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Biomedical subjects

L Alfredsson

Publications and source records attributed to L Alfredsson.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effects of drop out in a longitudinal study of musculoskeletal disorders.

OBJECTIVES: The drop out rates in different longitudinal studies of musculoskeletal disorders range between 7% and 57%, and little is known about the characteristics of the subjects who dropped out. The aim was to analyse various consequences of drop out in a longitudinal study of musculoskeletal disorders and occupational risk factors during 1969-97. METHOD: Data about occupational conditions and health in 1969 and in 1993 were analysed. Differences between those who participated throughout (participants) and drop out subjects in these analyses formed the basis for recalculations of earlier reported analyses of associations between occupational conditions and low back pain. In the recalculation the data were weighted to compensate for the differences. RESULTS: More female and male drop out subjects than participants in 1993 had monotonous work, fewer women and more male drop out subjects had heavy lifting in 1969. In 1997, more female and male drop out subjects had had heavy lifting and low stimulation at work in 1993. At both occasions, there were differences between the drop out subjects and participants in occurrence of musculoskeletal disorders. The weighted analyses resulted in changes in risk ratio of 0.1-0.2. CONCLUSIONS: Differences in occupational conditions and health among participants and drop out subjects in a longitudinal study of musculoskeletal disorders and occupational risk factors during 1969-97 did not markedly influence the risk ratios.

Adolescent↗
PubMed2000

To what extent do current and past physical and psychosocial occupational factors explain care-seeking for low back pain in a working population? Results from the Musculoskeletal Intervention Center-Norrtälje Study.

STUDY DESIGN: A population-based case referent study. OBJECTIVES: To determine whether current and past physical and psychosocial occupational factors are associated with care-seeking for low back pain in working men and women. SUMMARY OF BACKGROUND DATA: The importance of physical and psychosocial workloads as causal factors of low back pain has mostly been investigated in special occupational groups and with a cross-sectional design, which makes generalizability and interpretations more difficult. METHODS: The study comprised 2118 working men and women 20 to 59 years old (695 cases, and 1423 referents). Cases were defined as persons seeking care by any caregiver for low back pain. The exposure assessments were made through questionnaires and interviews about current and past physical and psychosocial loads during work and leisure time. RESULTS: In a logistic regression analysis, physical load from forward bending in men (RR = 1.8) and high physical load, in general, in women (RR = 2.0) showed increased relative risks. Psychosocial factors alone seemed to be of less importance in women, but "poor job satisfaction" and "mostly routine work without possibilities of learning" increased the risk in men. Combined current and past exposures further increased the risks. A combination of high physical and psychosocial loads increased the risk substantially, but few were exposed to such loads. Adjustment for lifestyle and other loads outside work did not change the results. CONCLUSION: Current and past physical and psychosocial occupational factors, both separately and combined, seem to be gender-specific, and to have a moderate impact on care-seeking for low back pain in a general working population.

Adult↗
PubMed2000

Physical and psychosocial factors related to low back pain during a 24-year period. A nested case-control analysis.

STUDY DESIGN: A retrospective nested case-control study. OBJECTIVES: To identify occupational factors related to low back pain, and to study how interactions between psychosocial and physical factors, and between work-related and leisure-related factors affect low back pain in women and men. SUMMARY OF BACKGROUND DATA: A cohort of 484 subjects drawn from the general population was examined in 1969 and 1993, with a focus on occupational working conditions and musculoskeletal disorders. METHODS: Information about the physical and psychosocial working conditions and low back pain during the period 1970 to 1993 was collected retrospectively. Odds ratios and confidence intervals were calculated for different potential risk factors. RESULTS: During the 24-year period, 46% of the subjects became patients with low back pain. Among women, heavy physical workload, sedentary work, smoking, and the combination of whole-body vibrations and low influence over work conditions were associated with an excess risk of low back pain. Among men, excess risk for low back pain was seen in heavy physical workload, sedentary work, high perceived load outside work, and the combination of poor social relations and overtime. CONCLUSIONS: Factors at work were seen to be risk indicators for low back pain among both genders. Low influence over work conditions among women and poor social relations at work among men, in combination with other factors, seem to be of high relevance for the occurrence of low back pain.

Adolescent↗
PubMed2000

Risk factors for neck and shoulder disorders: a nested case-control study covering a 24-year period.

BACKGROUND: In 1969 a population-based study was conducted in the Stockholm region. From the 2,579 randomly selected participants (18-65 years of age in 1969), the youngest subset were asked to participate in a reexamination in 1993. Information regarding working conditions, conditions outside work, and neck and shoulder disorders was collected retrospectively for the period 1970-1993. METHODS: Of 783 eligible subjects (42-59 years of age in 1993), 484 responded. Cases of neck/shoulder disorders were defined by past sick leave or medical attention or recent symptoms, depending on available information. For each case (n = 271) two controls were randomly selected, matched by age and gender. Variables regarding both physical and psychosocial conditions were included in the matched analyses. RESULTS: Among women mainly psychosocial factors and among men mainly physical factors were associated with neck/shoulder disorders. The only gender common risk indicator found was repetitive hand work (OR approximately 1.5). Interactive effects were also observed. CONCLUSIONS: The impact on neck/shoulder disorders from separate factors was moderate but combinations of physical and psychosocial factors, as well as of work-related and non-work-related factors, produced relative risks above 2.

Adult↗
PubMed2000

The association between exposure to a rear-end collision and future neck or shoulder pain: a cohort study.

Neck pain is the most frequently reported feature in connection with whiplash injury, but it is also a common complaint in the general population. Therefore it is crucial to include an unexposed comparison group when evaluating the association between neck pain and a previous motor vehicle crash (MVC). To determine whether exposure to a rear-end collision, without or with whiplash injury, is associated with future neck or shoulder pain, a cohort study was conducted. The study population consisted of persons covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were divided into two subgroups, without reported whiplash injury (n = 204) and with reported whiplash injury (n = 232). Two comparison groups, unexposed to MVCs, consisting of 1599 and 2089 persons, were selected with consideration taken to the age and gender distribution in the exposed subgroups. A questionnaire concerning neck or shoulder pain and other subjective health complaints was mailed to all the study subjects at follow-up in 1994, 7 years after the rear-end collision. The relative risk of neck or shoulder pain at follow-up was 1.3 (95% CI 0.8-2.0) in the exposed subjects without whiplash injury compared with the unexposed. The corresponding relative risk in subjects with whiplash injury was 2.7 (95% CI 2.1-3. 5). We conclude that there is no increased risk of future neck or shoulder pain in drivers who did not report whiplash injury in connection with a rear-end collision 7 years earlier. In drivers with reported whiplash injury, the risk of neck or shoulder pain 7 years after the collision was increased nearly three-fold compared with that in unexposed subjects.

Accidents, Traffic↗
PubMed2000

Attack rate, mortality and case fatality for acute myocardial infarction in Sweden during 1987-95. Results from the national AMI register in Sweden.

OBJECTIVE: To assess trends in attack rate, mortality and case-fatality of acute myocardial infarction (AMI) in Sweden. SETTING: All 303 324 Swedes discharged from hospitals, or deceased, with a diagnosis of AMI between 1987 and 1995. DESIGN: Analysis based on the National AMI Register in Sweden. The National AMI Register was assembled by linking the records of the National Hospital Discharge Register and the National Cause of Death Register in Sweden. MAIN OUTCOME MEASURES: Age-standardized attack rate, mortality and case fatality rates for AMI. RESULTS: Between 1987 and 1995, the age-standardized attack rate of AMI declined by 11% for men and 10% for women, whilst mortality from AMI decreased by 14% for both sexes. The decrease was most pronounced for men below the age of 64, with a reduction of 22% in attack rate and nearly 30% in mortality. There was no change over time in the case fatality rates on the date of attack, including also deaths outside hospital, whilst case fatality within 28 days decreased from 49 to 45% amongst men, and 45 to 42% amongst women. This reduction persisted over 1 year of follow-up. CONCLUSIONS: The decrease in attack rate of AMI in Sweden may be attributed both to changes in risk factors amongst the population and to improved medical intervention. The decline in case fatality rates indicates that improved treatment of patients with AMI has contributed to the reduction in mortality. However, the high, and essentially unchanged, proportion of deaths outside hospital stresses the importance of disease prevention.

Adult↗
PubMed1999

Interview versus questionnaire for assessing physical loads in the population-based MUSIC-Norrtälje Study.

BACKGROUND: MUSIC-Norrtälje study is a case-referent study, the aim of which is to find risk and health factors for low back and neck/shoulder disorders. In this part of the study, the interview technique and the self-administered questionnaire used for assessment of physical loads are described and the inter-method reliability of parts of the self-administered questionnaire is estimated. The distribution of exposure levels in a general population is also described. METHODS: The study period was three years from November 1993 to November 1996, and the study subjects totaled 2,480 persons (813 female and 610 male referents, 380 female and 315 male low back cases, 252 female and 106 male neck/shoulder cases). The interview concerned "a typical working day" during the preceding 12 months and comprised assessment of energy expenditure, work postures, and manual materials handling for work and leisure time, including regular sport activities. The self-administered questionnaire comprised 18 questions, each covering 5 different points of time: right now, 5, 10, 15, 20 years ago. The answers to eight of the questions about current conditions were compared to corresponding interview responses. The interview was considered as the "gold standard." RESULTS: Ninety-eight percent of the subjects completed the interview without any great difficulties. According to the interview, the distributions of different exposure levels were generally positively skewed, i.e., the frequency of highly exposed subjects was low in the study base. The correlation between interview and questionnaire responses among the referents was high for time spent "sitting at work" (r = 0.82), "VDU work" (r = 0.87), and work related "motor vehicle driving" (r = 0.80). The correlation was moderate for work-related "hands above shoulder level" (rs = 0.63), and "hands below knee level (trunk flexion)" (rs = 0.66). The correlation was lower for leisure time activities such as "domestic work" (r = 0.55), "time for own activities" (r = 0.39), and "sitting during leisure time" (r = 0.38). Subjects seeking care for low back or neck/shoulder disorder estimated equally correctly or not, as had the referents. However, non-differential misclassification was present in all questions, which will attenuate observed estimates of the relative risk. CONCLUSIONS: Even though interview data are preferable, questionnaire data may be useful for assessing well-defined work tasks and for "sitting at work."

Adult↗
PubMed1999

Physical capacity in relation to present and past physical load at work: a study of 484 men and women aged 41 to 58 years.

BACKGROUND: A negative association has previously been reported between long-lasting physically heavy work and some measures of physical capacity. This relationship was further investigated in a 24-year follow-up study of 484 middle-aged men and women from the general population. METHODS: A questionnaire was administered in 1993 concerning retrospective recall of physical work loads and physical training in the time span between 1970 and 1993. Laboratory tests performed in 1993 included tests of muscle function (maximal isometric strength and dynamic endurance) and aerobic power (submaximal ergometer test). RESULTS: Consistent with the hypothesis, but mainly among the women, associations between long-lasting physically heavy demands and low trunk flexion strength, squatting endurance, and aerobic power were observed. In contrast, low isometric hand grip strength and low weight lifting endurance were seldom seen among those with high physical work loads, indicating a possible maintaining or training effect on the hand/arm/shoulder muscle groups. CONCLUSIONS: Physically heavy work seems to have a different impact on different parts of the musculoskeletal system, an effect that is also different between men and women.

Adult↗
PubMed1999

Risk factors for neck and upper limb disorders: results from 24 years of follow up.

OBJECTIVES: To investigate associations between different potential risk factors, related and not related to work, and disorders of the neck and upper extremities occurring up to 24 years later. METHODS: The study comprised 252 women and 232 men, Swedish citizens, 42-59 years of age and in a broad range of occupations. Information about potential risk factors was available from a former study conducted in 1969. Data on disorders of the neck, shoulder, and hand-wrist disorders were obtained retrospectively for the period 1970-93. RESULTS: Risk factors were found to differ between the sexes. Among women over-time work, high mental workload, and unsatisfactory leisure time were associated with disorders in the neck-shoulder region. Interaction was found between high mental workload and unsatisfactory leisure time. Neck symptoms earlier in life were associated with recurrent disorders. Hand and wrist disorders were associated mainly with physical demands at work. Among men blue collar work and a simultaneous presence of high mental workload and additional domestic workload predicted disorders in the neck-shoulder region. CONCLUSIONS: Factors related and not related to work were associated with disorders of the neck, shoulders, and hands and wrist up to 24 years later in life. These included factors related to working hours which previously have not been noted in this context. Interactions between risk factors both related and not related to work were commonly found.

Adult↗
PubMed1999

Evaluation of questionnaire-based information on previous physical work loads. Stockholm MUSIC 1 Study Group. Musculoskeletal Intervention Center.

OBJECTIVES: The principal aim of the present study was to evaluate questionnaire-based information on past physical work loads (6-year recall). METHODS: Effects of memory difficulties on reproducibility were evaluated for 82 subjects by comparing previously reported results on current work loads (test-retest procedure) with the same items recalled 6 years later. Validity was assessed by comparing self-reports in 1995, regarding work loads in 1989, with worksite measurements performed in 1989. RESULTS: Six-year reproducibility, calculated as weighted kappa coefficients (k(w)), varied between 0.36 and 0.86, with the highest values for proportion of the workday spent sitting and for perceived general exertion and the lowest values for trunk and neck flexion. The six-year reproducibility results were similar to previously reported test-retest results for these items; this finding indicates that memory difficulties was a minor problem. The validity of the questionnaire responses, expressed as rank correlations (r(s)) between the questionnaire responses and workplace measurements, varied between -0.16 and 0.78. The highest values were obtained for the items sitting and repetitive work, and the lowest and "unacceptable" values were for head rotation and neck flexion. Misclassification of exposure did not appear to be differential with regard to musculoskeletal symptom status, as judged by the calculated risk estimates. CONCLUSIONS: The validity of some of these self-administered questionnaire items appears sufficient for a crude assessment of physical work loads in the past in epidemiologic studies of the general population with predominantly low levels of exposure.

Evaluation Studies as Topic↗
PubMed1999

Does a stressful psychosocial work environment mediate the effects of shift work on cardiovascular risk factors?

OBJECTIVES: Associations between shift work, chronic psychosocial work stress, and 2 important cardiovascular risk factors, hypertension and atherogenic lipids were studied. The hypothesis was tested that psychosocial work stress, as defined by the model of effort-reward imbalance, mediates the effects of shift work on cardiovascular risk. METHODS: Altogether 2288 male participants aged 30-55 years in the baseline screening of the Swedish WOLF (work organization, lipids, and fibrinogen) study underwent a clinical examination and answered a standardized questionnaire measuring shiftwork schedules, effort-reward imbalance at work, and health-adverse behavior. RESULTS: In addition to the direct effects of shift work on cardiovascular risk, mediating effects of effort-reward imbalance at work were found. The respective odds ratios (OR) ranged from 2.18 to 2.27 for hypertension and from 1.34 to 1.45 for atherogenic lipids. While the effects remained significant after extensive confounder control concerning hypertension, part of the observed effect on atherogenic lipids was due to behavioral influences. CONCLUSIONS: Despite obvious limitations, the results indicated that a stressful psychosocial work environment acts as a mediator of health-adverse effects of shift work on hypertension and, partly, atherogenic lipids. In terms of occupational health the findings call for a more comprehensive assessment of the health risks associated with shift work.

Adult↗
PubMed1999

Retrospective versus original information on physical and psychosocial exposure at work.

OBJECTIVES: Retrospective exposure assessments are often performed in epidemiologic studies. The presence of an eventual misclassification, both nondifferential and differential, is debated but can rarely be investigated. The aim of this study was to compare self-reported information on the same physical and psychosocial work exposures with 25 years' difference. METHODS: In 1969-1970 a survey of randomly chosen men and women in Stockholm county, concerning, among other things, work exposures, was undertaken. During 1993-1994, 280 subjects participated in a reexamination, regarding psychosocial and physical factors at work and musculoskeletal disorders. The questions were all formulated in the same way as in 1969-1970. RESULTS: When self-reported information on work exposures, collected with a 25-year interval, was compared, acceptable, although not high, agreement was found for 3 out of 4 physical factors and for 4 out of 10 physical environmental factors. Questions measuring psychosocial load had somewhat lower agreement. Current exposure status influenced the memory of past exposures. Study subjects who reported low-back disorders at the reexamination tended to show a better agreement in their assessments of retrospective exposures than those without current symptoms. When relative risks from original and retrospective data were calculated, hardly any influence on the estimates due to that differential misclassification could be found. For persons with and without neck or shoulder symptoms no apparent differences in assessments were found. CONCLUSIONS: Retrospective assessments of exposures at the workplace showed misclassifications to a certain degree. However, the influence of the misclassifications on the risk estimates was limited.

Adult↗
PubMed1998

High effort, low reward, and cardiovascular risk factors in employed Swedish men and women: baseline results from the WOLF Study.

STUDY OBJECTIVE: To examine associations between measures of work stress (that is, the combination of high effort and low reward) and cardiovascular risk factors. DESIGN: Cross sectional first screening of a prospective cohort study. SETTING AND PARTICIPANTS: The study was conducted among 5720 healthy employed men and women living in the greater Stockholm area aged 19-70 years. All analyses were restricted to subjects with complete data (n = 4958). The investigation of associations between indicators of effort-reward imbalance and cardiovascular risk factors was restricted to the age group 30-55 years (n = 3427). MAIN RESULTS: Subjects reporting high effort and low reward at work had a higher prevalence of well known risk factors for coronary heart disease. After adjustment for relevant confounders, associations between a measure of extrinsic effort and reward (the effort-reward ratio) and hypertension (multivariate prevalence odds ratio (POR) 1.62-1.68), increased total cholesterol (upper tertile 220 mg/dl)(POR = 1.24) and the total cholesterol/high density lipoprotein(HDL)-cholesterol ratio (upper tertile 4.61)(POR 1.26-1.30) were found among men. Among women a measure of high intrinsic effort (immersion) was related to increased low density lipoprotein (LDL)-cholesterol (upper tertile 130 mg/dl)(POR 1.37-1.39). Analyses of variance showed increasing mean values of LDL cholesterol with an increasing degree of the effort-reward ratio among men and increased LDL-cholesterol among women with high levels of intrinsic effort (upper tertile of immersion). CONCLUSIONS: Findings lend support to the hypothesis that effort-reward imbalance represents a specific constellation of stressful experience at work related to cardiovascular risk. The relation was not explained by relevant confounders (for example, lack of physical exercise, body weight, cigarette smoking).

Adult↗
PubMed1998

Psychosocial and physical risk factors associated with low back pain: a 24 year follow up among women and men in a broad range of occupations.

OBJECTIVES: To investigate the relation between psychosocial and physical factors at work, as well as conditions during leisure time, and low back pain (LBP) over 24 years. METHODS: The study group consisted of 252 women and 232 men. From a previous study conducted in 1969, data on psychosocial and physical conditions and LBP were available. Data on LBP for 1971-93 were obtained retrospectively in 1993. RESULTS: The prevalence of LBP in 1969 among women and men were 34% and 24%, the cumulative incidences of LBP during 1970-92 were 38% and 43%, and the prevalences in 1993 of having had LBP during the past 12 months were 44% and 39%, respectively. Monotonous work and few or unsatisfactory social contacts outside work were risk factors for LBP in 1969 among women. LBP in 1969 and dissatisfaction with leisure time were risk factors among both sexes for LBP in 1970-92. LBP in 1969 was a risk factor for LBP in 1993 among women and dissatisfaction with leisure time a risk factor among men. Interactions between few or unsatisfactory social contacts outside work, as well as dissatisfaction with leisure time, and several factors related to work were found to increase the risk of LBP among both sexes during the studied periods. CONCLUSIONS: Conditions in leisure time exert a long term influence on LBP. In this study factors related to work had a long term effect only in interaction with leisure time factors.

Adult↗
PubMed1998

Job strain, social support at work, and incidence of myocardial infarction.

OBJECTIVES: The combination of high psychological job demands and low decision latitude (high job strain) has been associated with an increased risk of coronary heart disease. It has been proposed that this may also be the case for low social support at work. The aim of this study was to analyse the relations between these psychosocial factors and incidence of myocardial infarction. METHODS: Associations between psychosocial work characteristics and incidence of myocardial infarction was investigated through a population based case-control study. The study base comprised employed men and women in five Swedish counties during the years 1976-84. Cases of first myocardial infarction were identified from hospital discharge registers and death records from outside hospital, controls were selected through a random sample, and psychosocial work environment was assessed through a job exposure matrix on the basis of the occupation in the 1970 and 1975 censuses. RESULTS: An increased incidence of myocardial infarction was found for men and women in occupations characterised by low decision latitude. For men this increase was seen primarily in combination with high psychological demands (high job strain) and low social support at work. Younger men (30-54 years of age) in occupations with both high job strain and low social support at work had a relative risk of 1.79 (95% confidence interval (95% CI) 1.22 to 2.65) compared with subjects in low strain and high social support jobs after controlling for age, county of residence, and socioeconomic group. CONCLUSIONS: Our results indicate that jobs characterised by low decision latitude, high job strain, or low social support at work may be associated with an increased risk of acute myocardial infarction. If these associations are causal they may be of substantial importance from the point of view of workers' health.

Adult↗