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Table 4 Effect of added reference items and the discrepancy rule on the success rate of treatment

From: The index ‘Treatment Duration Control’ for enabling randomized controlled trials with variation in duration of treatment of chronic pain patients

Occasion of evaluation Mode of adding reference items n TDC ≤ −0.379 n TDC > −0.379 n discrepancy rule n S-Tx n U-Tx Success rate (%)
PEM A 100 18 8 92 26 78.0
PEM NA 100 18 8 92 26 78.0
EM s-A 93 25 4 89 29 75.4
EM c-A 96 22 8 88 30 74.6
EM NA 98 20 6 92 26 78.0
LM s-A 70 48 4 66 52 55.9
LM c-A 78* 40* 9* 69* 49* 58.5*
LM NA 79* 39* 6* 73* 45* 61.9*
  1. Occasion of evaluation of treatment (Tx) success rate: PEM (clinician); EM, (assessor); LM, (assessor; cf legend of Figure 2). Mode of adding reference items: A, added (by clinician); s-A, separately added by clinician and by investigator (based on data from assesor), and only the added reference items from the assessor are considered in the Tx evaluation; c-A, continually added by clinician and subsequently by the investigator (based on data from assessor), and all added reference items are considered in the Tx-outcome; NA, no addition. n TDC ≤ −0.379 and n TDC > −0.379: number of patients for which TDC ≤ −0.379 or TDC > −0.379 respectively. n discrepancy rule: number of patients with application of the ‘discrepancy rule’ (see text, section ‘treatment procedure’). n S-Tx and n U-Tx: number of patients with a successful Tx and a unsuccessful Tx respectively. Note that n S-Tx = [(n TDC ≤ −0.379) – (n discrepancy rule)], and n U-Tx = [(n TDC > −0.379) + (n discrepancy rule)]. Note also that the application of the discrepancy rule was occasional, i.e. for 3.4-7.6% of the patients.
  2. Success rate (%) = (n S-Tx/118)×100% (118 = total number of patients).
  3. *, values based on n = 89 patients who entered the follow-up at EM according to separately added reference items (s-A) from the assessor (the mode of addition used in the RCT of the present study). Because the number of patients entering the follow-up at EM would have been slightly larger according to NA (n = 92) than actually occurring according to s-A (n = 89), the success-rate (n S-Tx) at LM might be slightly underestimated for the mode NA. The success-rate at LM is approximately correctly estimated for the mode c-A as the number of patients entering the follow-up was nearly the same for c-A (n = 88) as for s-A (n = 89). Note that regardless of a possible underestimation of n S-Tx for LM, NA, the value of success-rate is the smallest for LM, s-A.