Table 4

Perceived effectiveness of pictorial warnings: mean weighted effect sizes (d) and heterogeneity statistics

Nkd95% CIp ValueQp ValueI2
Perceived effectiveness of warning to…
 Motivate me/others to not start smoking394641.03(0.30 to 1.75)0.0062510.00199
 Motivate me to cut down on smoking45020.41(0.07 to 0.75)0.0230.0964
 Motivate me to quit smoking5986100.79(0.41 to 1.18)0.0013560.00197
 Motivate others to quit smoking366751.09(0.39 to 1.80)0.0022380.00198
 Motivate me/others to not smoke (composite)380730.24(0.18 to 0.31)0.00120.470
 Be generally effective (no referent)340541.00(0.20 to 1.80)0.013440.00199
 Be effective for me/others (scale)451240.52(0.07 to 0.97)0.02630.00195
 Deter giving cigarettes as gift350421.64(1.37 to 1.91)0.001130.00192
  • n, number of participants; k, number of effect sizes; d, standardised mean difference (pooled effect size).