Counseling interventions were analyzed using the predetermined 4-level classification of intervention intensity (Figure 1). Only 1 study assessed a brief inpatient intervention with no subsequent support (intensity 1).19 This was not more effective than usual care (OR, 1.16; 95% CI, 0.80-1.67). Eight studies tested a longer inpatient intervention with no contact after discharge (intensity 2).9,11,12,17,21,24,25,38 There was no benefit in the pooled analysis of these studies (OR, 1.08; 95% CI, 0.89-1.29). Similarly, no statistically significant benefit was found in a pooled analysis of 6 studies that tested an inpatient intervention with contacts continuing for up to 1 month after discharge (intensity 3)20,22,28,29,32,33(OR, 1.09; 95% CI, 0.91-1.30). There was substantial heterogeneity (I2 = 53%) in the results of 18 studies that tested the highest intensity intervention (intensity 4), consisting of inpatient counseling that continued for more than 1 month after discharge.6,10,11,13,14,16,18- 20,23,26,27,30,31,34,37,39 However, 1 study was an extreme outlier.15 It reported a very large effect (OR = 49) due to an unusually low cessation rate in the control condition. It also had a very high dropout rate across conditions. Excluding this trial from the meta-analysis reduced the heterogeneity (I2 = 35%). The level 4 intervention increased quit rates in the pooled estimate (OR, 1.65; 95% CI, 1.44-1.90).