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Table 5 Costs generated by method of reporting: agreement between the OCC-Q questionnaire and administrative databases*†

From: Good agreement between questionnaire and administrative databases for health care use and costs in patients with osteoarthritis

  OCC-Q ($) Mean ± SD Databases ($) Mean ± SD ρ c Mean difference ($) (95% CI)§ 95% limits of agreement ($)||
GP services      
Co-payments 37.59 ± 29.46 29.62 ± 29.53 0.502 -7.97 (-16.39, 0.46) -67.28 to 51.35
Societal cost 79.84 ± 60.84 67.08 ± 61.38 0.502 -14.24 (-30.92, 2.44) -131.63 to 103.15
Medications      
Subsidy      
Paracetamol n = 49 2.96 ± 2.90 3.57 ± 6.36 0.358 0.60 (-1.00, 2.21) -10.58 to 11.78
   Imputed (n = 50) 3.02 ± 2.93 3.50 ± 6.32 0.360 0.58 (-1.02, 2.13) -10.53 to 11.64
Opiates 1.89 ± 6.36 3.83 ± 11.54 0.645 1.94 (-0.24, 4.13) -13.45 to 17.33
Paracetamol & opiates 3.20 ± 7.16 2.84 ± 7.50 0.807 -0.36 (-1.66, 0.93) -9.48 to 8.75
NSAID n = 45 4.12 ± 7.05 3.66 ± 7.45 0.876 -0.44 (-1.52, 0.64) -7.63 to 6.74
   Imputed (n = 50) 4.74 ± 7.60 3.59 ± 7.11 0.789 -1.10 (-2.42, 0.22) -10.40 to 8.19
Pantoprazole 0.43 ± 2.13 0.67 ± 2.74 0.716 0.24 (-0.28, 0.77) -3.44 to 3.92
Omeprazole n = 45 2.89 ± 6.34 17.30 ± 50.56 0.140 14.41 (0.30, 28.51) -77.62 to 106.44
   Imputed (n = 50) 3.56 ± 6.35 19.03 ± 49.32 0.137 15.45 (2.42, 28.48) -76.24 to 107.15
Amitriptyline 0.45 ± 1.72 0.30 ± 1.27 0.225 -0.15 (-0.68, 0.36) -3.91 to 3.61
Co-payment      
Paracetamol n = 40 5.08 ± 16.52 0.83 ± 1.36 -0.006 -4.25 (-9.57, 1.07) -36.79 to 28.59
   Imputed (n = 50) 8.88 ± 36.86 0.66 ± 1.26 -0.008 -12.34 (-22.55, -2.13) -84.19 to 59.51
Opiates 0.30 ± 0.91 0.40 ± 1.18 0.716 0.10 (-1.24, 0.32) -1.48 to 1.68
Paracetamol & opiates¶ 1.39 ± 4.05 0.48 ± 1.85 0.168 -0.91 (-2.06, 0.24) -9.00 to 7.18
NSAID n = 44 1.23 ± 4.98 0.93 ± 1.66 0.151 -0.30 (-1.77, 1.18) -9.76 to 9.21
   Imputed (n = 50) 1.18 ± 4.68 0.88 ± 1.61 0.148 -0.28 (-1.58, 1.02) -9.41 to 8.85
Pantoprazole 0.12 ± 0.59 0.12 ± 0.59 1.00 0.00 (0.00, 0.00) 0.00 to 0.00
Omeprazole n = 44 0.82 ± 2.45 0.47 ± 1.11 0.176 -0.34 (-1.08, 0.40) -5.22 to 4.54
   Imputed (n = 50) 1.06 ± 3.31 0.42 ± 1.05 0.143 -0.54 (-1.22, 0.14) -5.34 to 4.26
Amitriptyline 0.18 ± 0.72 0.06 ± 0.42 -0.031 -0.12 (-0.36, 0.12) -1.81 to 1.58
Total medication cost n = 31 24.36 ± 25.04 41.00 ± 59.76 0.144 -16.63 (-38.49, 5.23) -135.82 to 102.56
   Imputed (n = 50) 30.40 ± 39.83 36.79 ± 52.90 0.152 5.70 (-11.51, 22.91) -115.41 to 126.81
Hospital-based services      
Emergency visits 13.36 ± 66.11 13.36 ± 66.11 1.00 0.00 0.00 to 0.00
OA-related inpatient events 292.00 ± 2064.73 292.00 ± 2064.73 1.00 0.00 0.00 to 0.00
Orthopaedics 50.41 ± 80.76 37.80 ± 81.51 0.316 -9.45 (-35.68, 16.78) -194.03 to 175.13
Rheumatology 16.76 ± 71.33 12.57 ± 65.71 0.701 -4.19 (-12.61, 4.23) -63.45 to 55.07
Medical imaging n = 48 24.15 ± 35.57 21.13 ± 34.23 0.488 -3.02 (-12.67, 6.63) -70.94 to 64.90
Total hospital costs 393.53 ± 2054.51 376.87 ± 2057.66 0.998 -16.66 (-48.01, 14.68) -237.25 to 203.93
Total health care cost n = 31 209.27 ± 167.95 192.51 ± 183.74 0.606 -16.75 (-73.84, 40.33) -328.01 to 294.51
   Imputed (n = 50) 513.20 ± 2132.22 485.46 ± 2105.69 0.997 -34.05 (-76.65, 8.55) -333.83 to 265.73
  1. *All monetary values are in 2009 New Zealand dollars (NZD), with a conversion rate to US dollars (USD) at 2009 purchasing power parity of $1 NZD = $0.63 USD.
  2. †OCC-Q datasets are complete (n = 50) unless indicated otherwise (Database records have no missing values), n < 50 = complete case analysis for OCC-Q with the same cases dropped from the Database, Imputed n = 50 indicates the mean ± SD for OCC-Q values are estimated from 5 imputed datasets combined; ρc, mean difference 95% CI, and 95% limits of agreement are estimated using the first imputed dataset
  3. ρc = Lin's concordance correlation coefficient
  4. §95% CI assumes a normal distribution
  5. ||95% limits of agreement
  6. ¶Combination product
  7. Abbreviations: OCC-Q, Osteoarthritis Cost and Consequences Questionnaire; GP, general practitioner; SD, standard deviation; CI, confidence interval; NSAID, non-steroidal anti-inflammatory drug: diclofenac, voltaren, ibuprofen, naproxen; Opiates: codeine, DHC continus