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Biomedical subjects

S M Tarlo

Publications and source records attributed to S M Tarlo.

At least 37 records · Page 2Linked to original sources
PubMed2000

Hospitalization among workers compensated for occupational asthma.

Occupational asthma (OA) can cause persistent symptoms, but populations with OA have not been followed for the development of serious outcomes such as hospitalization. Subjects receiving compensation for OA during 1980-1993, and a comparison sample of workers with musculoskeletal injuries (INJ) were identified from the Ontario Workers' Compensation Board. We also identified for comparison a group of asthmatic patients (AP) seen at a tertiary care hospital clinic during the same period. The file was matched with the Ontario Ministry of Health data base of hospitalizations through 1996. We compared the frequency of hospitalization of the subgroups with that expected in the general population using standardized morbidity ratios (SMRs), and directly by proportional hazards regression. The study group included 844 OA claimants, 1,556 INJ claimants, and 402 AP. Although admissions for all causes combined and respiratory disease among INJ were less than expected in the general population, admissions for all causes combined exceeded that expected among OA and AP. Admissions for respiratory disease were markedly greater than expected among OA (SMR 9.2) and AP (SMR 17) because of even greater excess admissions for asthma (SMRs 45 and 81, respectively). Compared with those with INJ, those with OA were more likely to be hospitalized for all causes combined (adjusted relative risk [RR] 1.4, 95% confidence interval [CI] 1.2 to 16); cardiovascular disease (RR 1.4, 95% CI 0.9 to 2.0); respiratory disease (RR 5.4, 95% CI 3.8 to 7.7); and asthma (RR 28.1, 95% CI 10.2 to 77.2) but not for malignancies (RR 1.0) or injuries (RR 0.9). Those with OA were admitted to hospital about half as frequently as AP for respiratory disease and asthma (although this was modified by smoking status and sex), but were 30% more likely to be admitted for ischemic heart disease (IHD). Among the OA claimants, factors that were significantly associated with hospitalization for asthma included older age and exposure to agents other than isocyanates. Those with OA became less likely to be hospitalized for asthma with increasing time after onset, particularly after 5 or more years. We conclude that subjects with OA suffer higher rates of hospitalizations for all causes combined, respiratory disease, and asthma than other workers, although less than among AP seen at a tertiary care center.

Adult↗
PubMed2000

Asthmatic subjects symptomatically worse at work: prevalence and characterization among a general asthma clinic population.

STUDY OBJECTIVES: To assess the prevalence of a historical occupational component to asthma in an adult asthma clinic and to compare characteristics of asthmatic subjects with and without work-attributed symptoms. DESIGN: A retrospective review of data obtained from a physician-administered questionnaire, answers to which were obtained at the initial patient visit of asthmatic subjects, and which included specific questions regarding the relationship of work to symptoms. Chart review data were used to supplement information on workplace exposures and investigations. SETTING: A university-based secondary- and tertiary-referral asthma clinic. PATIENTS: Seven hundred thirty-one adult asthmatic subjects who were referred for assessment and management of asthma. INTERVENTIONS: Statistical analyses of asthmatic subjects with and without work-attributed symptoms and a determination, from chart review, of the likelihood of causes for symptomatic worsening of asthma at work. MEASUREMENTS AND RESULTS: Sixty percent of the patients (435) had adult onset of asthma, among whom 310 patients (71%) were employed at the time of their visit. Fifty-one patients reported their asthma to be worse at work (ie, 16% of adult-onset working asthmatic subjects). Sixteen of these patients (31%) had likely or possible sensitizer-induced occupational asthma (OA), and 49% likely had aggravation of underlying asthma. The other 20% of patients had possible OA or aggravation of underlying asthma at work. CONCLUSIONS: Adult-onset asthmatic subjects commonly report a worsening of asthma at work, more commonly on the basis of likely aggravation of underlying asthma than on the basis of likely or possible OA.

Adolescent↗
PubMed2000

Prevalence and causes of cough in chronic dialysis patients: a comparison between hemodialysis and peritoneal dialysis patients.

Peritoneal dialysis (PD) and hemodialysis (HD) are both common forms of dialysis for patients with end-stage renal disease. A few case reports have suggested that cough is associated with PD. From 1991 to 1998, 17 patients being treated with PD at the Toronto Western Hospital demonstrated persistent cough severe enough for referral to a respirologist. Causes of cough, often more than one cause per patient, included asthma, post-nasal drip, gastroesophageal reflux disease (GERD), chronic obstructive pulmonary disease, congestive heart failure, allergic rhinitis, pleural effusion, and respiratory infection. The aim of this cross-sectional study was to establish the prevalence of cough among PD patients, to determine if PD patients more commonly have a dry persistent cough than do HD patients, and, if the latter case is true, the possible reasons for it. A detailed survey of 92 PD patients and 91 HD patients was conducted in 1998 and 1999 at the University Health Network. Survey questions inquired about patient respiratory symptoms since onset of dialysis. Charts were reviewed to obtain information on use of medications possibly relevant to cough. In the PD and HD groups, 52% and 23% were females (p = 0.001), and the mean ages were 59.1 and 60.1 years, respectively. Angiotensin converting enzyme (ACE) inhibitors had been taken by 65% (PD) and 55% (HD) of patients, and beta-blocking medications by 43% (PD) and 51% (HD). Since initiation of dialysis--mean 2.7 years (PD) and 3.7 years (HD)--22% of PD patients reported persistent cough versus 7% of HD patients (p = 0.003). Although no significant association was seen between cough and self-reported heartburn in HD patients (p = 0.439), a significant association between cough and self-reported heartburn was seen in PD patients: 67% of PD patients with persistent cough reported heartburn versus 29% of those without cough (p = 0.008). The findings suggest that GERD and associated cough are more common in PD patients than in HD patients, perhaps owing to increases in intra-abdominal pressure from the peritoneal dialysate.

Cough↗
PubMed1999

Isocyanate medical surveillance: respiratory referrals from a foam manufacturing plant over a five-year period.

This study assesses the causes of medical surveillance changes leading to specialist referral from one isocyanate-using company where 39 workers (about 20% of all employees) were referred to a hospital occupational clinic during a 5-year period for concerns regarding their surveillance respiratory questionnaire or spirometry results. The respiratory assessment determined that the questionnaire had detected 5 workers with non-occupational asthma, 2 with possible occupational asthma (OA), and 1 with subsequently confirmed OA, while no additional asthmatics were detected by spirometry without questionnaire findings. The surveillance questionnaire in this study was sensitive but not specific (no additional compensation claims for OA were made during this time period): workplace spirometry, however, did not add to the detection rate of asthma.

Adult↗
PubMed1999

Preliminary report of mortality among workers compensated for work-related asthma.

BACKGROUND: Although fatalities due to asthma have been reported among subjects with occupational asthma (OA) associated with re-exposure, groups of subjects with work-related asthma have not been systematically followed up for mortality. During a review of compensation claims for asthma in Ontario, we identified 3 respiratory deaths among subjects previously compensated for OA for whom their surviving spouses received death benefits. This suspected "cluster" prompted us to undertake an investigation to examine mortality pattern among workers compensated for work-related asthma. METHODS: Subjects receiving compensation for OA or aggravation of asthma (AA) between 1980 and 1993, and a comparison sample of workers with claims for musculoskeletal injuries during the same period were identified from the Ontario Workers' Compensation Board. We also identified another comparison group of non-compensated asthmatic patients seen at a hospital clinic during the same period. The files of those with work-related asthma were reviewed to determine if OA or AA was adequately documented. Mortality was ascertained by linkage with the Mortality Database at the Ontario Cancer Registry through 1996. We compared the mortality of the three groups with that expected in the general population of Ontario using SMRs, and directly by proportional-hazards regression. RESULTS: The study included 3,070 subjects: 1,112 with work-related OA/AA with adequate documentation, 1,556 with work-related injuries, and 402 patients with non-work-related asthma. Of the 66 deaths identified, only 2 deaths were due to asthma, both in the work-related asthma group: one from the index cluster and one not previously identified. A second index death was coded as dying from COPD not elsewhere classified (ICD9 496), while the third index death also died of asthma but there was not sufficient information documenting OA to include the subject in the analyses. As compared with the general population, there were fewer deaths than expected from most causes, except for deaths among the work-related asthma claimants and the nonwork-related asthma patients from respiratory diseases (SMRs 1.3 and 5.9, respectively; 0.5 among injury claimants), all chronic obstructive lung disease (ICD9 490-496; SMRs 2.3 and 7.7, respectively), and asthma (SMRs 18.2 and 0, respectively). In direct comparison of the work-related asthma claimants with the injury claimants, the risk of death appeared elevated from respiratory disease (RR 2.6) and ischemic heart disease (IHD) (RR 2.8) but the confidence intervals included unity. CONCLUSIONS: This preliminary report raises the possibility that serious outcomes, including excess deaths from respiratory disease, in particular asthma, may occur among those with work-related asthma even in the absence of re-exposure. However, the findings are inconclusive given that the number of deaths was small and we identified only one new asthma death in addition to the index cluster. We also observed for the first time that deaths due to circulatory disease, particularly IHD, may also be increased among such workers; this needs to be confirmed elsewhere.

Adult↗
PubMed1999

The outcome of asthma related to workplace irritant exposures: a comparison of irritant-induced asthma and irritant aggravation of asthma.

STUDY OBJECTIVES: (1) To characterize workers' compensation claims accepted on the basis of new-onset asthma associated with accidental high respiratory irritant exposure at work; (2) to compare the frequency, characteristics, and outcomes in this group of workers to workers who were compensated for an exacerbation of preexisting asthma associated with accidental high respiratory irritant exposure at work. DESIGN: A retrospective review was performed of 469 asthma claims accepted by the Ontario Workers' Compensation Board (WCB) between 1984 and 1988. Among these, claims attributed to an accidental high respiratory irritant exposure at work were classified into two groups: one group with reported preexisting asthma prior to the exposure (accidental aggravation of asthma [AAA]) and another group with no previous history of asthma (irritant-induced asthma [IIA]). RESULTS: Of the 469 claims, 89 subjects (19%) had symptoms related to accidental high respiratory irritant exposure in the workplace; of these, 68 subjects (76%) had AAA, 12 subjects (13%) had IIA, and 9 subjects (10%) had possible IIA but were excluded from the analysis because of insufficient data. Those with IIA had a longer duration of work-attributed symptoms (mean, 219 +/- 208 days) than the subjects with AAA (mean, 32 +/- 38 days; p < 0.001). Nine subjects (75%) with IIA were no longer in the same work environment, while 47 subjects in the AAA group (71%) were still in the same work environment (p < 0.001). The most common triggering agent for subjects with IIA was an isocyanate spill; for those with AAA, the most common triggering agent was paint. CONCLUSIONS: The WCB-accepted claims related to accidental, high respiratory irritant exposure at work are more commonly assigned to the category of AAA than to IIA. IIA patients in this claimant group had a longer mean duration of work-attributed respiratory symptoms, perhaps due to a need for a larger (and thus less common) irritant exposure to induce asthma in previously normal subjects.

Adult↗
PubMed1999

Occupational allergies and asthma.

OBJECTIVE: To review aspects of occupational allergies and asthma for primary care physicians recognizing, diagnosing, and managing patients with these conditions. QUALITY OF EVIDENCE: Studies in the medical literature mainly provide level 2 evidence, that is, from at least one well-designed clinical trial without randomization, from cohort or case-control analytical studies, from multiple time series, or from dramatic results in uncontrolled experiments. MAIN MESSAGE: Occupational allergies and asthma have the best prognosis with an early, accurate diagnosis and subsequent avoidance of exposure to the relevant sensitizer. These diagnoses can normally be suspected from the clinical history. Primary care physicians can also initiate investigations to make an objective diagnosis, can assess workplace exposure agents from the history, and can review appropriate data sheets on material safety. Specialist evaluation is likely to be needed for skin tests, however, and for other specialized tests (such as pulmonary function assessments at work and off work or specific challenges with the suspected workplace agent). Patients with a confirmed diagnosis need appropriate medical management of their allergic manifestations or asthma, but also often require psychosocial support during the period of investigation and management, especially in relation to required changes in their work and to compensation or insurance claims. CONCLUSIONS: Consider workplace exposure as a source of patients' allergies or asthma and aim to make an early, accurate diagnosis.

Asthma↗
PubMed1998

Effect of exposure to low levels of ozone on the response to inhaled allergen in allergic asthmatic patients.

STUDY OBJECTIVES: In a previous study published by our group, six out of nine subjects with mild allergic asthma were shown to have an enhanced response to allergen challenge following a 1-h exposure in an 0.8-m3 exposure chamber (modified from a body plethysmograph) to an average of 120 parts per billion (ppb) ozone at rest. Other studies failed to confirm this effect. In the present study, using a similar design, we reexamined this effect using a larger group of asthmatics and a larger chamber allowing minimal fluctuations in ozone levels during exposures. DESIGN: Prospective, randomized single-blinded crossover study. SETTING: Pulmonary function laboratory equipped with an exposure chamber. SUBJECTS: Fifteen subjects had mild allergic asthma; 9 men and 6 women; the mean (SD) age was 32.5 (10) years; FEV1 was 3.4 (0.8) L; baseline methacholine provocation concentration causing a 20% fall in FEV1 was (PC20) 3.28 (4.1) mg/mL. INTERVENTIONS: Each participant was exposed, at rest, on 1 day to filtered air and on another day to ozone (mean level=120 ppb) in a larger exposure chamber than the one used in our first study with less variability in ozone level (110 to 130 vs 85 to 175 ppb) using a random, single-blinded design. After each exposure, the subject was challenged with allergen (nine with grass pollen extract and six with ragweed extract) and allergen PC15 was measured. RESULTS: Ozone preexposure did not affect allergen PC15 when compared with clean air preexposure (allergen PC15 dilution 1/114 vs 1/119, respectively). Ozone vs air preexposure resulted in an allergen PC15 that was lower in five subjects, higher in six, and unchanged (within one doubling dose) in four. CONCLUSIONS: At this low level with less variability and lower peaks than our previous study, ozone had no significant effect on airway allergen responsiveness.

Administration, Inhalation↗
PubMed1998

Latex allergy: a problem for both healthcare professionals and patients.

Immediate hypersensitivity responses to natural rubber latex (NRL) products have been recognized with increasing frequency in North America since 1989. The allergic response occurs to one or more NRL proteins, resulting in contact urticaria, angioedema, allergic rhinitis, asthma, or anaphylaxis. Early recognition of sensitization to NRL is crucial to prevent the occurrence of life-threatening reactions in sensitized healthcare providers and their patients.

Education, Nursing, Continuing↗
PubMed1997

Assessment of the relationship between isocyanate exposure levels and occupational asthma.

As part of a previous study, we identified Ontario cases of isocyanate-induced occupational asthma (OA) and the companies at which they worked. The Ontario Ministry of Labour maintained a computerized database including isocyanate air sampling determinations conducted by the Ministry. Within this database, we compared levels of isocyanate concentrations measured at 20 case companies [with compensated isocyanate asthma (OA) claims] with 203 noncase companies, based on air samples collected during the same 4-year period during which the OA claims arose. The proportion of case companies that were ever recorded as having a measured ambient isocyanate concentration of > or = 0.005 ppm was greater than that for noncase companies, for TDI users (43% vs 22%), and for MDI users (40% vs 27%). This reached conventional significance when combined across companies and isocyanate types (50% vs 25%; P < 0.05). This provides some evidence that facilities having OA claims have higher isocyanate exposures than do those without claims.

Air Pollutants↗
PubMed1997

Latex sensitivity in dental students and staff: a cross-sectional study.

BACKGROUND: Dental practitioners, like other health care providers who regularly use latex gloves, are at increased risk for latex sensitivity. They are also at risk for irritant or allergic contact dermatitis. OBJECTIVE: This study was carried out to determine the prevalence of latex sensitivity and possible risk factors in staff and students of a Faculty of Dentistry. METHODS: A cross-sectional study was performed by using a questionnaire and allergy skin prick testing. RESULTS: Two hundred three students and staff members completed the questionnaire. Five percent reported asthma symptoms on exposure to rubber products, 13% reported symptoms of rhinitis or conjunctivitis, and 17% reported pruritus or urticaria within minutes of exposure to rubber. Overall, 10% of 131 subjects who underwent skin prick tests had a positive response to natural rubber latex. Among the students tested, there were increasing percentages of positive skin test responses to latex with increasing years of study (0% of Year 1 and 2 students tested; 6% of Year 3; and 10% of Year 4). Positive responses were seen as early as Year 3 in students (in their second year of clinical activity and glove use). Positive skin prick test responses to latex were related to a personal history of atopy (p = 0.005), positive prick test responses to common allergens (p < 0.005), latex-attributed immediate pruritus or urticaria (p < 0.05), rhinoconjunctivitis (p < 0.001), and asthma symptoms (p < 0.001). CONCLUSION: Dental school students and faculty are at high risk for latex sensitization. This occurs as early as the second year of glove use. Overall prevalence of skin sensitization was 10% of those tested. Preventive strategies in this group merit further investigation.

Adult↗
PubMed1997

Outcome determinants for isocyanate induced occupational asthma among compensation claimants.

OBJECTIVES: To compare the outcome of occupational asthma (OA) induced by isocyanates in Ontario (where a surveillance programme for exposed workers has been in place for over 15 years), with the outcome of OA induced by other work agents. METHODS: Compensated OA claims during the period 1984-88 in Ontario were retrospectively reviewed in a standardised way. RESULTS: 136/235 compensated claims were attributed to isocyanates. Compared with other causes of OA, those attributed to isocyanates had a shorter latent period before onset (5.9 v 7.9 years, P < 0.05), shorter duration of symptoms before diagnosis (2.0 v 3.0 years, P < 0.05), and less associated atopy (43% v 58%, P < 0.05). Outcome at a mean of 1.9 years after initial assessment was significantly better in those with OA induced by isocyanates; 73% cleared or improved v 56% with other causes of OA (P < 0.05). Ten subjects with OA induced by isocyanates stayed at the same work; none cleared and four had worsened at follow up. A better outcome in OA induced by isocyanates was associated with early diagnosis (P < 0.05), and early removal from isocyanates after the onset of asthma. CONCLUSIONS: The outcome in the group with OA induced by isocyanates is similar to previous follow up studies. However, it is better than the outcome in our comparison group with OA due to other causes, perhaps because of earlier diagnosis in the group with OA induced by isocyanates. This may be attributable to the medical surveillance of workers exposed to isocyanates in Ontario, either directly from the surveillance assessments, or indirectly by increasing awareness of the condition.

Adult↗
PubMed1996

The relationship between latex skin prick test responses and clinical allergic responses.

BACKGROUND: Allergic responses to latex have been reported more frequently in the past 5 years. Although commercial skin prick test solutions are available and can be used in the diagnosis of latex allergy in some countries, the characteristics of patients sensitized to latex relative to their skin test responses have not been reported. OBJECTIVE: The purpose of this study is to relate the clinical characteristics of patients with latex sensitivity to the size of their latex skin prick test response. METHODS: A retrospective review of patients who were attending a hospital-based allergy and asthma clinic and who had positive skin test responses to a commercial latex skin test solution was undertaken. RESULTS: Of 47 patients who had skin test responses to latex, 36 had a mean wheal diameter at least 3 mm greater than the negative control (diluent). Sixty-eight percent were health care workers. There was a positive association between the size of skin test response and severity of latex-induced symptoms (p < 0.001). A history of banana sensitivity was also associated with larger skin test responses (p < 0.05). CONCLUSION: The size of the skin prick test response to latex solution that is commercially available in Canada reflects the severity of latex-induced clinical allergic responses.

Adult↗
PubMed1996

Bronchoprovocation tests in the diagnosis of isocyanate-induced asthma.

Over the past 25 years, investigators have continued to improve on the approach to providing nonirritant exposures for the accurate diagnosis of isocyanate-induced asthma. Although the technology used in testing has become more sophisticated and may be fairly considered the domain of the bioengineer, the chemist, and the industrial hygienist, the requirements of the physician have remained unchanged. The physician must observe the level of exposure closely and monitor the worker's symptoms and lung function. Direct physician involvement in the testing procedure remains critical to the worker's safety and for the accurate diagnosis of isocyanate-induced asthma.

Asthma↗