TABLE 2.
Definition of aspirin user, aspirin dose and adjusted variables.
| Study | Definition of aspirin user | Aspirin dose | Adjusted variables |
|---|---|---|---|
| Jacobs et al. (2012)41 | Use 30 or 31 days per month of either low-dose or adult-strength aspirin | Low-dose or adult-dose aspirin | Age, sex, race, education, smoking, history of heart disease, stroke, diabetes, hypertension, cholesterol-lowering drug use (current), aspirin use in the year 1982, nonsteroidal anti-inflammatory drug use, and history of colorectal endoscopy (ever) |
| Sahasrabuddhe et al. (2012)21 | Self-reported aspirin use | Monthly (≤2–3 times per month), weekly (1–2 times to 5–6 times per week), or daily use (≥1 times per day) | Age, sex, race, cigarette smoking, alcohol consumption, diabetes, and body mass index |
| Yeh et al. (2014)44 | Retrieved from the pharmacy register data set | NA | Age, sex, extent of liver resection, chronic viral hepatitis status, comorbidities, and the use of drugs such as statin and metformin |
| Petrick et al. (2015)20 | Get from ten US-based prospective cohort studies | NA | Age, sex, race, cohort, body mass index, smoking, drinking, diabetes |
| Li et al. (2016)42 | Administered at least 100 mg/day of aspirin continuously for more than 3 months | ≥100 mg/day | Age, gender, date of HCC diagnosis, Child-Pugh score, following treatment after the initial TACE, tumor size, tumor number, vascular invasion, and metastasis the initial date of HCC diagnosis |
| Yang et al. (2016)22 | Having two or more aspirin prescriptions recorded prior to the index date of the individual | NA | Body mass index, smoking status, alcohol-related disorders, hepatitis B or C virus infection, diabetes, rare metabolic disorders, and use of paracetamol, antidiabetic medications, and statins |
| Hwang et al. (2018)19 | Used more than 365 DDDs of aspirin | ≥365 DDDs | Age, sex, body mass index, health behaviors (cigarette smoking, alcohol consumption, and physical activity), concurrent medication, category of blood pressure, fasting plasma glucose and total cholesterol, socioeconomic status, and Charlson comorbidity index score |
| Simon et al. (2018)36 | ≥standard-dose [325-mg] tablets per week | ≥325 mg/week | Body mass index, alcohol intake, smoking status, physical activity, diabetes, hypertension, dyslipidemia, Regular multivitamin use, regular use of oral antidiabetic medications, regular use of statins, regular use of non-aspirin nonsteroidal anti-inflammatory drugs |
| Du et al. (2019)40 | Taking 100 mg/d aspirin within 7 days | 100 mg/d | Gender, AST, INR, surgical method, postoperative early aspirin |
| Lee et al. (2019)34 | Received daily aspirin for 90 or more days | ≤100 mg/d | Age, male sex, liver cirrhosis, diabetes, hyperlipidemia, hypertension, statin use, metformin use, and Nucleoside analogues use |
| Tsoi et al. (2019)35 | Adults with aspirin prescription for at least 6 months | The median dose of aspirin was 80 mg | Age, sex |
| Young et al. (2019)43 | Continuous use of aspirin for at least 30 days before tumor recurrence | NA | Age, sex, and other covariates |
| Liao et al. (2020)37 | NA | NA | Age, sex, comorbidities, drugs, diagnosis year, and index year |
| Shen et al. (2020)24 | At least once per week over a duration of 3 months or more | NA | Age, gender, race, education, household income, and marital status |
| Shin et al. (2020)38 | Who were treated with aspirin more than 6 months | 100 mg/day | NA |
| Simon et al. (2020)39 | Identified by their first filled prescriptions for 90 or more consecutive doses of aspirin | Low-dose aspirin (≤160 mg) | Sex; continuous years since diagnosis of hepatitis B or hepatitis C; liver disease severity, hypertension, obesity, or alcohol abuse or misuse; and use of insulin, metformin, and statins, and so on |
US, United States; HCC, hepatocellular carcinoma; AST, aspartate aminotransferase; INR, international normalized ratio; DDD, defined daily dose; NA, not available.