epidemiology-methodslisted

# Epidemiology Methods in R ## Overview Comprehensive epidemiological analysis methods covering study designs, measures of association, confounding control, propensity scores, and causal inference using R. ## Measures of Association ### Risk and Rate Measures ```r library(epiR) # 2x2 table data # Outcome: +/- # Exposure: +/- table_data <- matrix(c(a, b, c, d), nrow = 2, byrow = TRUE) colnames(table_data) <- c("Disease+", "Disease-") rownames(table_data) <- c("Exposed", "Unexposed") # Risk ratio, risk difference, odds ratio epi.2by2(as.table(table_data), method = "cohort.count") # For case-control epi.2by2(as.table(table_data), method = "case.control") # For cross-sectional epi.2by2(as.table(table_data), method = "cross.sectional") ``` ### Incidence Rates ```r library(Epi) # Person-time calculations # Create Lexis object lex <- Lexis( entry = list(age = entry_age, cal = entry_date), exit = list(cal = exit_date), exit.status = event, data = cohort_data ) # Split person-time by age bands lex_split <- splitLexis(lex, breaks = seq(30, 80, by = 10), time.scale = "age") # Calculate rates rates <- tapply(status(lex_split, "exit"), timeBand(lex_split, "age", type = "factor"), function(x) sum(x == 1)) pyrs <- tapply(dur(lex_split), timeBand(lex_split, "age", type = "factor"), sum) # Incidence rates rates / pyrs * 1000 ``` ### Standardized Rates ```r library(epitools) # Direct standardization ageadju