| Reference | Study population | Age (years) | Participation rate | Exposure measured by: | Diagnostic criteria | Adjusted for/matched by | Comparisons | Results, OR (95% CI) | Design | Quality of the study (+, ++, +++); strength/weakness |
| Typpö, 198524 | 919 (416 males & 503 females) radiologically examined by veno-, angio-, uro-, colo-, or cystography, hips and abdomen | 16–86 (mean 57) | – | Questionnaire Present occupation: mental (sic) light moderate heavy | Retrospective radiological hip OA: mild, moderate, severe | – | Heavy manual work vs no controls (mental (sic)/white collar workers) | 1.97 (1.14 to 3.41) | Case-control | + Strength: none. Weakness: participation rate missing. No statistical testing. No adjustment for potential confounders. Data for only part of the study population (n = 505) |
| Jacobsson 198720 | 85 males waiting for hip replacement, 262 males who have had urography | 70–76 | – | Questionnaire Job title classified as heavy/others | Joint-space <3 mm or waiting for THR | Age, height, weight | Heavy labour vs others | 2.2 (1.34 to 4.36) | Case-control | + Strength: none. Weakness: participation rate not described. Results only sparsely described. No statistical analyses carried out |
| Heavy lifting vs others | 2.37 (1.32 to 4.28) | |||||||||
| Vingaard 199125; Olsen 199422 | Cases: 233 males with hip replacement Controls: 302 randomly selected from general population | 50–70 | 89% | Telephone interview Occupational history for the last 20 years Questionnaire Lifting in all occupations | Cases with THR | Age, earlier diseases, sports activities, BMI | Lifted tons | Relative risk | Case-control | +++ Strength: design and material well described. High number of participants. Interviews with specification of different physical activities. Inclusion of subjects having their first myocardial infarction as validation of the exposure measurement. Weakness: use of THR (risk of selection bias). Workload divided in light, medium, and heavy may be a risk of misclassification. Retrospective exposure information (risk of recall bias) |
| Medium exposure | ||||||||||
| <30 years | 1.73 (1.06 to 2.83) | |||||||||
| >30 years | 1.63 (0.98 to 2.73) | |||||||||
| High exposure | ||||||||||
| <30 years | 1.95 (1.23 to 3.09) | |||||||||
| >30 years | 2.74 (1.70 to 4.43) | |||||||||
| Number of lifts>40 kg | ||||||||||
| Medium exposure | ||||||||||
| <30 years | 1.73 (1.06 to 2.82) | |||||||||
| >30 years | 1.60 (0.81 to 3.15) | |||||||||
| High exposure | ||||||||||
| <30 years | 2.35 (1.47 to 3.74) | |||||||||
| >30 years | 3.31 (1.97 to 5.57) | |||||||||
| Vingaard 199127 | High exposure: Males: 116581 (914 OA) Females: 18434 (109 OA) Low exposure: Males: 91057 (320 OA) Females: 24145 (112 OA) | Born 1905–45 | Register-based | Occupation Job title classified by occupational physicians Low/high exposure | Hospitalised in 1981–3 ICD-8 713.00 Hip OA | Age, residence | High vs low exposure | Relative risk | Cohort | ++ Strength: design and material well described. High number of participants. Weakness: Exposure classified by job title and in light, medium, heavy work (risk of misclassification). Case definition: “hospitalised because of hipOA” (risk of selection bias) |
| Born 1905–24 | ||||||||||
| Males | 2.2 (1.6 to 2.8) | |||||||||
| Females | 1.6 (0.9 to 3.1) | |||||||||
| Born 1925–45 | ||||||||||
| Males | 2.0 (1.6 to 2.3) | |||||||||
| Females | 1.1 (0.9 to 1.5) | |||||||||
| Vingaard 199226 | Cases: 140 males disability pension due to hip OA Controls: 298 males from the general population | Born 1915–34 | 73% | Interview Occupational history Job title classified by experienced persons Low/medium/high exposure | Primary diagnosis made by a physician hip OA | Age | High vs low exposure | Relative risk | Case-control | ++ Strength: description of material and design. Weakness: diagnosis (physician certificates, risk of misclassification). Subjects in heavy work may have increased risk of getting disability pension (risk of selection bias). Exposure: “high workload on hips” not especially related to heavy lifting (risk of misclassification) |
| Medium | 4.1 (2.4 to 7.1) | |||||||||
| High | 12.4 (6.7 to 23.0) | |||||||||
| Croft 199216 | Cases: 245 males with hip OA Controls: 294 males without hip OA examined by urography | 60–75 | 68% | Blinded interview Occupational history Specified physical activity | Joint space All <2.5 mm Severe <1.5 mm | Age, sport, BMI | Lifting or moving weights >25.4 kg All JSN <2.5 mm | Case-control | +++ Strength: use of intravenous urograms may avoid selection bias. JSN defined. Results and analysis well described. Weakness: number of severe cases relatively small. Exposure measurement: “lift >25.4 kg”, frequency not further explained (risk of misclassification) | |
| 1–19 years | 0.9 (0.6 to 1.4) | |||||||||
| ⩾20 years | 1.2 (0.7 to 1.9) | |||||||||
| Severe JSN <1.5 mm | ||||||||||
| 1–19 years | 1.2 (0.5 to 2.9) | |||||||||
| ⩾20 years | 2.5 (1.1 to 5.7) | |||||||||
| Roach 199423 | Cases: 99 with primary hip OA Controls: 233 with no radiographic hip OA examined by intravenous urography | Average: 68 | 77% (total 48%, chosen from a population of 693) | Questionnaire Occupational history Classified in light, intermediate and heavy work | Kellgren & Lawrence grade 3–4 (joint space <1.5 mm) | Obesity, age, sports activities, cancer | Intermediate vs light work | 1.9 (1.0 to 3.8) | Case-control | ++ Strength: JSN defined. Adjustment for obesity, age, sport. Weakness: high exclusion rate. Retrospective exposure measurement (risk of recall bias). Exposure divided in light or heavy work (risk of misclassification) |
| Heavy vs light work | 2.4 (1.3 to 4.3) | |||||||||
| Vingaard 199728 | Cases: 273 females with THR in 4 areas of Sweden Controls: 273 females random sample from same areas | 50–70 | 90% | Interview Occupational history Specified physical activity | THR | Age, BMI, sports activity, number of children, hormone therapy | Heavy lifts vs light | Relative risk | Case-control | ++ Strength: high participation rate. Occupational history by interview with specification of different physical activities. Adjustment for age, BMI, sports. Weakness: retrospective exposure data (risk of misclassification). Only number of heavy lifts (not further defined) reported |
| Medium | 1.1 (0.7 to 1.7) | |||||||||
| High | 1.5 (0.9 to 2.5) | |||||||||
| Coggon 199815 | Cases: 210 males 401 females waiting for surgery in three English districts Controls: 210 males, 401 females (random sample from general practices in the same area) | 45–91, mean: 70 | 68% | Interview Occupation held for >1 year from school age Specified physical activity | Cases waiting for surgery | BMI, hip injury, Heberden’s nodes. Matched by age and gender | Heavy lifts at least 10 years 10 times/week vs no lifting | Case-control | +++ Strength: high number of participants. Well described study. Exposure collected by interviews with specification of different physical activities. Results adjusted. Weakness: participation rate 84% of cases, 58% of controls. Cases from a waiting list for THR (risk of selection bias). Retrospective exposure measurement (risk of recall bias). Few women in high exposure group | |
| Males | ||||||||||
| Lift >10 kg | 2.3 (1.2 to 4.2) | |||||||||
| Lift >25 kg | 2.7 (1.4 to 5.1) | |||||||||
| Lift >50 kg 1 | 3.2 (1.6 to 6.5) | |||||||||
| Females | No significant differences | |||||||||
| Cvitetic 199917 | 590 (292 males 298 females) random sample from Zagreb city records 1981–3 | >45, mean: 63 | – | Questionnaire Occupation divided in 4 categories: mostly sedentary; mostly standing; no sitting; high physical strain | Clinical and radiological hip OA in right hip Kellgren & Lawrence grade 2–4 | – | Standing or lifting vs >80% sitting or standing | Cohort | + Strength: high number of participants. Weakness: participation rate not described. Results not controlled for confounders. Heavy lifting defined as lifts >5 kg (risk of misclassification) | |
| Males | 1.5 (0.6 to 3.21) | |||||||||
| Females | 1.45 (0.49 to 3.58) | |||||||||
| Standing, walking, light work | ||||||||||
| Males | 1.16 (0.58 to 2.3) | |||||||||
| Females | 1.19 (0.65 to 2.32) | |||||||||
| Standing, walking, often heavy lifting >5 kg | ||||||||||
| Males | 1.15 (0.52 to 2.52) | |||||||||
| Females | 1.34 (0.52 to 3.04) | |||||||||
| Yoshimura 200029 | Cases: 103 females 11 males waiting for hip replacement in 2 districts in Japan Controls: 114 from the local population | >45, mean: 64 | 91% | Questionnaire Occupation since leaving school; physical activity in their first and main job | Waiting for hip replacement | Age, gender, residence matched | Lift vs no lift | Case-control | + Strength: same design as Coggon et al and Lau et al. Weakness: few participants, especially among males. Few women reported heavy lifting. Case definition (THR, risk of selection bias). Retrospective exposure data (risk of recall bias) | |
| First job | ||||||||||
| Lifting >10 kg | 1.2 (0.6 to 2.4) | |||||||||
| Lifting >25 kg | 3.5 (1.3 to 9.7) | |||||||||
| Lifting >50 kg | – | |||||||||
| Main job | ||||||||||
| Lifting >10 kg | 1.2 (0.6 to 2.1) | |||||||||
| Lifting >25 kg | 1.5 (0.7 to 3.0) | |||||||||
| Lifting >50 kg | 4.1 (1.1 to 15.2) | |||||||||
| Lau 200021 | Cases: 30 males, 108 females hospitalised in Hong Kong with hip OA Controls: 90 males, 324 females from general practice over a 3-year period. | – | – | Interview Physical activity in the job in which they had work for the longest period before symptom | THR (71%) Waiting for surgery (10%) Radiographic grade 3–4 OA (19%) | Matched by gender and age | Lift of 10 kg vs no lift | Case-control | ++ Strength: same design as Coggon et al and Yoshimura et al. Weakness: only very few Chinese subjects with THR, especially in men. Case definition (THR, risk of selection bias). Retrospective exposure data (risk of recall bias) | |
| 1–10 times per week | ||||||||||
| Males | 1.9 (0.6 to 6.6) | |||||||||
| Females | 0.7 (0.4 to 1.5) | |||||||||
| >10 times per week | ||||||||||
| Males | 5.3 (1.8 to 15.8) | |||||||||
| Females | 0.7 (0.4 to 1.5) | |||||||||
| Lift of 50 kg vs no lift | ||||||||||
| 1–10 times per week | ||||||||||
| Males | 8.5 (1.6 to 45.3) | |||||||||
| Females | 2.9 (0.9 to 4.6) | |||||||||
| >10 times per week | ||||||||||
| Males | 9.6 (2.2 to 42.2) | |||||||||
| Females | 2.9 (1.5 to 5.6) | |||||||||
| Flugsrud 200218 | 278 males; 391 females from the Norwegian Arthroplastry Register 1989–98 24884 males, 24874 females from the Cardiovascular Screening Register 1981–3 | Mean: 55 | 92% | Questionnaire Graduated physical activity “during the last year” in sedentary; walking; walking and lifting; heavy manual labour Follow-up length 9 years | THR | Age, height, marital status, smoking | Heavy lifting vs sedentary work | Relative risk | Cohort | +++ Strength: large number of participants, high participation rate, prospective design. Weakness: Case definition (THR, risk of selection bias). Exposure measurement “physical activity during the 12 months” 1981–3 (risk of misclassification) |
| Moderate | ||||||||||
| Males | 1.5 (1.0 to 2.2) | |||||||||
| Females | 1.1 (0.8 to 1.6) | |||||||||
| Intermediate | ||||||||||
| Males | 1.7 (1.1 to 2.4) | |||||||||
| Females | 1.4 (0.9 to 2.0) | |||||||||
| Intensive | ||||||||||
| Males | 2.1 (1.5 to 3.0) | |||||||||
| Females | 2.1 (1.3 to 3.3) | |||||||||
| Jacobsen 200419 | 1533 males 2618 females from Copenhagen City Heart Study Hip OA cases 105 males 167 females | 23–93 mean: 63–65 | – 41% of the initial cohort selected for radiography | Questionnaire Physical activity since leaving school Mostly seated, standing/ walking, no lifting Lifting 1 ton Lifting 1–2 tons Lifting 2–5 tons Lifting >5 tons | Standing radiographs Case definition: JSN <2 mm | Age, BMI | Mostly seated, standing, walking, no lifting Lifting 1 tons Lifting 1–2 tons Lifting 2–5 tons Lifting >5 tons | No significant relations between type and duration of occupations (sedentary or involving repeated daily lifting OR 0.7–1.0 | Cohort | ++ Strength: high number of participants, prospective design, well described exposure measurements. Weakness: data and statistical analysis are not shown |
THR, total hip replacement; SHR, standardised hospitalisation ratio; BMI, body mass index (weight/height2); OA, osteoarthritis.
+ Poor quality score 1–5; ++ medium quality score 6–10; +++ high quality score >10.