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*Stata code for replication of the unadjusted anlaysis result reported in Cook JA. An introduction to clinical trials. OUP 1st Edition, 2023.
*21Aug2023
*TOPKAT Trial analysis code used to generated results 
*See publication - Beard et al (HTA, 2020 - DOI: 10.3310/hta24200)
*Chapter 9 Table 9.1 p212 unadjusted analysis of 5 year Oxford Knee Score result
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*Note n, mean and SD values for the two groups are reported in Table 7 of Beard (2020).
 ttesti   233 38.0 10.1 231 37.0 10.6
 
*Note in Beard (2020) raw unadjusted mean difference is state to be 1.02.
*Minor difference in precision of MD changes the p-value from 0.30 to 0.29 
*The following gives the result reported in table 9.1, p212 (Cook, 2023)
 ttesti   233 38.02 10.1 231 37.0 10.6
 
*Rounding accounts for minor difference in reported 95% confidence interval (95% CI) in Beard (2020) versus the calculation here. For example the following gives 95% CI of (-0.86,2.95) 
 ttesti   233 38.023 10.1 231 37.00 10.58
  
*Adjusted analysis in Table 9.1 (Cook 2023) is as reported in Beard (2020), page 29.  
*Replication of the adjusted anlaysis would require access to individual patient data to apply the analysis with individual level adjustment.