Vision rehabilitation: recipients' perceived efficacy of rehabilitation.

OBJECTIVE/PURPOSE: This survey was conducted to determine the effect on activities of daily living of persons who report that they have received vision rehabilitation. DESIGN/METHODOLOGY: This study used a clinical sample to gather information from 417 patients. Of the 417, 105 reported receiving vision rehabilitation. The efficacy of rehabilitation was assessed by asking 20 questions about their activities of daily living prior to and after their rehabilitation. A retrospective pretest (post-then-pre) design was used. Paired t tests were conducted to evaluate the effect of rehabilitation. RESULTS: A significant difference was found for 13 of 20 questions. Difficulty reading ordinary prints in newspapers showed a large effect size (p=0.0005). Difficulty reading the small print in a telephone book showed a large effect size (p=0.0005). Difficulty doing work or hobbies that require one to see up close showed a moderate effect size (p=0.0005). Difficulty finding something on a crowded shelf showed a moderate effect size (p=0.0005). Difficulty figuring out whether bills received are accurate showed a moderate effect size (p=0.0005). Difficulty shaving, styling one's hair, or putting on makeup showed a small effect size (p=0.016). Difficulties seeing and enjoying programs on television showed a moderate effect size (p=0.0005). CONCLUSION: Patients with low vision who report having received vision rehabilitation show significant improvements in activities of daily living or specific types of functioning after rehabilitation. Improvement in both near and distance vision activities and in social activities indicates daily functioning was improved and that barriers to activities of daily living were removed.

Nonfatal work-related inhalations: surveillance data from hospital emergency departments, 1995-1996.

BACKGROUND: Data from a stratified sample of hospital emergency rooms in the USA were used to describe nonfatal work-related inhalation injuries and illnesses during July 1995 to July 1996. METHODS: Information was abstracted from emergency room records by the Consumer Product Safety Commission (CPSC) as part of the National Electronic Injury Surveillance System (NEISS) for all work-related injuries and illnesses regardless of product involvement. RESULTS: There were an estimated 44,423 occupational inhalation cases nationwide, with an annual rate of 3.6 cases/10(4) workers/year. The rate for men (4.4 cases/10(4)) was greater than that observed for women (2.6 cases/10(4)), and the rates tended to decline with increasing age. An estimated 4.6% of the cases were hospitalized for further treatment. The highest rate by industry was 16.4 cases/10(4) for public administration (which included fire and police departments). Among non-firefighters, there were an estimated 6,470 cases nationwide in which respiratory symptoms or conditions were noted, which yielded an annual rate of 0.5 cases/10(4) (95% CI 0.3, 0.7). Chlorine compounds were a common agent for the cases with adverse respiratory outcomes. CONCLUSIONS: The NEISS data provide an efficient method to learn about the national frequency of work-related inhalation injuries and illnesses. The National Institute for Occupational Safety and Health (NIOSH) is exploring two ways to use these data: first, to routinely review the reports to conduct surveillance for work-related inhalation cases; and second, to consider working with CPSC to conduct follow-back interviews of selected cases in order to learn more about the circumstances of the exposure, prior training of the case, and outcome of the exposure. Am. J. Ind. Med. 38:140-148, 2000. Published 2000 Wiley-Liss, Inc.

Recent trends of age-specific pneumoconiosis mortality rates in the United States, 1985-1996: coal workers' pneumoconiosis, asbestosis, and silicosis.

The authors examined the temporal trends of age-specific pneumoconiosis mortality from coal worker's pneumoconiosis (CWP), asbestosis, and silicosis in the United States in 1985-1996. Mortality data were derived from the National Center for Health Statistics multiple causes of death files for the period. Age-specific mortality rates were computed for three age groups (15-44, 45-64, and > or = 65 years) among decedents with mention of CWP, asbestosis, or silicosis. Linear regression analysis was performed to examine the annual changes in age-specific mortality rates, by age group, with each specific condition. The CWP mortality rates declined significantly (p = 0.0001) in the groups 45 years old and older, but not in the age group 15-44. Asbestosis mortality rates declined significantly (p = 0.005) for the age group 45-64, while increasing (p = 0.0001) for those aged 65 years and older. However, in the younger age group 15-44, the rates showed no significant trend. Silicosis mortality rates declined significantly (p = 0.0001) for all groups. The continued occurrence of deaths from CWP, asbestosis, and silicosis among young adults may be the result of high levels of exposure to occupational risks. These results suggest that pneumoconiosis surveillance may help to evaluate the temporal pneumoconiosis mortality patterns in the United States.

Surveillance of respirable crystalline silica dust using OSHA compliance data (1979-1995).

BACKGROUND: The objective of this work was to estimate the percentage of workers by industry that are exposed to defined concentrations of respirable crystalline silica dust. METHODS: An algorithm was used to estimate the percentage of total workers exposed to crystalline silica in 1993 at concentrations of at least 1, 2, 5, and 10 times the National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL) of 0.05 mg/m3. Respirable crystalline silica air sampling data from regulatory compliance inspections performed by the Occupational Safety and Health Administration (OSHA), for the years 1979-1995, and recorded in the Integrated Management Information System (IMIS) were used to estimate exposures. Therefore, this work does not include industries such as mining and agriculture that are not covered by OSHA. The estimates are stratified by Standard Industrial Classification (SIC) codes. RESULTS: This work found that some of the highest respirable crystalline silica dust concentrations occurred in construction (masonry, heavy construction, and painting), iron and steel foundries (casting), and in metal services (sandblasting, grinding, or buffing of metal parts). It was found that 1.8% (13,800 workers) of the workers in SIC 174--Masonry, Stonework, Tile Setting, and Plastering--were exposed to at least 10 times the NIOSH REL. For SIC 162--Heavy Construction, Except Highway and Street Construction--this number is 1.3% (6,300 workers). SIC 172--Painting and Paper Hanging--which includes construction workers involved in sandblasting was found to have 1.9% (3,000 workers) exposed to at least 10 times the NIOSH REL. The industry that was found to have the highest percentage of workers (6%) exposed to at least the NIOSH REL was the cut stone and stone products industry. CONCLUSION: Not enough is being done to control exposure to respirable crystalline silica. Engineering controls should be instituted in the industries indicated by this work.

Exposure and mineralogical correlates of pulmonary fibrosis in chrysotile asbestos workers.

OBJECTIVES: The relation between lifetime cumulative exposure to asbestos, pathological grade of pulmonary fibrosis, and lung burden of asbestos at death, was explored in a necropsy population of former workers in a chrysotile asbestos textile plant in South Carolina. METHODS: Estimates of cumulative, mean, and peak exposures to asbestos were available for 54 workers. Necropsy records and lung tissue samples were obtained from hospital files. Matched control cases were selected from consecutive necropsies performed at the same hospitals. The extent and severity of pulmonary fibrosis was graded on tissue sections. Mineral fibres in lung tissue were characterised by transmission electron microscopy combined with x ray spectroscopy. RESULTS: A significant positive correlation (r = 0.67, P < 0.0001) was found between lifetime cumulative exposure to asbestos and total lung burden of asbestos fibres. This relation was also found for the individual types of asbestos associated with the exposure: chrysotile and tremolite. Pulmonary fibrosis was correlated with both cumulative exposure to asbestos (r = 0.60, P < 0.01) and the concentration of asbestos fibres in the lung (r = 0.62, P < 0.0001). The concentration of tremolite fibres in the lung provided a better estimate of lung fibrosis than did the concentration of chrysotile. Asbestosis was usually present in asbestos textile workers with more than 20 fibre-years cumulative exposure. The lengths and aspect ratios of chrysotile asbestos, but not amphibole asbestos, were greater in the lungs of asbestos fibre workers than in the control population. Textile workers with lung cancer had significantly greater cumulative exposures and fibrosis scores than workers without lung cancer. CONCLUSIONS: Both cumulative exposure to asbestos and lung fibre burden are strongly correlated with severity of asbestosis. The data also support the hypothesis that the high prevalence of asbestosis and lung cancer in this population resulted from exposure to long fibres of chrysotile asbestos in the workplace.

Approaches for assessing the efficacy of occupational health and safety standards.

The regulation of hazards is one of the most dramatic forms of intervention in occupational safety and health (OSH). Despite their high degree of potential social and economic impact, relatively little research has been conducted to specifically evaluate the effectiveness of OSH standards with regard to preventing occupational diseases and injuries. This paper reviews the basic scientific approaches that may be used to evaluate the efficacy of OSH standards. These approaches encompass the following research areas: (1) exposure surveillance, (2) disease surveillance, and (3) prospective studies following the introduction of the standard. Research on asbestos and asbestosis, respirable crystalline silica (quartz) and silicosis, and respirable coal mine dust and coal workers' pneumoconiosis (CWP) are used to illustrate these approaches and the type of information that is currently available. The examples (quartz, coal dust, asbestos) reveal substantial limitations in the types of information currently available for evaluating the efficacy of these OSH standards. Ideally, plans for evaluating the efficacy of OSH standards should be developed for existing and future standards. These plans should include programs for the surveillance of exposures and adverse health effects and, when possible, for prospective studies designed to evaluate how the risk of disease (or injury) is modified by the introduction of the standard.

Surveillance data on US coal miners' pneumoconiosis, 1970 to 1986.

OBJECTIVES: Statistics on prevalence of pneumoconiosis among working underground coal miners from data collected as part of a large national radiographic surveillance program between 1970 and 1986 are presented. The main intent was to examine the time-related trend in prevalence over this period, which coincides with historically low dust levels mandated by federal act. METHODS: Tenure-specific prevalence rates and summary statistics derived from them for four consecutive time intervals within the 16-year period were calculated and compared. RESULTS: The results indicate a reduction in pneumoconiosis over the life of the program. This trend is similar to that seen in epidemiologic studies undertaken concurrently. CONCLUSIONS: Although low participation in the surveillance program and other problems complicate the findings, it appears that reductions in dust exposure mandated by federal act in 1969 have led to lower prevalence of pneumoconiosis among underground coal miners.

The Western Washington Myocardial Infarction Registry and Emergency Department Tissue Plasminogen Activator Treatment Trial.

This study comprised a registry and an emergency department treatment trial using recombinant tissue plasminogen activator. During 1 year, 1,028 patients with documented acute myocardial infarction (AMI) were evaluated for eligibility for thrombolytic therapy. Of these, 221 patients (22%) were eligible for thrombolytic therapy under currently accepted criteria, 175 (79%) of them were correctly identified by emergency department physicians for thrombolytic therapy, and 160 were enrolled in the trial. Only 3 patients (2%) enrolled by emergency department physicians did not subsequently evolve documented AMI. In all, 807 patients (78%) were ineligible for thrombolytic therapy: 335 (33%) because of greater than or equal to 1 contraindications, 364 (36%) because of nondiagnostic electrocardiograms on presentation, and 105 (10%) because of age greater than 75 years, or greater than 6 hours of chest pain at presentation, or both. Mortality in treated patients at 14 days was 5.6%, and survival at 1 year was 92%. The mean time from hospital arrival to thrombolytic treatment was 55 +/- 27 minutes. Initial management of AMI with recombinant tissue plasminogen activator in the emergency department provided rapid and safe treatment comparable to that reported in trials that started treatment in the coronary care unit. The proportions of eligible patients could be increased from 1 in 5 to 1 in 3, if patients currently excluded only because of age greater than 75 years or because of greater than 6 hours of chest pain were offered treatment.

Echocardiographic evaluation of segmental wall motion early and late after thrombolytic therapy in acute myocardial infarction: the Western Washington Tissue Plasminogen Activator Emergency Room Trial.

In 92 acute myocardial infarction (AMI) patients treated with tissue plasminogen activator 2.3 +/- 1.2 hours after the onset of chest pain, echocardiography was performed at 11 +/- 14 hours (early) and, in 49 patients, again at 13 +/- 7 weeks (late). Infarct location and the left ventricular wall motion score index--the average score (normal = 1, hypokinetic = 2, akinetic = 3, dyskinetic = 4) for 20 segments--were determined by 2 observers unaware of clinical, angiographic or electrocardiographic data. Concordance between noninvasive infarct location by electrocardiography or echocardiography and infarct-related artery at angiography 4 +/- 2 days later (n = 85) was 76 and 81%, respectively. The early wall motion score index was worse for anterior (1.8 +/- 0.4) versus inferior (1.3 +/- 0.2, p less than 0.0001) or posterior-lateral (1.6 +/- 0.2, p = 0.0003) infarcts. Overall, the wall motion score index improved from early to late echocardiography (n = 49, 1.5 +/- 0.3 to 1.3 +/- 0.3, p = 0.0008). However, improvement was confined to those with time to treatment less than or equal to 2 hours (n = 22, 1.4 +/- 0.3 to 1.2 +/- 0.2, p less than 0.0001), and evidence of reperfusion at angiography (n = 38, 1.5 +/- 0.3 to 1.2 +/- 0.3, p less than 0.0001). The decrease in the wall motion score index was related to a decrease in the number of adjacent involved segments (5.5 +/- 3.0 to 3.7 +/- 3.9/patient, p = 0.0006). Thus, echocardiography early after AMI identifies infarct location. Improvement in regional wall motion is seen after early treatment with intravenous tissue plasminogen activator.

Early versus late hospital arrival for acute myocardial infarction in the western Washington thrombolytic therapy trials.

In the 3 Western Washington thrombolytic therapy trials, 54.9% of patients with acute myocardial infarction arrived at the hospital within 2 hours of symptom onset. These early arrivers were younger and more likely to be hypotensive and in cardiogenic shock than were patients arriving later. There were decreases in the time from symptom onset to hospital arrival (p = 0.0002) and in the time from hospital arrival to institution of thrombolytic therapy (p less than 0.0001) in the 8 hospitals that participated in both the Western Washington intravenous streptokinase and tissue plasminogen activator trials from 1983 to 1988. For those patients receiving thrombolysis, early arrival was associated with increased survival (p = 0.031) after adjustment by Cox regression analysis for important clinical predictors of long-term survival. These covariates included pulmonary edema, anterior wall acute myocardial infarction, hypotension and absence of chest pain at hospital arrival. Reductions in barriers to timely administration of thrombolytic therapy can be achieved and can result in improved survival.

Prevalence of silicosis at death in underground coal miners.

This study was initiated by the National Institute for Occupational Safety and Health (NIOSH) and the Bureau of Mines (BOM) to determine the prevalence and pathological features of silicosis in coal miners. The population base was 3,365 autopsied underground miners whose records were submitted to the U.S. National Coal Workers' Autopsy Study between 1971 and 1980. This program is voluntary and covers an estimated 10% of all coal workers who die. The mean age at death of the population was 62 years, of whom 75% were current or ex-smokers at the time of death. The average work tenure was 26 years. Lung sections from all cases were reviewed and the type and severity of pneumoconiosis documented. These findings were correlated with years of mining, job history, and geographic location of mine. Classical silicotic nodules were found in 12.5% of the population. There was a significant relationship between length of underground mining and prevalence and severity of silicosis consistent with a dose-response effect. The study also showed that job category and geographic location of the mine were important determinants of silicosis prevalence and that silicosis was strongly associated with higher categories of coal workers' pneumoconiosis.

The morbidity and mortality of vermiculite miners and millers exposed to tremolite-actinolite: Part III. Radiographic findings.

A study was conducted to estimate the exposure-response relationship for tremolite-actinolite fiber exposure and radiographic findings among 184 men employed at a Montana vermiculite mine and mill. Workers were included if they had been employed during 1975-1982 and had achieved at least 5 years tenure at the Montana site. Past fiber exposure was associated with an increased prevalence of parenchymal and pleural radiographic abnormalities. Smoking was not significantly related to the prevalence of small opacities. However, the number of workers who had never smoked was small, and this prevented measurement of the smoking effect. Under control for smoking and age, the prevalence of small opacities was significantly greater for vermiculite workers with greater than 100 fiber/cc-years exposure than for comparison groups (cement workers, blue collar workers, and coal miners) who had no known occupational fiber exposure. A logistic model predicted an increase of 1.3% in the odds ratio for small opacities at an additional exposure of 5 fiber-years.

Use of data from X-ray screening program for coal workers to evaluate effectiveness of 2 mg/m3 coal dust standard.

The National Institute for Occupational Safety and Health administers the X-ray Screening Program for underground coal miners, a program mandated by the Federal Mine Health and Safety Act of 1969. The screening file, with over 200,000 x-ray films, affords an excellent source for the study of prevalence and progression of Coal Workers' Pneumoconiosis. Two epidemiological analyses have recently been completed. One, a prevalence study of miners with 10 or fewer years of mining tenure, converted screening readings to median epidemiological readings. Converted prevalences were 0.44% for the group with 0 to 1 year tenure and 0.79% for the group with 1 to 9 years tenure. This result is similar to prevalence observed in a study of nonexposed blue collar workers. A second analysis reread x-ray films of a subgroup of 1,834 repeat miners with roughly 9 years exposure only under mandated dust standards. Net progression from category 0/0 was observed to be 1.2%. This value is consistent with 1.9%, based on an average dust exposure, predicted by British research. Results must be interpreted in light of several possible sources of bias.

Lung carcinoma by histologic type in coal miners.

Histologic types of lung carcinoma were studied in 171 coal miners in the National Coal Workers' Autopsy Study. These miners had an average underground mining tenure of 29 +/- 14 years and an average smoking history of 31 +/- 23 pack-years. The proportion of carcinomas by cell type were: squamous cell carcinoma, 30%; adenocarcinoma, 27%; small-cell undifferentiated carcinoma, 26%; large-cell undifferentiated carcinoma, 9%; and other carcinomas, 8%. More tumors were observed in the right lung and in the upper lobes of both lungs than in the left lung and in the lower lobes of both lungs, respectively. The majority of the tumors were centered on cartilaginous airways (81%) as compared with the peripheral regions of the lung (19%). Squamous cell carcinomas predominated in the older miners and in larger airways. Adenocarcinomas were more common in the peripheral lung. No significant interaction was demonstrated between cell type and years of underground mining. The data indicate that lung carcinoma in coal miners differs little in its pathologic features from men in the general population who smoke cigarettes. No effect of coal mine dust exposure on lung carcinoma histogenesis was demonstrated.

Silicosis in silica flour workers.

In July 1979, the health of 86 current and ex-workers at 2 silica mining and milling operations in southern Illinois was examined using a respiratory questionnaire, spirometry, and chest radiographs. None of 25 current workers with less than 1 yr of exposure to silica dust had radiographic evidence of silicosis. For 61 current workers and ex-workers with 1 or more yr of exposure, chest radiographs showed 16 (26%) with simple silicosis and 7 (11%) with progressive massive fibrosis. Of these 23, 8 with simple silicosis and 3 with progressive massive fibrosis began work after the first Mine Safety and Health Administration inspection in 1973. These data and a review of federal dust inspection results between 1973 and 1979 showed that these cases of silicosis could have been prevented by effecting compliance with the existing dust standard.

Survival and handicap of infants with spina bifida.

A follow-up study was carried out on 213 infants born with spina bifida cystica (including encephalocele and occipital meningocele) from 1965 to 1972 to women resident in Oxfordshire and the western part of Berkshire. The 5-year survival rate was 36% (39/107) for those with open lesions, 60% (30/50) for those with closed ones, and 18% (10/56) for those with lesions which could not be classified (not known) but which were probably nearly all open. The extent of handicap among these survivors was assessed by means of criteria described by Lorber; among those with open lesions (including 'not known') 84% (41/49) were severely handicapped, 10% (4/49) were moderately handicapped, and only 6% (3/49) had no handicap; among those with closed lesions, 37% (11/30) were severely handicapped, 33% (10/30) were moderately handicapped, and the remaining 30% (9/30) were not handicapped. Closed head lesions (encephalocele or occipital meningocele) were more often associated with severe handicap (6/8; 75%) than were closed spinal lesions (5/22; 23%). The children with open lesions who survived for at least 5 years spent, on average, at least 6 months in hospital during the first 5 years of their life and had, on average, at least 6 major surgical operations. In comparison, those with closed lesions spent one-third less time in hospital, and had fewer than half as many operations. During the period of the study a selective treatment policy was adopted typical of that commonly practised now, and all the infants were born before antenatal screening had been introduced. Our results therefore may be helpful in assessing the benefits to be expected from antenatal screening for open spina bifida.