TABLE 1.

Umbrella reviews: study characteristics, main findings and limitations

Author, year; review type, research question	‘a priori’ design; search; study selection; data extraction	Quality assessment	Main findings	Limitations/risks of bias
Anderson, Chisholm, Fuhr, 2009 [14]; ‐ Narrative review ‐ Effectiveness and cost‐effectiveness of policies and programmes to reduce the harm caused by alcohol	‐ ‘a priori’ design: no ‐ search comprehensive: unclear ‐ grey literature: unclear ‐ year of last search: unclear ‐ no. of studies included: 3 reviews, 1 book, 4 individual studies (LMIC: 1) ‐ duplicate study selection and data extraction: no	None. The quality of included studies was not assessed. The strength of the evidence was based on the type of study design of included studies: 1 = more than one systematic review; 2 = one systematic review; 3 = 2 or more randomised controlled trials; 4 = one randomised controlled trial; 5 = observational evidence; 6 = not assessed.	Specific results not presented. Alcohol taxes were found ‘effective’ at reducing alcohol use. Evidence statement: ‐ a meta‐analysis noted a median price elasticity for all beverage types of −0.52 in the short term and −0.82 in the long term, elasticities being lower for beer than for wine or spirits [28]; ‐ a meta‐analysis noted mean price elasticities of −0.46 for beer, −0.69 for wine, and −0.80 for spirits [27].	Non‐systematic and poorly described search strategy; unclear how included studies were selected; no quality assessment; only very broad results presented, which limit usefulness of the review; limited generalizability to LMIC; some evidence statements not supported by evidence cited.
Jackson, Johnson et al., 2010 [15]; ‐ Narrative review ‐ Assessment of the clinical and cost‐effectiveness of (i) measures to detect alcohol misuse amongst adults and young people; (ii) brief interventions to manage alcohol misuse among adults and young people; and (iii) interventions to improve management of England's alcohol market	‐ ‘a priori’ design: no ‐ search comprehensive: unclear ‐ grey literature: no ‐ year of last search: unclear ‐ no. of studies included: unclear (at least 4 reviews seem to have been examined) (LMIC: 0) ‐ duplicate study selection and data extraction: unclear	A quality checklist for reviews was developed. A subjective cut‐off score of 9 criteria fulfilled (of a total of 14) was deemed of higher quality. Assessment not provided; only 3 broad quality scores provided.	Only broad results presented: ‐ a clear relationship between price/tax increases and reductions in the demand for alcohol; ‐ some evidence that young people, binge drinkers and harmful drinkers tended to show a preference for cheaper drinks; ‐ limited evidence that minimum pricing may be effective in reducing alcohol consumption; ‐ one meta‐regression analysis suggested that the higher the relative market share of a beverage, the more inelastic the consumer demand.	Unclear search strategy; limited quality assessment; overly broad conclusions; limited generalizability to LMIC.
Martineau, Tyner et al., 2013 [16]; ‐ Narrative review ‐ Population‐level interventions to reduce alcohol‐related harm	‐ ‘a priori’ design: yes ‐ search comprehensive: yes ‐ grey literature: unclear ‐ year of last search: 2012 ‐ no. of studies included: 3 reviews (LMIC: 0) ‐ duplicate study selection and data extraction: yes	The quality of the reporting was assessed using the AMSTAR tool; assessment not provided; only broad quality scores (high, mid, low) provided.	Overview of 3 reviews suggested that there was clear and consistent evidence that increasing alcohol price or taxation reduced overall consumption; one review indicated that a 10% increase in alcohol prices would lead to a 3%–10% reduction in total consumption [34].	Small number of reviews included; overly broad conclusions; limited quality assessment; limited generalizability to LMIC.
Stockings, Hall et al., 2016 [17]; ‐ Narrative review ‐ Prevention, early intervention, harm reduction, and treatment of substance use in young people	‐ ‘a priori’ design: no ‐ search comprehensive: yes ‐ grey literature: unclear ‐ year of last search: 2012 ‐ no. of studies included: 2 reviews (LMIC: 0) ‐ duplicate study selection and data extraction: unclear	None	Only broad results presented: ‐ increasing alcohol taxation or alcohol price reduced overall alcohol consumption, with a 10% increase in alcohol prices producing a 3–10% reduction in consumption [34]; ‐ scarce evidence regarding the effect of increased taxation on problematic alcohol use; ‐ young people no more or less responsive to price/tax.	Small number of reviews included; overly broad conclusions; no quality assessment; limited generalizability to LMIC.
Burton, Henn et al., 2017 [18]; ‐ Rapid narrative review ‐ Effectiveness and cost‐effectiveness of alcohol control policies	‐ ‘a priori’ design: no ‐ search comprehensive: no ‐ grey literature: unclear ‐ year of last search: 2016 ‐ no. of studies included: 7 reviews, 2 individual studies (LMIC: 0). ‐ duplicate study selection and data extraction: no	Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria. Unclear if the quality of individual studies were assessed beyond their design (e.g. systematic review, RCT, …).	Only broad results presented: − Taxation ‐ increased tax was associated with a proportionate reduction in alcohol consumption; ‐ all alcohol drinkers can be targeted at beverage types; − Minimum pricing ‐ applies only to alcohol, which is cheap relative to its strength; moderate drinkers and the on‐trade are minimally affected.	Search strategy poorly described and not comprehensive; broad conclusions; unclear quality assessment of individual studies; limited generalizability to LMIC.
Siegfried, Parry, 2019 [19]; ‐ Narrative review ‐ Alcohol control interventions included in the 2010 World Health Organization Global Strategy to Reduce the Harmful Use of Alcohol	‐ ‘a priori’ design: yes ‐ search comprehensive: yes ‐ grey literature: yes ‐ year of last search: 2017 ‐ no. of studies included: 7 reviews (LMIC: 0) ‐ duplicate study selection and data extraction: yes	Four ROBIS (Risk of Bias Assessment Tool for Systematic Reviews) domains were used (i) study eligibility criteria; (ii) identification and selection of studies; (iii) data collection and study appraisal; and (iv) synthesis and findings. Only broad scores are presented (high, low or uncertain) without any details.	Only broad results presented. ‐ The evidence for ‘increased pricing and taxation’ was assessed as ‘possibly beneficial,’ with a recommendation for ‘revision with adequate quality assessment, meta‐analysis and regression where possible to account for the potential confounders, and integration of the overall quality into the interpretation of the results.’ Unclear what was meant by ‘beneficial.’ ‐ The evidence for ‘price only (minimum unit pricing)’ was assessed, based on a single review as ‘possibly beneficial’ with recommendations that further implementation of minimum unit pricing occur within a monitoring environment.	Small number of reviews included; included studies limited to those reported between 2006 and 2017; limited reporting of quality assessment of individual studies; overly broad presentations of results; no clear conclusion reported; limited generalizability to LMIC.