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Table 3 Summary of ICC estimates

From: Clustering in surgical trials - database of intracluster correlations

  Centre level Surgeon level  
Outcome N Med Min Max N Med Min Max
EQ-5D 1 wk 1 0.029 - - 1 0.023 - -
EQ-5D 3 m 6 0.001 0 0.06 6 0.015 0 0.071
EQ-5D 12 m 5 0.007 0 0.04 5 0.002 0 0.04
EQ-5D 60 m 3 0.002 0 0.02 3 0.009 0 0.019
Oxford knee score 3 m 3 0.041 0 0.07 3 0.05 0.007 0.068
Oxford knee score 12 m 3 0.027 0.021 0.06 3 0.056 0.047 0.059
Oxford knee score 60 m 3 0.044 0 0.05 3 0.037 0.002 0.051
Operating time 9 0.268 0.072 0.45 8 0.394 0.093 0.514
Length of stay 5 0.104 0.012 0.35 5 0.045 0 0.345
Surgical complications* 4 0.005 0 0.12 4 0.072 0.009 0.084
HRQ overall score 4 m 1 0.058 - - 1 0.114 - -
HRQ overall score 12 m 1 0 - - 1 0 - -
HRQ overall score 24 m 1 0 - - 1 0 - -
RQLS score 3 m 1 0.143 - - 1 0.143 - -
RQLS score 12 m 1 0.058 - - 1 0 - -
Dist. visual acuity (ETDRS) 6 m 1 0.175 - - - - - -
  1. Dist.: distance; EQ-5D: EUROQOL 5D-3L; ETDRS: Early Treatment Diabetic Retinopathy Study; HRQ: Hip replacement Questionnaire; ICC: Intracluster correlation coefficient; N: number of observations; m: month; Max: Maximum; Med: median; Min: minimum; RQLS: REFLUX quality of life measure; wk: week.
  2. * Surgical complication group contains a variety of definition of complications and variable follow-up time periods.