title: Reference curves for the Australian/Canadian Hand Osteoarthritis Index in the middle-aged Dutch population.
abstract: The aim was to establish reference curves of the Australian/Canadian Hand Osteoarthritis Index (AUSCAN), a widely used questionnaire assessing hand complaints.
  
  
  
  Analyses were performed in a population-based sample, The Netherlands Epidemiology of Obesity study (n = 6671, aged 45-65 years). Factors associated with AUSCAN scores were analysed with ordered logistic regression, because AUSCAN data were zero inflated, dividing AUSCAN into three categories (0 vs 1-5 vs >5). Age- and sex-specific reference curves for the AUSCAN (range 0-60; higher is worse) were developed using quantile regression in conjunction with fractional polynomials. Observed scores in relevant subgroups were compared with the reference curves.
  
  
  
  The median age was 56 [interquartile range (IQR): 50-61] years; 56% were women and 12% had hand OA according to ACR criteria. AUSCAN scores were low (median 1; IQR: 0-4). Reference curves where higher for women, and increased moderately with age: 95% percentiles for AUSCAN in men and women were, respectively, 5.0 and 12.3 points for a 45-year-old, and 15.2 and 33.6 points for a 65-year-old individual. Additional associated factors included hand OA, inflammatory rheumatic diseases, FM, socio-economic status and BMI. Median AUSCAN pain subscale scores of women with hand OA lay between the 75th and 90th centiles of the general population.
  
  
  
  AUSCAN scores in the middle-aged Dutch population were low overall, and higher in women than in men. AUSCAN reference curves could serve as a benchmark in research and clinical practice settings. However, the AUSCAN does not measure hand complaints specific for hand OA.
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Féline P B
authors.initials: FPB
authors.lastname: Kroon
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Sofia
authors.initials: S
authors.lastname: Ramiro
authors.affiliation: Department of Statistical Science and MRC Clinical Trials Unit, University College London, London, UK.
authors.forename: Patrick
authors.initials: P
authors.lastname: Royston
authors.affiliation: Department of Clinical Epidemiology.|Department of Medical Statistics and Bio-informatics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Saskia
authors.initials: S
authors.lastname: Le Cessie
authors.affiliation: Department of Clinical Epidemiology.
authors.forename: Frits R
authors.initials: FR
authors.lastname: Rosendaal
authors.affiliation: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.|Department of Clinical Epidemiology.
authors.forename: Margreet
authors.initials: M
authors.lastname: Kloppenburg
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D050823:Hand Joints; D006801:Humans; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000209:etiology; D009426:Netherlands; D010003:Osteoarthritis / Q000175:diagnosis*; D010147:Pain Measurement / Q000592:standards; D012016:Reference Values; D012720:Severity of Illness Index; D012727:Sex Characteristics; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: Hand osteoarthritis; epidemiology; outcomes research