Table 1 Sequence symmetry results of the 1000 simulations for different scenarios of medicine utilisation trends and effect sizes, for a population size of 1 million and 20% population prevalence of use of each drug
Crude sequence ratio | Adjusted sequence ratio | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Medicine utilisation scenario | Pairs (N) | Null SR | Crude SR (95% CI) | Cover-age (%) | Power* (%) | Relative bias (%) | Adjusted SR (95% CI) | Cover-age (%) | Power* (%) | Relative bias (%) |
Expected ASR = 1.0 | ||||||||||
No trend | 3597 | 1.00 | 1.00 (0.94-1.07) | 95.5 | 2.2 | 0.38 | 1.00 (0.94-1.07) | 95.6 | 2.1 | 0.38 |
Gradual | 656 | 0.85 | 0.86 (0.73-1.00) | 47.6 | 0.0 | −13.85 | 1.00 (0.85-1.17) | 94.4 | 2.1 | 1.02 |
Constant | 1604 | 0.84 | 0.84 (0.76-0.93) | 7.3 | 0.0 | −15.34 | 1.00 (0.90-1.11) | 95.2 | 1.9 | 0.46 |
Rapid | 1811 | 0.88 | 0.88 (0.80-0.97) | 22.4 | 0.0 | −11.71 | 1.00 (0.91-1.10) | 96.1 | 2.2 | 0.46 |
Expected ASR = 1.2 | ||||||||||
No trend | 3956 | 1.00 | 1.20 (1.13-1.28) | 94.2 | 100.0 | 0.35 | 1.20 (1.13-1.28) | 94.7 | 100.0 | 0.36 |
Gradual | 717 | 0.85 | 1.03 (0.88-1.19) | 42.8 | 5.1.0 | −13.51 | 1.21 (1.03-1.40) | 94.6 | 66.4 | 1.43 |
Constant | 1754 | 0.84 | 1.01 (0.92-1.11) | 4.8 | 2.9 | −15.52 | 1.20 (1.09-1.32) | 94.8 | 96.0 | 0.23 |
Rapid | 1983 | 0.88 | 1.05 (0.96-1.15) | 18.9 | 19.8 | −11.85 | 1.20 (1.09-1.31) | 94.2 | 96.8 | 0.31 |
Expected ASR = 1.5 | ||||||||||
No trend | 4498 | 1.00 | 1.50 (1.41-1.59) | 95.2 | 100.0 | 0.19 | 1.50 (1.41-1.59) | 95.6 | 100.0 | 0.18 |
Gradual | 806 | 0.85 | 1.29 (1.11-1.48) | 41.0 | 92.2 | −13.82 | 1.51 (1.30-1.73) | 95.6 | 100.0 | 1.07 |
Constant | 1973 | 0.84 | 1.27 (1.15-1.39) | 3.9 | 100.0 | −15.29 | 1.50 (1.37-1.65) | 96.0 | 100.0 | 0.50 |
Rapid | 2238 | 0.88 | 1.32 (1.21-1.44) | 16.6 | 100.0 | −11.67 | 1.50 (1.38-1.64) | 95.6 | 100.0 | 0.50 |
Expected ASR = 2.0 | ||||||||||
No trend | 5395 | 1.00 | 2.00 (1.90-2.12) | 94.2 | 100.0 | 0.42 | 2.00 (1.90-2.12) | 94.7 | 100.0 | 0.42 |
Gradual | 957 | 0.85 | 1.72 (1.49-1.96) | 36.7 | 100.0 | −13.92 | 2.01 (1.74-2.29) | 95.2 | 100.0 | 0.95 |
Constant | 2338 | 0.84 | 1.69 (1.55-1.84) | 2.4 | 100.0 | −15.29 | 2.00 (1.83-2.19) | 95.7 | 100.0 | 0.50 |
Rapid | 2660 | 0.88 | 1.76 (1.62-1.91) | 11.2 | 100.0 | −11.69 | 2.00 (1.85-2.17) | 96.1 | 100.0 | 0.48 |
Expected ASR = 3.0 | ||||||||||
No trend | 7197 | 1.00 | 3.00 (2.85-3.17) | 95.1 | 100.0 | 0.26 | 3.00 (2.85-3.17) | 95.1 | 100.0 | 0.27 |
Gradual | 1260 | 0.85 | 2.57 (2.26-2.90) | 29.2 | 100.0 | −13.92 | 3.01 (2.65-3.41) | 95.8 | 100.0 | 0.98 |
Constant | 3074 | 0.84 | 2.54 (2.35-2.75) | 0.9 | 100.0 | −15.00 | 3.01 (2.79-3.26) | 95.4 | 100.0 | 0.82 |
Rapid | 3510 | 0.88 | 2.63 (2.45-2.84) | 8.6 | 100.0 | −11.72 | 3.00 (2.79-3.24) | 93.5 | 100.0 | 0.44 |
Expected ASR = 0.6 | ||||||||||
No trend | 4799 | 1.00 | 0.60 (0.56-0.64) | 94.0 | 100.0 | −0.03 | 0.60 (0.56-0.64) | 94.0 | 100.0 | −0.03 |
Gradual | 893 | 0.85 | 0.51 (0.44-0.58) | 32.6 | 100.0 | −14.61 | 0.60 (0.52-0.68) | 95.7 | 100.0 | 0.13 |
Constant | 2187 | 0.84 | 0.51 (0.46-0.55) | 23 | 100.0 | −15.54 | 0.60 (0.55-0.66) | 96.3 | 100.0 | 0.21 |
Rapid | 2456 | 0.88 | 0.53 (0.48-0.57) | 12.1 | 100.0 | −11.90 | 0.60 (0.55-0.65) | 96.3 | 100.0 | 0.24 |
Expected ASR =0.80 | ||||||||||
No trend | 4048 | 1.00 | 0.80 (0.75-0.85) | 95.7 | 100.0 | 0.11 | 0.80 (0.75-0.85) | 95.7 | 100.0 | 0.10 |
Gradual | 745 | 0.85 | 0.68 (0.58-0.79) | 39.4 | 100.0 | −14.30 | 0.80 (0.68-0.92) | 95.5 | 86.3 | 0.51 |
Constant | 1823 | 0.84 | 0.68 (0.61-0.74) | 4.8 | 100.0 | −15.49 | 0.80 (0.73-0.88) | 95.0 | 99.9 | 0.27 |
Rapid | 2054 | 0.88 | 0.70 (0.64-0.77) | 15.8 | 100.0 | −12.17 | 0.80 (0.73-0.87) | 95.6 | 99.9 | −0.07 |