Summary tables for APA-style reporting

library(spicy)

spicy’s four reporting helpers cover the full APA Manual 7 table sequence used in empirical articles:

  • table_categorical() and table_continuous() build Table 1 (sample characteristics) and Table 2 (group comparisons);
  • table_continuous_lm() extends Table 2 to the linear-model regime when group means need robust SE, weights, or covariate adjustment;
  • table_regression() builds Table 3 (the coefficient table) from one or several fitted lm() / glm() models.

The four functions share the same output grammar — the same output formats (gt, tinytable, flextable, word, excel, clipboard), the same decimal_mark, digits, p_digits, labels, and align arguments — so a single reporting workflow can move smoothly from descriptive to inferential without juggling different APIs. This vignette focuses on that shared logic; the function-specific articles cover the methodological options in depth.

Choose the right function

Use the function that matches the unit you want to report:

Function Reports Selection grammar Typical additions
table_categorical() Categorical variables (factors, labelled) select, by Chi-squared test, association measure (phi, cramer_v, tau_b, …), confidence interval
table_continuous() Numeric / continuous variables select, by Group-comparison test (Student / Welch t, Wilcoxon, ANOVA, Kruskal–Wallis), effect size (d, g, r, eta², omega²)
table_continuous_lm() Numeric outcomes through one linear model per outcome select, by (single predictor) Robust / cluster-robust / bootstrap / jackknife SE, case weights, additive covariate adjustment, four effect-size families with noncentral CIs
table_regression() One or several fitted lm() / glm() models Fit-first: pass the model object(s) directly, no select / by APA-aligned coefficient table with B, β, 95% CI, p, AME, robust variance, side-by-side and hierarchical layouts

In practice, follow the APA sequence:

  • start with table_categorical() for smoking, education, or activity — APA Table 1 categorical descriptors;
  • use table_continuous() for BMI, well-being, or income — Table 1 continuous descriptors and Table 2 unadjusted group comparisons;
  • switch to table_continuous_lm() when the same comparison must account for survey weights, robust SE, or covariate adjustment;
  • finish with table_regression() once the substantive model is fitted — APA Table 3 with all predictors, factor groupings, reference rows, and (optionally) standardised coefficients, marginal effects, or nested model comparisons.

The first three functions live inside a select / by data-frame grammar; table_regression() is fit-first — you build the model the usual R way (lm() or glm()) and hand the object in. All four share the post-construction grammar (output, labels, digits, decimal_mark, align), so swapping functions never breaks your rendering pipeline.

A shared interface

The three descriptive functions share the same core arguments:

table_categorical(
  sochealth,
  select = c(smoking, physical_activity),
  by = education,
  labels = c("Smoking status", "Regular physical activity"),
  output = "tinytable"
)
#> Found litedown! Enabling r-universe template
Variable Lower secondary Upper secondary Tertiary Total p Cramer's V
n % n % n % n %
Smoking status                                     <.001 .14
    No 179 69.6 415 78.7 332 84.9 926 78.8          
    Yes  78 30.4 112 21.3  59 15.1 249 21.2          
Regular physical activity                                     <.001 .21
    No 177 67.8 310 57.5 163 40.8 650 54.2          
    Yes  84 32.2 229 42.5 237 59.2 550 45.8          
table_continuous(
  sochealth,
  select = c(bmi, wellbeing_score, life_sat_health),
  by = education,
  labels = c(
    bmi = "Body mass index",
    wellbeing_score = "Well-being score",
    life_sat_health = "Satisfaction with health"
  ),
  output = "tinytable"
)
Variable Group M SD Min Max 95% CI n p
LL UL
Body mass index Lower secondary 28.09  3.47 18.20  38.90 27.66 28.51 260 <.001
Upper secondary 26.02  3.43 16.00  37.10 25.73 26.31 534      
Tertiary 24.39  3.52 16.00  33.00 24.04 24.74 394      
Well-being score Lower secondary 57.22 15.44 18.70  97.90 55.33 59.10 261 <.001
Upper secondary 68.97 13.62 26.70 100.00 67.82 70.12 539      
Tertiary 76.85 13.23 40.40 100.00 75.55 78.15 400      
Satisfaction with health Lower secondary  2.71  1.20  1.00   5.00  2.57  2.86 259 <.001
Upper secondary  3.53  1.19  1.00   5.00  3.43  3.63 534      
Tertiary  4.11  1.04  1.00   5.00  4.01  4.21 399      
table_continuous_lm(
  sochealth,
  select = c(bmi, wellbeing_score, life_sat_health),
  by = education,
  weights = weight
)
#> Continuous outcomes by Highest education level
#> 
#>  Variable                       │ M (Lower secondary)  M (Upper secondary) 
#> ────────────────────────────────┼──────────────────────────────────────────
#>  Body mass index                │        25.96                23.39        
#>  WHO-5 wellbeing index (0-100)  │        67.55                80.88        
#>  Satisfaction with health (1-5) │         3.45                 4.39        
#> 
#>  Variable                       │ M (Tertiary)    p     R²    n   
#> ────────────────────────────────┼─────────────────────────────────
#>  Body mass index                │    26.16      <.001  0.13  1188 
#>  WHO-5 wellbeing index (0-100)  │    66.52      <.001  0.19  1200 
#>  Satisfaction with health (1-5) │     3.39      <.001  0.15  1192

The same argument pattern is used in all three cases:

  • select chooses the reported variables;
  • by defines the grouping structure;
  • labels cleans up the row labels;
  • output decides how the result is rendered or exported.

For model-based continuous tables, the same pattern applies, but by must be a single predictor because one linear model is fit per outcome.

table_regression() joins the same labels / output / decimal_mark / digits grammar but is fit-first: rather than expressing model structure inline through select and by, you pass one or several already-fitted lm() or glm() objects:

fit <- lm(
  wellbeing_score ~ age + sex + smoking + physical_activity,
  data = sochealth
)
table_regression(
  fit,
  labels = c(
    age               = "Age (years)",
    sex               = "Sex",
    smoking           = "Smoking status",
    physical_activity = "Regular physical activity"
  ),
  output = "tinytable"
)
Linear regression: wellbeing_score
Variable B SE 95% CI p
LL UL
(Intercept)   64.18 1.69 60.87 67.49 <.001
Age (years)    0.04 0.03 -0.02  0.10  .171
Sex:
Female (ref.)
Male    3.88 0.90  2.11  5.65 <.001
Smoking status:
No (ref.)
Yes   -1.73 1.10 -3.90  0.43  .117
Regular physical activity:
No (ref.)
Yes    2.70 0.91  0.93  4.48  .003
n 1175   
   0.03
Adj.R²    0.02
Note. Linear regression. Std. errors: classical (OLS).

This split is intentional. The descriptive trio (categorical, continuous, continuous_lm) reports the dataselect and by describe what you want to see. table_regression() reports the model — the model formula has already declared which predictors, interactions, polynomials, transformations, splines, and contrasts to report, so passing those again through select / by would duplicate the model object’s information and risk diverging from it.

A practical reporting sequence

A common report contains both table types, often with the same grouping variable. For example, you might first summarize categorical health behaviors, then summarize continuous well-being indicators.

Categorical variables

pkgdown_dark_gt(
  table_categorical(
    sochealth,
    select = c(smoking, physical_activity, dentist_12m),
    by = education,
    labels = c(
      "Smoking status",
      "Regular physical activity",
      "Visited a dentist in the last 12 months"
    ),
    output = "gt"
  )
)

Continuous variables

pkgdown_dark_gt(
  table_continuous(
    sochealth,
    select = c(bmi, wellbeing_score, life_sat_health),
    by = education,
    labels = c(
      bmi = "Body mass index",
      wellbeing_score = "Well-being score",
      life_sat_health = "Satisfaction with health"
    ),
    p_value = TRUE,
    effect_size = TRUE,
    output = "gt"
  )
)

This keeps the reporting structure consistent while still using the function that fits each variable type.

Model-based continuous variables

pkgdown_dark_gt(
  table_continuous_lm(
    sochealth,
    select = c(bmi, wellbeing_score, life_sat_health),
    by = sex,
    vcov = "HC3",
    statistic = TRUE,
    output = "gt"
  )
)

This is the better summary-table path when the article is already organized around simple linear models, weighted analyses, or robust standard errors.

The coefficient table

Once the substantive model is fitted, table_regression() produces the APA Table 3 coefficient summary. The same output argument controls rendering, so the regression table sits in the same reporting pipeline as the descriptive ones above:

fit <- lm(
  wellbeing_score ~ age + sex + smoking + physical_activity,
  data = sochealth
)
pkgdown_dark_gt(
  table_regression(
    fit,
    standardized = "refit",
    show_columns = c("b", "beta", "ci", "p"),
    vcov = "HC3",
    output = "gt"
  )
)

The default footer documents the variance estimator and any methodological choice that affected the rendered values (robust SE, standardisation method, multiplicity correction) so the inferential regime is visible without leaving the table.

Side-by-side reporting of competing specifications (e.g., unadjusted vs. covariate-adjusted, or lm vs. glm) is supported by passing a list of fits:

fit_unadj <- lm(wellbeing_score ~ smoking, data = sochealth)
fit_adj   <- lm(
  wellbeing_score ~ smoking + age + sex + physical_activity,
  data = sochealth
)
pkgdown_dark_gt(
  table_regression(
    list("Unadjusted" = fit_unadj, "Adjusted" = fit_adj),
    show_columns = c("b", "ci", "p"),
    output = "gt"
  )
)

For binary or count outcomes, swap lm() for glm() and request response-scale reporting (odds ratios, incidence rate ratios, etc.):

fit_glm <- glm(
  smoking ~ age + sex + physical_activity,
  data = sochealth,
  family = binomial()
)
pkgdown_dark_gt(
  table_regression(
    fit_glm,
    exponentiate = TRUE,
    show_columns = c("b", "ci", "p", "ame", "ame_ci"),
    output = "gt"
  )
)

Average marginal effects (ame) are useful next to the odds ratio because they report a probability-scale change for each predictor — the quantity most reviewers want to interpret directly.

Choose the output format

All four functions support the same reporting formats:

Output Best use
"default" Quick console review in plain ASCII
"tinytable" Quarto or R Markdown documents
"gt" HTML output with styled reporting tables
"flextable" Office-first workflows; also renders in HTML
"excel" Spreadsheet handoff or downstream editing
"word" Direct .docx export
"clipboard" Fast pasting into another application

Pick the output based on where the table is going, not on the analysis itself. The underlying selection and grouping pattern stays the same.

If you want an object that fits naturally into Word and PowerPoint workflows but can also be rendered in HTML documents, flextable is a good choice:

if (requireNamespace("flextable", quietly = TRUE)) {
  table_continuous(
    sochealth,
    select = c(bmi, wellbeing_score, life_sat_health),
    by = education,
    output = "flextable"
  )
}

Post-process the returned table object

All four summary-table helpers return regular gt, tinytable, or flextable objects, so you can keep styling them with the native package API. This includes table_regression(): nothing about the fit-first interface changes what the rendering engine produces.

Use gt:: functions when you want to keep the gt workflow:

tab <- pkgdown_dark_gt(table_categorical(
  sochealth,
  select = c(smoking, physical_activity),
  by = education,
  labels = c("Smoking status", "Regular physical activity"),
  output = "gt"
))

tab |>
  gt::tab_header(
    title = "Health behaviors by education",
    subtitle = "Categorical summary table"
  ) |>
  gt::tab_source_note(
    gt::md("*Percentages are computed within each education group.*")
  )

Use tinytable:: functions when you want lightweight table-specific styling:

tab <- table_categorical(
  sochealth,
  select = c(smoking, physical_activity),
  by = education,
  labels = c("Smoking status", "Regular physical activity"),
  output = "tinytable"
)

tab |>
  tinytable::style_tt(
    i = 2:3,
    j = 2:5,
    background = "red",
    color = "white",
    bold = TRUE
  )

Use flextable:: functions when you want to keep working toward Office or HTML document output. The example is shown as code here because the dark pkgdown theme is not a reliable preview of the final flextable HTML rendering:

if (requireNamespace("flextable", quietly = TRUE)) {
  tab <- table_continuous(
    sochealth,
    select = c(bmi, wellbeing_score),
    by = education,
    output = "flextable"
  )

  tab |>
    flextable::theme_booktabs() |>
    flextable::autofit() |>
    flextable::fontsize(size = 10, part = "all")
}

Keep the detailed options in the function-specific articles

The dedicated articles go deeper into each function:

  • table_categorical() covers missing values, level filtering, association measures, and one-way frequency-style tables.
  • table_continuous() covers grouped descriptive statistics, parametric and nonparametric tests, and effect sizes.
  • table_continuous_lm() covers estimated marginal means or slopes from linear models, robust / cluster-robust / bootstrap / jackknife variance, case weights, additive covariate adjustment (G-computation or equal-weight), and four effect-size families with noncentral CIs.
  • table_regression() covers single- and multi-model coefficient tables for lm / glm, four standardisation methods, partial effect sizes with noncentral-F CIs, average marginal effects, hierarchical (nested = TRUE) comparisons, multiplicity correction, and response-scale reporting for GLMs.

Use this vignette as the final reporting overview, then consult the function-specific articles when you need the detailed controls.