Skip to main content
. 2021 Jan 7;21:12. doi: 10.1186/s12874-020-01205-6

Table 2.

Scenarios for the simulation set-up

Number of trials per comparison
 typical loop NO = 1, NP = 3,  OP = 4
Trial size (ni,kE=ni,kC=ni in trial i)
 <  50 (small) ni~U(12, 39) placebo-controlled trials
ni~U(15, 49) old-controlled trials
 >  100 (moderate)

ni~U(102, 187) placebo-controlled trials

ni~U(128, 241) old-controlled trials

Initial event rates of the control arm in trial  i
 low events pi,PC,0~U0.050.09 placebo-controlled trials
pi,OC,0~U0.100.15 old-controlled trials
 frequent events pi,PC,0~U0.270.40 placebo-controlled trials
pi,OC,0~U0.630.76 old-controlled trials
Unbalanced risk of missing outcome data (qi,kE<qi,kC in trial i)
 moderate qi,kE~U0.050.10, qi,kC~U0.110.20
 large qi,kE~U0.210.30, qi,kC~U0.310.40
Missingness mechanisms via log IMOR
 informative φi, P~TN(μ =  −  log (2), σ2 = 1, a =  log (1))
φi, k~TN(μ =  log (2), σ2 = 1, a =  log (1)) k = N, O
Treatment effects
 basic parameters LORNP =  ln (2), LOROP =  ln (1.5)
 functional parameter LORNO = LORNP − LOROP (consistency equation)
Common between-trial variance
 predictive distribution

τ2~LΝ(−3.95, 1.342) (small)

τ2~LΝ(−2.56, 1.742) (substantial)

Note: C Control; E Experimental arm; IMOR Informative missingness odds ratio; LN Log-normal distribution; LOR Log odds ratio; N New intervention; O Old intervention; P Placebo; T Truncated normal distribution; U Uniform distribution

Typical loop as defined by Veroniki et al. [32]

Using predictive log-normal distributions that correspond to all-cause mortality and generic health setting for small and substantial between-trial variance, respectively [33]