Stead · The Cochrane database of systematic reviews 2013 · systematic review and meta-analysis of randomized controlled trials · n=42 trials (>31,000 participants)

Physician advice for smoking cessation.

Cited 1923 times in the scientific literature.

Level 1 - systematic review of randomized trials

Systematic review and meta-analysis of randomized controlled trials

PubMed 23728631 · doi:10.1002/14651858.CD000165.pub4 · record verified 2026-08-29

What was done

Authors searched the Cochrane Tobacco Addiction Group trials register and Latin American databases through early 2013 for randomized controlled trials assessing physician advice for smoking cessation. Eligible trials evaluated medical practitioner advice with abstinence assessed at least six months post-intervention. Data were extracted in duplicate. The primary outcome was smoking abstinence at six or more months, using biochemically validated rates where available and treating individuals lost to follow-up as smokers. Risk ratios were pooled using Mantel-Haenszel fixed-effect meta-analysis.

What was found

The review identified 42 randomized trials conducted between 1972 and 2012 encompassing over 31,000 smokers, primarily in primary care settings. Pooled results from 17 trials showed that brief advice significantly increased quit rates compared to no advice or usual care (RR 1.66, 95% CI 1.42 to 1.94). More intensive interventions compared to no advice yielded an RR of 1.84 (95% CI 1.60 to 2.13; 11 trials). Direct comparisons of intensive versus minimal advice showed a modest advantage for intensive advice (RR 1.37, 95% CI 1.20 to 1.56). Only one trial assessed mortality, finding no statistically significant difference in death rates at 20-year follow-up.

Why it matters

Even brief, routine advice from a physician yields an absolute increase in cessation rates of 1 to 3 percentage points over baseline unassisted quit rates (2 to 3%). Scaled across routine healthcare encounters, this low-cost intervention can produce meaningful population-level health benefits.

Limits

The absolute effect size remains small (1 to 3% absolute increase). Long-term health outcomes and mortality data are sparse, with only one included study evaluating 20-year mortality. Variations in trial settings, definitions of intensive interventions, and reporting of biochemical validation across trials conducted over four decades introduce heterogeneity.

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