plant (P = 0.04 for crops, P = 0.03 for ceca) were identified as important risk factors for Salmonella contamination of broiler chickens at slaughter. Salmonella contamination of broiler chickens could potentially be minimized by reducing waiting time in-plant for flocks with longer transport time.

Assessment of endotoxin levels in the home and current asthma and wheeze in school-age children.

UNLABELLED: The relationship between household endotoxin and asthma in children is not clear. To further investigate the relationship between sources of endotoxin and childhood asthma, we conducted a case-control study of children with and without asthma and examined their more frequent household exposures in the home. Children ages 6-13 years with current asthma (n = 70) or wheeze only (n = 19) were sex and age matched (+/-1 year) to 107 controls. Play area and mattress dust were collected for endotoxin analysis. Atopic status was determined by skin prick testing for allergies. A family size of >4 per household was associated with higher endotoxin levels (EU/mg) in the bed dust (P < 0.05). Passive smoking (P < 0.05) and the presence of a cat were associated with higher levels of endotoxin in mattress dust. Endotoxin levels in either the play dust or the bed dust did not differ between cases and controls. Within atopic cases, those with higher endotoxin loads (EU/m2) in bed or play areas were more likely to miss school for chest illness (P < 0.05). In this study, household endotoxin is not a risk factor for current asthma overall but may be associated with increased severity in children with atopic asthma. PRACTICAL IMPLICATIONS: This study did not find that household sources of endotoxin were associated with asthma. However, within atopic asthmatics, asthma severity (as measured by a history of being kept home from school because of a chest illness in the past year) was associated with higher levels of endotoxin in dust from the child's bed. There is a need to further investigate the nature of the relationship between household endotoxin and asthma severity in children which could lead to better management of childhood asthma.

In vitro production of tumor necrosis factor-alpha by human monocytes stimulated with lipopolysaccharide is positively correlated with increased blood monocytes after exposure to a swine barn.

Recently there has been interest in the air quality in and around intensive livestock production facilities, such as modern swine production barns, where agricultural workers and surrounding residents may be exposed to elevated levels of organic dusts. The health effects of these exposures are not completely understood. The study that is reported here is a component of a larger investigation of the relationships among the acute effects of high-concentration endotoxin exposure (swine barn dust), polymorphisms in the TLR4 gene, and respiratory outcomes following exposure to swine confinement buildings. The relationships among a mediator of acute lung inflammation, tumor necrosis factor alpha (TNF-alpha), and clinical responses to acute swine barn exposure were characterized. Analysis of the results showed that in vitro stimulation of human monocytes with as little as 1 ng/ml of lipopolysaccharide (LPS) produced a significant increase in the monocytes that produced TNF-alpha. Although the proportion of TNF-alpha-positive monocytes after in vitro stimulation with 1 ng/ml of LPS was not associated with gender or TLR4 genotype, it was positively associated with the concentration of monocytes in blood after barn exposure. Thus, these two responses to different forms of LPS exposure are significantly correlated, and more responsive monocytes in vitro indicate a forthcoming relative monocytosis, post barn exposure, which may initiate a cascade of chronic inflammation.

Prevalence of asthma and risk factors for asthma-like symptoms in Aboriginal and non-Aboriginal children in the northern territories of Canada.

BACKGROUND: Few studies have investigated the prevalence and risk factors of asthma in Canadian Aboriginal children. OBJECTIVE: To determine the prevalence of asthma and asthma-like symptoms, as well as the risk factors for asthma-like symptoms, in Aboriginal and non-Aboriginal children living in the northern territories of Canada. METHODS: Data on 2404 children, aged between 0 and 11 years, who participated in the North component of the National Longitudinal Survey of Children and Youth were used in the present study. A child was considered to have an asthma-like symptom if there was a report of ever having had asthma, asthma attacks or wheeze in the past 12 months. RESULTS: After excluding 59 children with missing information about race, 1399 children (59.7%) were of Aboriginal ancestry. The prevalence of asthma was significantly lower (P<0.05) in Aboriginal children (5.7%) than non-Aboriginal children (10.0%), while the prevalence of wheeze was similar between Aboriginal (15.0%) and non-Aboriginal (14.5%) children. In Aboriginal children, infants and toddlers had a significantly greater prevalence of asthma-like symptoms (30.0%) than preschool-aged children (21.5%) and school-aged children (11.5%). Childhood allergy and a mother's daily smoking habit were significant risk factors for asthma-like symptoms in both Aboriginal and non-Aboriginal children. In addition, infants and toddlers were at increased risk of asthma-like symptoms in Aboriginal children. In analyses restricted to specific outcomes, a mother's daily smoking habit was a significant risk factor for current wheeze in Aboriginal children and for ever having had asthma in non-Aboriginal children. CONCLUSIONS: Asthma prevalence appears to be lower in Aboriginal children than in non-Aboriginal children. The association between daily maternal smoking and asthma-like symptoms, which has been mainly reported for children living in urban areas, was observed in Aboriginal and non-Aboriginal children living in northern and remote communities in Canada.

Increasing the use of anti-inflammatory agents for acute asthma in the emergency department: experience with an asthma care map.

PURPOSE: Acute asthma is a common emergency department (ED) presentation and variation in its management is well recognized. The present study examined the use of an asthma care map (ACM) in one Canadian ED to improve adherence to acute asthma guidelines, emphasizing the use of systemic corticosteroids (SCSs) and inhaled corticosteroids (ICSs). METHODS: Three time periods were studied: the 15 months before ACM introduction (PRE), the 15 months following a three-month introduction of the ACM (POST(1)) and the 18 months after POST(1) (POST(2)). Randomly selected patient charts from each period were included from patients who were 18 to 60 years of age and presented with a primary diagnosis of acute asthma. A priori criteria were established to determine the degree of completion and success of the ACM. Primary outcomes included documentation, use of SCSs in the ED, and prescription of SCSs and ICSs at ED discharge. RESULTS: A total of 387 patient charts were included (PRE, n=150; POST(1), n=150; POST(2), n=87). Patient characteristics in the three groups were similar; however, patients in POST(1) and POST(2) showed higher use of newer agents than those in the PRE group. Overall, more women (n=209; 54%) than men were seen; the mean age was 32.4 years. The care map was used in 67% of cases during POST(1) and 70% during POST(2). The use of peak expiratory flow (PEF) was high during the PRE, POST(1) and POST(2) periods (91%, 89% and 91%, respectively); however, documentation of other markers of severity increased in the POST periods. Use of SCSs occurred earlier (P<0.01) and more often (57% PRE, 68% POST(1) and 75% POST(2); P<0.01) in the POST(1,2) periods than the PRE period. There was a significant increase in use of SCSs on discharge (55% PRE, 66% POST(1) and 69% POST(2); P<0.05), and prescription of ICSs significantly increased (24% PRE, 45% POST(1) and 61% POST(2); P<0.001) in the POST(1,2) periods. Discharge without any corticosteroids decreased over the three periods (32% PRE, 21% POST(1) and 17% POST(2); P<0.05). The length of stay in the ED increased over the study periods (181 min PRE, 209 min POST(1) and 265 min POST(2); P<0.01) and admissions were infrequent (9% PRE, 13% POST(1) and 6% POST(2); P=0.50). CONCLUSIONS: The present study provides evidence that the standardized ED ACM was widely accepted, improved chart documentation, improved some aspects of ED care and increased prescribing of discharge preventive medications.

Association between central blood pressure, arterial stiffness, and mild cognitive impairment.

BACKGROUND: To determine the relationship between central blood pressure (CBP) indices and mild cognitive impairment (MCI) in adults over the age of 50. METHODS: A cross-sectional study conducted using a non-invasive SphygmoCor XCEL device. CBP indices and brachial blood pressure were measured in 50 inpatients and outpatients. MCI was assessed using the Montreal Cognitive Assessment (MoCA) instrument and by the European Consortium Criteria (ECC). RESULTS: Seventy-six percent of subjects had hypertension, and 52% were diagnosed as having MCI using the ECC. No significant association was found between any of the measured blood pressure variables and global cognition. A significant relationship was observed between augmentation index (AI) and abnormal clock-drawing (p = 0.04) and language (p = 0.02), and between pulse pressure amplification (PPA) and language (p = 0.03). CONCLUSION: CBP indices like AI and PPA, which are markers of vascular stiffness, are associated with poor executive function and language cognitive domain deficits.

Total dust and endotoxin in poultry operations: comparison between cage and floor housing and respiratory effects in workers.

OBJECTIVE: The objective of this study was to assess respiratory outcomes and environmental exposure levels of workers in cage-housed and floor-housed poultry operations. METHODS: Poultry operations were evaluated for total dust, endotoxin, and ammonia, and respiratory symptoms and lung function tests of workers were conducted. RESULTS: Workers in floor-housed poultry operations had significantly greater exposures to total dust and ammonia, whereas workers from cage-housed poultry operations reported greater frequency of current and chronic symptoms overall and significantly greater current and chronic phlegm (39% vs 18% and 40% vs 11%, respectively). Endotoxin concentration (EU/mg) was a significant predictor (P = 0.05) of chronic phlegm for all poultry workers. CONCLUSIONS: Greater endotoxin concentration in the presence of significantly lower total dust, in conjunction with greater respiratory symptoms in workers from cage-housed poultry operations, as compared with workers from floor-housed poultry operations, appears to indicate that differences in environmental exposures may impact respiratory outcomes of workers.

Sexually inappropriate behaviour in demented elderly people.

AIM: To determine the prevalence, aetiology, and treatment profile of abnormal sexual behaviour in subjects with dementia in psychogeriatric practices. METHODS: A retrospective cross sectional study was conducted in a long term care psychiatry consultation service, community based geriatric psychiatry service, and an inpatient dementia behavioural unit in Edmonton, Canada. RESULTS: Forty one subjects (1.8%) had sexually inappropriate behaviour. Of those cognitively impaired subjects with sexually inappropriate behaviour, 20 (48.8%) were living in nursing homes and the rest, 21 (51.2%) in the community. Of these subjects, 53.7% had vascular dementia, 22% had Alzheimer's, and 9.8% had mild cognitive impairment. History of alcohol misuse and psychosis were reported in 14.6% and 9.8% of subjects respectively. Twenty seven (65.7%) had verbally inappropriate behaviour and 36 (87.8%) had physically inappropriate behaviour. In this study, verbally inappropriate behaviour was more commonly seen in the community sample (81%) than in the nursing home sample (50%) (p = 0.04). Behavioural treatment was also more commonly seen in the community sample (81%) than in the nursing home sample (45%) (p = 0.01). CONCLUSION: In this study sexually inappropriate behaviour was seen in all stages of dementia, more commonly associated with subjects of vascular aetiology, and is as commonly seen in community dwelling subjects with dementia as in nursing home subjects.

Increased asthma hospitalizations among registered Indian children and adults in Saskatchewan, 1970-1989.

We investigated asthma morbidity in children and adults among Registered Indians in Saskatchewan using hospitalization data for 1970-1989. In Registered Indians, significant increases were observed in the asthma hospitalization rates from 1979 to 1989 in boys and girls under 4 years, boys aged 5-14 years, and female adults aged 15-34 years respectively. In children under 4 years, the asthma hospitalization rates increased from 12.7 per 1000 in 1979 to 21.7 per 1000 in 1989. Asthma hospitalizations were higher among Indian boys than girls in the age group 0-4 years but this was reversed in the age groups 15-34 and 35-64 years. When compared with other Saskatchewan populations, the Indian population in age groups 0-4 and 35-64 years had significantly increased risk for hospitalization for asthma. Even though asthma was reported to be rare among Indians before 1975, we observed increases in asthma morbidity in recent years among Indian children and young adults.

Prevalence of physician-diagnosed asthma in Saskatchewan, 1981 to 1990.

STUDY OBJECTIVE: To examine trends in asthma prevalence in the Province of Saskatchewan using the Medical Claim Insurance Branch (MCIB) database. DESIGN: For each calendar year from 1981 to 1990, first visits to physicians for asthma were identified from the MCIB database. Age- and sex-specific prevalence rates were obtained for each calendar year by dividing the number of first asthma visits by the number of subjects in the age- and sex-specific group insured by the Provincial Government of Saskatchewan in that calendar year. RESULTS: Asthma prevalence increased in children and adults from 1981 to 1990. In the calendar year 1990, the prevalence of asthma was 5.1% in children < or = 4 years old, 4.4% in children 5 to 14 years old, 2.2% in young adults 15 to 34 years old, and 1.9% in adults 35 to 64 years old. Boys had higher asthma prevalence than girls in the age groups 0 to 4 years and 5 to 14 years, but it was reversed in older age groups, with women having greater asthma prevalence than men. Asthma diagnoses were verified by checking for asthma-related drug purchase in the Prescription Drug Plan database. Among the 0- to 4-year-old children with physician-diagnosed asthma, 57.3% purchased at least one asthma-related drug in 1981 and 72.3% purchased that in 1990. Among adults, asthma-related drug purchase was >73% in 1990. CONCLUSIONS: Asthma prevalence increased in children and adults in the province of Saskatchewan. Reasons for the increase are not clear and further studies are required to determine factors related to the increase.

Accelerated lung function decline in swine confinement workers.

We conducted a longitudinal study to determine the annual rate decline in pulmonary function measurements in male swine confinement workers. For comparison, a grain farming group and a nonfarming rural-dwelling control group were also chosen for the longitudinal study. Two hundred seventeen swine confinement workers, 218 grain farmers, and 179 nonfarming control subjects had valid pulmonary function measurements at the baseline observation conducted in 1990 to 1991 and at the second observation conducted in 1994 to 1995. The swine confinement workers were younger (mean age=38.3+/-11.7 [SD] years) than the nonfarming control subjects (42.6+/-10.4 years) and the grain farmers (44.5+/-11.9 years). When stratified by age, nonfarming control subjects had the lowest mean annual rate decline in FEV1 and FVC in all age categories. The swine confinement workers had the largest annual rate decline in FEV1 and FVC, and this was most obvious in the middle age categories. After controlling for age, height, smoking, and baseline pulmonary function, swine confinement workers had excess annual decline of 26.1 mL in FEV1 (p=0.0005), 33.5 mL in FVC (p=0.0002), and 42.0 mL/s in forced expiratory flow between 25% and 75% of FVC (FEF[25-75%]) (p=0.02) over nonfarming control subjects. Grain farmers had excess annual decline of 16.4 mL in FEV1 (p=0.03), 26.7 mL in FVC (p=0.002), and 11.2 mL/s in FEF(25-75%) (p=0.38) over control subjects. These findings suggest that workers engaged in the swine industry and grain farmers appear prone to accelerated yearly losses in lung function and may therefore be at risk for the future development of chronic airflow limitation.