Characteristics of included studies
| Author /year | Country | Study design and population | Yrs f/u | Method of NAFLD diag* | Method of measuring alcohol consumption | Definition of moderate consumption studied as RF | Study outcomes of interest and event no | Adjustments of interest considered | Adjusted HRs/OR/ mean differences for liver events with 95% CI and p values | Risk of bias |
| Åberg 201956 | Finland | Retrospective data linkage cohort analysis NAFLD population 6462, mean age 53 years, 60% M | 10.9 | FLI>30 | Questionnaire at cohort entry | <50 g/day in 10 g categories with abstinence as reference | Composite non-fatal and fatal liver disease 58 events | ? unclear other than age, sex | Per increase in 10 g of alcohol per day versus abstinence HR 1.43 (1.12 to 1.82) p=0.004 | High |
| Åberg et al 2020 57 | Finland (FINRISK Health survey) | Retrospective data linkage cohort analysis NAFLD population 8345, mean age 53.7 years, 60% M | 11.1 | FLI>60 | Questionnaire at cohort entry (recall for past month) | <50 g/day in 10 g categories with abstinence as reference | Composite non-fatal and fatal liver disease 152 events | Age, sex, smoking, T2DM | g alcohol/day versus abstinence 0–9 hour 1.38 (0.74 to 2.58) 10–19 hour 2.18 (1.04 to 4.53) 20–29 hour 3.62 (1.67 to 7.76) 30–39 hour 3.53 (1.53 to 8.14) 40–49 HR 8.79 (3.95 to 19.56) | Low |
| Ajmera et al 2018 58 | USA | Retrospective analysis of longitudinal cohorts within NASH CRN NAFLD population 285, mean age 47 years, 30% M | 3.9 | Liver biopsy | Questionnaire at cohort entry (Skinner lifetime drinking history) | <2 drinks per day and excluded if >6 drinks on 1 occasion ≥monthly | Histological resolution or progressionon follow-up biopsy | Age, sex, race, smoking | Persistent moderate drinkers versus abstinence* resolution of NASH: OR 0.32 (0.11 to 0.92) p=0.04 fibrosis progression: adj mean diff 0.00 (−0.29 to 0.29) p=0.99 | Mod |
| Chang et al 2019 59 | South Korea (Kangbuk Samsung Health Study) | Prospective population cohort NAFLD population 58 927, mean age 37.7, 82% M | 4.9 | US | Questionnaire at each study visit (annual or biennial) | 10–19.9 g/day (F) 10–29.9 g/day (M) (low 1–9.9 g/day) | Fibrosis progress as estimated by high indirect serum scores** | Age, sex, BMI, smoking, exercise level, education, T2DM, BP | Mod versus abstinence† (repeat observations) Fib4: HR 1.33 (1.13 to 1.57) NFS: HR 1.37 (1.23 to 1.52) low versus abstinence (repeat observations) Fib 4: HR 1.08 (0.91 to 1.27) NFS: HR 1.14 (1.02 to 1.27) | Low |
| Ekstedt et al 2009 60 | Sweden | Retrospective cohort NAFLD population 71, mean age 47.3, 72% M | 13.8 | US and liver biopsy | Questionnaire AUDIT-C and interview at follow-up | g/day—no upper limit defined as ‘moderate’ | Fibrosis progress on follow-up biopsy | Age, sex, BMI, T2DM, fibrosis at baseline | Increasing alcohol g/week versus abstinence OR 1.012 (1.000 to 1.025) p=0.055 | Low |
| Kawamura et al 201661 | Japan | Prospective cohort NAFLD population 9959, mean age 49, 87% M (included 18 patients >70 g alcohol/day defined as ARLD) | 5.4 | US | Questionnaire at baseline and every 6 months | g/day in categories with <20 g/day as reference | HCC on imaging | Age, sex, BMI, T2DM, serum markers | g/day alcohol versus <20 g/day 20–39 hour 0.90 (0.11 to 7.90) p=0.919 ≥40–69 hour 2.48 (1.01 to 6.05) p=0.047 >70 hour 12.61 (5.68 to 28.00) p=0.001 | Low |
*Note multiple differences in means and OR presented for different histological and biochemical outcomes between abstainers, persistent moderate drinkers, and changes in alcohol consumption between biopsies. Presented data represent histological outcomes of potential clinical prognostic significance within the remit of this review comparing persistent moderate drinking to abstinence.
†Multiple HR presented in paper for different score outcomes for single and repeated outcome measures looking at intermediate/high or high-risk scores in low and moderate drinkers and different subgroups. Presented data represent outcomes best in keeping with remit of this review using widely used indirect serum markers of liver fibrosis.
‡Scores used to estimate fibrosis progression were the Fib4 score, NAFLD fibrosis score (NFS) and AST to platelet ratio index (APRI) score.
ARLD, alcohol-related liver disease; AUDIT-C, alcohol use disorders identification test - consumption; BMI, body mass index; BP, blood pressure; CRN, clinical research network; FINRISK, Finland cardiovascular risk study; FLI, Fatty Liver Index; g, grams; HCC, hepatocellular carcinoma; M, Male; NAFLD, non-alcohol-related fatty liver disease; NASH, non-alcohol related steatohepatitis; RF, risk factor; T2DM, type 2 diabetes mellitus; US, hepatic ultrasound; Yrs, years.