Objective A systematic review to assess the equity impact of interventions/policies on youth smoking.

Data sources Biosis, Cinahl, Cochrane Library, Conference Proceedings Citation Index, Embase, Eric, Medline, Psycinfo, Science Citation Index Expanded, Social Sciences Citation Index and tobacco control experts. Published January 1995 to October 2013.

Study selection Primary studies of interventions/policies reporting smoking-related outcomes in youth (11–25 years) of lower compared to higher socioeconomic status (SES).

Data extraction References were screened and independently checked. Studies were quality assessed; characteristics and outcomes were extracted.

Data synthesis A narrative synthesis by intervention/policy type. Equity impact was assessed as: positive (reduced inequity), neutral (no difference by SES), negative (increased inequity), mixed (equity impact varied) or unclear.Thirty-eight studies of 40 interventions/policies were included: smokefree (12); price/tax (7); mass media campaigns (1); advertising controls (4); access controls (5); school-based programmes (5); multiple policies (3), individual-level cessation support (2), individual-level support for smokefree homes (1). The distribution of equity effects was: 7 positive, 16 neutral, 12 negative, 4 mixed, 1 unclear. All 7 positive equity studies were US-based: price/tax (4), age-of-sales laws (2) and text-messaging cessation support (1). A British school-based intervention (A Stop Smoking in Schools Trial (ASSIST)) showed mixed equity effects (neutral and positive). Most neutral equity studies benefited all SES groups.

Conclusions Very few studies have assessed the equity impact of tobacco control interventions/policies on young people. Price/tax increases had the most consistent positive equity impact. There is a need to strengthen the evidence base for the equity impact of youth tobacco control interventions.