Table 1.
Summary of socioeconomic differences in the incidence, prevalence and outcomes of knee OA.
| SES Measure | Study Author and Year | Data Source | Country | Health Outcome | Selected Results Point estimate (95% CI) |
|---|---|---|---|---|---|
| Education | Murphy et al 20165 | Joco OA | US | IR per 100 person-years for knee symptoms, rKOA, severe rKOA, sxKOA, severe sxOA |
Severe rKOA: <high school vs ≥ high school IR=2.8 (2.3–3.4) |
| Hannan et al 199241 | NHANES-I | US | Prevalence rKOA, knee pain |
rKOA: ≤ 8 years vs ≥ 13 years aOR = 1.53 (1.09–2.23) knee pain: ≤ 8 years vs ≥ 13 years aOR = 1.34 (1.09–1.65) |
|
| Callahan et al 201044 | JoCo OA | US | Prevalence of rKOA, bilateral rKOA,sxKOA, bilateral sxKOA |
sxKOA: <12 years vs. ≥ 12 years aOR = 1.86 (1.20 – 2.87) |
|
| Callahan et al 201145 | JoCo OA | US | Prevalence of rKOA, bilateral rKOA, sxKOA, bilateral sxKOA |
rKOA: <12 years vs. ≥ 12 years aOR = 1.44 (1.20–1.73) sxKOA: <12 years vs. ≥ 12 years aOR = 1.66 (1.34–2.06) |
|
| Grotle et al 200842 | MSK pain survey | Norway | Prevalence self-reported KOA |
self-reported KOA: ≤ 9 years vs. > 12 years aOR =2.25 (1.43–3.57) 9–12 years vs. >12 years aOR = 2.32 (1.54–3.50) |
|
| Jorgensen et al 201143 | Danish National register | Denmark | Prevalence knee OA by ICD-8 code | Highest education vs. vocational/basic school Knee OA among women: RR = 0.62 (0.60–0.65) Knee OA among men: RR = 0.50 (0.48– 0.53) |
|
| Cleveland et al 201346 | JoCo OA | US | WOMAC function, pain, stiffness total in rKOA and sxKOA |
rKOA and WOMAC function: <12 years vs. ≥ 12 years aβ = 2.83 (0.38,5.28) |
|
| Feldman et al 201591 | AViKA TKR cohort | US | WOMAC pain and function, pain catastrophizing |
% with high pain (WOMAC >55) among people with knee rOA, adjusted: Less than college: 32.6% (21.3%, 43.9%) Some college: 29.9% (19.9%, 40.0%) College graduate: 21.1% (15.3%, 26.9%) |
|
| Kiadaliri et al 201748 | Malmӧ OA Study | Sweden | Knee pain, rKOA, KOOS pain, other symptoms, ADL, QOL, Swedish EQ-5D-3L | Education <9 years vs. 10–12 years vs. college Frequent knee pain: aRII = 0.71 (0.61–0.84) rKOA: aRII=0.53 (0.29–0.98) KOOS pain: aRII=0.61 (0.42–0.90) KOOS ADL: aRII=0.52 (0.36–0.77) |
|
| Hawker et al 200247 | Mail survey Ontario | Canada | Need for knee or hip arthroplasty | Likelihood for potential need for arthroplasty: <high school vs. ≥ high school aOR = 1.57 (1.17–2.11) | |
| Occupation | Callahan et al 201145 | JoCo OA | US | Prevalence of rKOA, bilateral rKOA, sxKOA, bilateral sxKOA | For all prevalence knee OA outcomes and non-managerial vs. managerial occupations: no significant independent association beyond educational attainment and community poverty |
| Cleveland et al 201346 | JoCo OA | US | WOMAC function, pain, stiffness total in rKOA and sxKOA | rKOA and WOMAC pain: managerial vs. non-managerial occupation aβ = 0.78 (0.08,1.48) | |
| Kiadaliri et al 201748 | Malmӧ OA Study | Sweden | Knee pain, rKOA, KOOS pain,other symptoms, ADL, QOL, Swedish EQ-5D-3L | Occupation: unskilled manual, skilled manual, low-level non-manual, intermediate non-manual, high-level non-manual Frequent knee pain: aRII = 0.70 (0.60–0.82) rKOA: aRII = 0.55 (0.31–0.98) KOOS pain: aRII=0.57 (0.39–0.83) KOOS ADL: aRII=0.49 (0.34–0.72) |
|
| Income | Murphy et al 20165 | Joco OA | US | IR per 100 person-years for knee symptoms, rKOA, severe rKOA, sxKOA, severe sxOA | Knee symptoms: <$15,000 vs ≥$35,000 IR = 7.4 (6.3–8.7) |
| Jorgensen et al 201143 | Danish National register | Denmark | Prevalence Knee OA by ICD-8 code | ≥150% vs. 75–124% average household income Knee OA among women: RR = 0.80 (0.77–0.83) Knee OA among men: RR = 0.77 (0.74–0.80) |
|
| Reichmann et al 201151 | NHANES-III OAI | US | Health Status – % poor/fair |
Among people with rKOA: NHANES-III: <$20,000 = 46.5% (36.8%, 56.10%) $50,000+ = 8.3% (1.9%, 14.8%) OAI: <$20,000 = 11.3% (7.5%, 15.10%) $50,000+ = 1.0% (0.0%, 2.3%) |
|
| Hawker et al 200247 | Mail survey Ontario | Canada | Need for knee or hip arthroplasty |
Likelihood of potential need for arthroplasty: ≤$20,000 vs > $40,000 aOR 1.83 (1.24–2.70) |
|
| Community Poverty | Callahan et al 201145 | JoCo OA | US | Prevalence of rKOA, bilateral rKOA, sxKOA, bilateral sxKOA |
rKOA: high poverty vs. low poverty aOR = 1.83 (1.43–2.36) sxKOA: high poverty vs low poverty aOR = 1.36 (1.00–1.83) |
| Cleveland et al 201346 | JoCo OA | US | WOMAC function, pain, stiffness total in rKOA and sxKOA |
sxKOA and WOMAC pain: high poverty vs. low poverty aβ = 1.35 (0,06, 2.64) |
|
| Area-level SES | Feldman et al 201591 | AViKA TKR cohort | US | WOMAC pain and function, pain catastrophizing) |
% with high pain (WOMAC >55) among people with knee rOA, adjusted Low area SES: 34.2% (25.3%, 43.1%) Mid area SES: 26.6% (17.0%, 34.2%) High area SES: 18.6% (11.8%, 25.5%) |
| Social Class | Peters et al 200550 | SASH | UK | New Zealand Score for knee pain and disability |
Knee pain and disability: lowest social class vs highest, adjusted mean difference = 8.3 (−1.8–18.3) |
| Deprivation | Reyes et al 201540 | SIDIAP | Spain | Incidence of knee OA by ICD-10 code |
Knee OA: Most vs. least deprived area aIRR = 1.23 (1.19–1.28) |
Abbreviations: aβ = adjusted parameter estimate, ADL = activities of daily living, aOR = adjusted odds ratio, aRII= adjusted relative index of inequality, AViKA = Adding Value in Knee Arthroplasty, CI= confidence interval, ICD = International Classification of Diseases, IR= annual incidence rate, IRR = incidence rate ratio, JoCo OA = Johnston County Osteoarthritis Project, KOOS = Knee Injury and Osteoarthritis Outcome Score, MSK = musculoskeletal, NHANES = National Health and Nutrition Examination Survey, QOL = quality of life, rKOA = radiographic knee osteoarthritis, RR = rate ratio, SASH = Somerset and Avon Survey of Health, SES = socioeconomic status, SIDIAP = System for the Development of Research in Primary Care, sxKOA = symptomatic knee osteoarthritis, UK = United Kingdom, US = United States, WOMAC= Western Ontario and McMaster Universities Osteoarthritis Index