Data Presentation in Clinical Reports

Tables for Clinical Data

Table Design Principles

General guidelines:

Clear, concise title describing table contents
Column headers with units
Row labels aligned left, data aligned appropriately (numbers right, text left)
Footnotes for abbreviations, statistical notation, special cases
Consistent decimal places (typically 1-2 for percentages, 1-3 for continuous variables)
Consistent formatting throughout document

Title placement:

Above table
Numbered sequentially (Table 1, Table 2, etc.)
Descriptive enough to stand alone

Footnote symbols (in order):

*, †, ‡, §, ||, ¶, #
Or use superscript letters (a, b, c...)
Or use superscript numbers if not confused with references

Demographic and Baseline Characteristics Table

Purpose: Describe study population at baseline

Standard format:

Table 1. Baseline Demographics and Clinical Characteristics

Characteristic                  Treatment Group    Control Group    Total
                               (N=150)            (N=145)          (N=295)
─────────────────────────────────────────────────────────────────────────
Age, years
  Mean (SD)                    64.2 (8.5)         63.8 (9.1)       64.0 (8.8)
  Median (IQR)                 65 (58-71)         64 (57-70)       64 (58-71)
  Range                        45-82              43-85            43-85

Sex, n (%)
  Male                         95 (63.3)          88 (60.7)        183 (62.0)
  Female                       55 (36.7)          57 (39.3)        112 (38.0)

Race, n (%)
  White                        110 (73.3)         105 (72.4)       215 (72.9)
  Black/African American       25 (16.7)          28 (19.3)        53 (18.0)
  Asian                        10 (6.7)           8 (5.5)          18 (6.1)
  Other                        5 (3.3)            4 (2.8)          9 (3.0)

BMI, kg/m²
  Mean (SD)                    28.5 (4.2)         28.1 (4.5)       28.3 (4.4)

Baseline HbA1c, %
  Mean (SD)                    8.9 (1.2)          9.0 (1.3)        9.0 (1.2)

Disease duration, years
  Median (IQR)                 6 (3-10)           5 (3-9)          6 (3-10)

Prior medications, n (%)
  Metformin                    135 (90.0)         130 (89.7)       265 (89.8)
  Sulfonylurea                 45 (30.0)          42 (29.0)        87 (29.5)
  Insulin                      20 (13.3)          18 (12.4)        38 (12.9)
─────────────────────────────────────────────────────────────────────────
SD = standard deviation; IQR = interquartile range; BMI = body mass index;
HbA1c = hemoglobin A1c

Key elements:

Sample size for each group (N=)
Continuous variables: mean (SD), median (IQR), range
Categorical variables: n (%)
No p-values for baseline comparisons (debated but generally not recommended)

Efficacy Results Table

Purpose: Present primary and secondary endpoint results

Example:

Table 2. Primary and Secondary Efficacy Endpoints at Week 24

Endpoint                           Treatment      Control        Difference    P-value
                                   (N=150)        (N=145)        (95% CI)
──────────────────────────────────────────────────────────────────────────────────
Primary Endpoint
Change in HbA1c from baseline, %
  Mean (SE)                        -1.8 (0.1)     -0.6 (0.1)     -1.2          <0.001
  95% CI                           (-2.0, -1.6)   (-0.8, -0.4)   (-1.5, -0.9)

Secondary Endpoints
Change in FPG, mg/dL
  Mean (SE)                        -42.5 (3.2)    -15.2 (3.4)    -27.3         <0.001
  95% CI                           (-48.8, -36.2) (-21.9, -8.5)  (-36.4, -18.2)

% achieving HbA1c <7%
  n (%)                            78 (52.0)      25 (17.2)      -              <0.001
  95% CI                           (43.9, 60.1)   (11.4, 24.5)   

Change in body weight, kg
  Mean (SE)                        -3.2 (0.4)     -0.5 (0.4)     -2.7          <0.001
  95% CI                           (-4.0, -2.4)   (-1.3, 0.3)    (-3.8, -1.6)
──────────────────────────────────────────────────────────────────────────────
SE = standard error; CI = confidence interval; HbA1c = hemoglobin A1c; 
FPG = fasting plasma glucose

Statistical presentation:

Point estimates with measures of precision (SE or CI)
p-values (consider adjustment for multiplicity)
Effect size (difference or ratio) with 95% CI
Significance level noted (e.g., p<0.05, p<0.01, p<0.001)

Adverse Events Table

Purpose: Summarize safety data

Example:

Table 3. Summary of Adverse Events

Event Category                        Treatment     Control       P-value
                                      (N=150)       (N=145)
                                      n (%)         n (%)
──────────────────────────────────────────────────────────────────────────
Any adverse event                     120 (80.0)    95 (65.5)     0.004

Treatment-related adverse events       85 (56.7)    42 (29.0)     <0.001

Serious adverse events                 12 (8.0)     8 (5.5)       0.412

Adverse events leading to              8 (5.3)      4 (2.8)       0.257
discontinuation

Deaths                                 0 (0.0)      1 (0.7)       0.492

Common adverse events (≥5% in any group)
  Nausea                              45 (30.0)     12 (8.3)      <0.001
  Diarrhea                            38 (25.3)     10 (6.9)      <0.001
  Headache                            22 (14.7)     18 (12.4)     0.568
  Hypoglycemia                        18 (12.0)     5 (3.4)       0.007
  Dizziness                           12 (8.0)      8 (5.5)       0.412
──────────────────────────────────────────────────────────────────────────
Adverse events coded using MedDRA version 24.0

Key elements:

Overall AE summary
Serious AEs highlighted
Deaths reported
Common AEs (typically ≥5% or ≥10% threshold)
MedDRA coding indicated

Laboratory Abnormalities Table

Shift tables showing changes from baseline:

Table 4. Laboratory Values Meeting Predefined Criteria for Abnormality

Laboratory Parameter                 Treatment      Control
                                     (N=150)        (N=145)
                                     n (%)          n (%)
──────────────────────────────────────────────────────────────────────────
ALT >3× ULN                          8 (5.3)        3 (2.1)
AST >3× ULN                          5 (3.3)        2 (1.4)
Total bilirubin >2× ULN              2 (1.3)        1 (0.7)
Creatinine >1.5× baseline            12 (8.0)       5 (3.4)
Hemoglobin <10 g/dL                  3 (2.0)        2 (1.4)
Platelets <100 × 10³/μL              1 (0.7)        0 (0.0)
──────────────────────────────────────────────────────────────────────────
ULN = upper limit of normal; ALT = alanine aminotransferase; 
AST = aspartate aminotransferase

Patient Disposition Table (CONSORT Format)

Table 5. Patient Disposition

Disposition                              Treatment     Control       Total
                                         (N=150)       (N=145)       (N=295)
────────────────────────────────────────────────────────────────────────────
Screened                                 -             -             425

Randomized                               150           145           295

Completed study                          135 (90.0)    130 (89.7)    265 (89.8)

Discontinued, n (%)                      15 (10.0)     15 (10.3)     30 (10.2)
  Adverse event                          8 (5.3)       4 (2.8)       12 (4.1)
  Lack of efficacy                       2 (1.3)       5 (3.4)       7 (2.4)
  Lost to follow-up                      3 (2.0)       4 (2.8)       7 (2.4)
  Withdrawal of consent                  2 (1.3)       2 (1.4)       4 (1.4)

Included in efficacy analysis
  ITT population                         150 (100)     145 (100)     295 (100)
  Per-protocol population                142 (94.7)    138 (95.2)    280 (94.9)

Included in safety analysis              150 (100)     145 (100)     295 (100)
────────────────────────────────────────────────────────────────────────────
ITT = intent-to-treat

Figures for Clinical Data

Figure Design Principles

General guidelines:

Clear, concise caption/legend below figure
Numbered sequentially (Figure 1, Figure 2, etc.)
Axis labels with units
Legible font size (minimum 8-10 point)
High resolution (300 dpi for print, 150 dpi for web)
Color-blind friendly palette
Black and white compatible (use different symbols/patterns)

Figure caption:

Describes what is shown
Explains symbols, error bars, statistical annotations
Defines abbreviations
Provides context for interpretation

CONSORT Flow Diagram

Purpose: Show patient flow through randomized trial

                    Assessed for eligibility (n=425)
                              │
        ┌─────────────────────┴─────────────────────┐
        │                                           │
    Excluded (n=130)                                │
    • Not meeting inclusion criteria (n=85)         │
    • Declined to participate (n=32)                │
    • Other reasons (n=13)                          │
                                                    │
                                           Randomized (n=295)
                                                    │
                    ┌───────────────────────────────┴───────────────────────────────┐
                    │                                                               │
        Allocated to Treatment (n=150)                             Allocated to Control (n=145)
        • Received allocated intervention (n=148)                  • Received allocated intervention (n=143)
        • Did not receive allocated intervention (n=2)             • Did not receive allocated intervention (n=2)
          Reasons: withdrew consent before treatment                Reasons: withdrew consent before treatment
                    │                                                               │
        ┌───────────┴────────────┐                                  ┌──────────────┴─────────────┐
        │                        │                                  │                            │
    Lost to follow-up (n=3)  Discontinued (n=12)              Lost to follow-up (n=4)     Discontinued (n=11)
                             • Adverse events (n=8)                                       • Adverse events (n=4)
                             • Lack of efficacy (n=2)                                     • Lack of efficacy (n=5)
                             • Withdrew consent (n=2)                                     • Withdrew consent (n=2)
                    │                                                               │
            Analyzed (n=150)                                               Analyzed (n=145)
            • ITT analysis (n=150)                                         • ITT analysis (n=145)
            • Per-protocol analysis (n=142)                                • Per-protocol analysis (n=138)
            • Excluded from analysis (n=0)                                 • Excluded from analysis (n=0)

Kaplan-Meier Survival Curve

Purpose: Show time-to-event data

Elements:

X-axis: Time (weeks, months, years)
Y-axis: Probability of event-free survival (0 to 1 or 0% to 100%)
Separate curves for each treatment group
Censored observations marked (often with vertical tick marks)
Number at risk table below graph
Median survival time indicated
Log-rank p-value
Hazard ratio with 95% CI

Caption example:

Figure 1. Kaplan-Meier Curves for Overall Survival

Kaplan-Meier estimates of overall survival in the treatment and control groups.
Tick marks indicate censored observations. Number at risk shown below graph.
Log-rank p<0.001. Median survival: Treatment 24.5 months (95% CI: 22.1-26.8),
Control 18.2 months (95% CI: 16.5-20.1). Hazard ratio 0.68 (95% CI: 0.55-0.84).

Forest Plot

Purpose: Display subgroup analyses or meta-analysis results

Elements:

Point estimates (squares or diamonds)
Size of symbol proportional to precision (inverse variance) or sample size
Horizontal lines showing 95% CI
Vertical line at null effect (HR=1.0, OR=1.0, or difference=0)
Subgroup labels on left
Effect size values on right
Overall estimate (if meta-analysis)
Heterogeneity statistics (I², p-value)

Caption example:

Figure 2. Forest Plot of Treatment Effect by Subgroup

Effect of treatment vs. control on primary endpoint across pre-specified subgroups.
Squares represent point estimates; horizontal lines represent 95% confidence intervals.
Square size is proportional to subgroup sample size. Overall effect shown as diamond.
p-value for interaction testing heterogeneity of treatment effect across subgroups.

Box Plot

Purpose: Show distribution of continuous variable

Elements:

Box: IQR (25th to 75th percentile)
Line in box: Median
Whiskers: Extend to most extreme data point within 1.5 × IQR
Outliers: Points beyond whiskers (often shown as circles)
X-axis: Groups or time points
Y-axis: Continuous variable with units

Scatter Plot with Regression

Purpose: Show relationship between two continuous variables

Elements:

X-axis: Independent variable
Y-axis: Dependent variable
Individual data points
Regression line (if appropriate)
Regression equation
R² value
P-value for slope
95% confidence interval for regression line (optional, shown as shaded area)

Spaghetti Plot

Purpose: Show individual trajectories over time

Elements:

X-axis: Time
Y-axis: Outcome variable
Individual patient lines (often semi-transparent)
Mean trajectory (bold line)
Separate colors for treatment groups

Bar Chart

Purpose: Compare proportions or means across groups

Elements:

Clear separation between bars
Error bars (SEM or 95% CI)
Y-axis starts at 0 (do not truncate for bar charts)
Group labels on X-axis
Value labels on Y-axis with units
Statistical significance indicated (p-values or asterisks)

Avoid:

3D bar charts (distort perception)
Excessive decoration
Truncated Y-axis for bars

Line Graph

Purpose: Show changes over time

Elements:

X-axis: Time (with consistent intervals)
Y-axis: Outcome variable
Separate lines for each group (different colors/patterns)
Data points marked (circles, squares, triangles)
Error bars at each time point (SE or 95% CI)
Legend identifying groups
Grid lines (optional, light gray)

Histogram

Purpose: Show distribution of continuous variable

Elements:

X-axis: Variable (divided into bins)
Y-axis: Frequency or density
Appropriate bin width (not too few, not too many)
Overlay normal distribution curve (if testing normality)

Special Considerations for Clinical Data

Presenting Proportions

Numerator and denominator:

Always provide both: 25/100 (25%)
Not just percentage (25%)

Percentages:

No decimal places if n<100
1 decimal place if n≥100
Never report >1 decimal place for percentages

Confidence intervals for proportions:

Wilson score interval or exact binomial (better than Wald for small samples)
Always report with percentage

Presenting Continuous Data

Measures of central tendency:

Mean for normally distributed data
Median for skewed data or ordinal data
Report both if distribution unclear

Measures of dispersion:

Standard deviation (SD): Describes variability in data
Standard error (SE): Describes precision of mean estimate
95% Confidence interval: Preferred for inferential statistics
Interquartile range (IQR): With median for skewed data
Range: Min to max

When to use each:

Descriptive statistics → Mean (SD) or Median (IQR)
Inferential statistics → Mean (95% CI) or Mean (SE)
Never use ± without specifying SD, SE, or CI

Presenting P-values

Reporting guidelines:

Report exact p-values to 2-3 decimal places (p=0.042)
For very small p-values, use p<0.001 (not p=0.000)
Do not report as "NS" or "p=NS"
For non-significant results, report exact p-value (p=0.18, not p>0.05)
Specify two-tailed unless pre-specified one-tailed
Correct for multiple comparisons when appropriate
Report significance threshold used (α=0.05 is standard)

Avoid:

p<0.05 (report exact value)
p=0.00 (impossible)
Multiple decimal places (p=0.04235891)

Statistical Significance Indicators

Options:

Report p-values in table
Use asterisks with legend:
- *p<0.05
- **p<0.01
- ***p<0.001
Use confidence intervals (preferred)

Confidence Intervals

Reporting:

95% CI is standard
Format: (lower limit, upper limit)
Or: lower limit to upper limit
Or: lower limit-upper limit

Interpretation:

If CI for difference excludes 0 → significant
If CI for ratio excludes 1 → significant
Width of CI indicates precision

Missing Data

Indicate clearly:

Footnote explaining missing data
State clearly if analysis is complete case
Describe imputation method if used
Report amount of missing data per variable

Decimal Places and Rounding

General rules:

Report to level of measurement precision
Consistent decimal places within table
Round p-values to 2-3 decimal places
Round percentages to 0-1 decimal place
Round means/medians to 1-2 decimal places
Include appropriate significant figures

Software for Creating Figures

Statistical software:

R (ggplot2) - highly customizable
GraphPad Prism - user-friendly for biomedical
SAS, Stata, SPSS - comprehensive statistical packages
Python (matplotlib, seaborn) - flexible and powerful

General graphics software:

Adobe Illustrator - professional publication-quality
Inkscape - free vector graphics editor
PowerPoint - basic graphs, easy to use
BioRender - biological schematics and figures

Color Schemes

Color-blind friendly palettes:

Avoid red-green combinations
Use blue-orange, blue-yellow
Include shape/pattern differences
Test figures in grayscale

Recommended palettes:

ColorBrewer (designed for data visualization)
Viridis (perceptually uniform)
IBM Color Blind Safe Palette

Image Quality Standards

Resolution:

300 dpi for print publication
150 dpi for web/screen
Vector graphics (PDF, SVG) preferred for graphs

File formats:

TIFF or EPS for print
PNG for web
PDF for vector graphics
JPEG acceptable for photographs (high quality)

Image editing:

No manipulation that alters data
Only acceptable adjustments: brightness, contrast, color balance applied to entire image
Document all adjustments
Provide original images if requested

This reference provides comprehensive guidance for presenting clinical data in tables and figures following best practices and publication standards. Use these guidelines to create clear, accurate, and professional data presentations.