Use of SPSS in Medical Science: Complete Beginner's Guide 2026

SPSS (Statistical Package for the Social Sciences), now marketed as IBM SPSS Statistics, is the most widely used statistical software in Indian medical research. Its menu-driven interface makes it accessible to researchers without programming skills. This guide covers everything you need to know to use SPSS effectively for your MD, MS, DNB, or MSc Nursing thesis.

Why SPSS for Medical Research?

• Menu-driven interface — no coding required for most analyses
• Point-and-click access to a comprehensive range of statistical tests
• Most widely accepted by Indian universities and ethics committees
• Excellent output format suitable for direct thesis tables
• Wide availability in Indian medical colleges (institutional licenses)
• Handles large datasets easily (thousands of patients, hundreds of variables)
• Widely cited in peer-reviewed medical journals globally

Data Entry in SPSS

SPSS has two views: Data View (where you enter data) and Variable View (where you define variables).

• Variable View setup: Name, Type (Numeric/String), Width, Decimals, Label, Values, Missing
• Assign numeric codes to categorical variables (e.g., Male=1, Female=2)
• Use "Values" column to label codes (so output shows "Male"/"Female" not 1/2)
• Designate missing values (e.g., 99 or 999) in the "Missing" column
• Import from Excel: File → Import Data → Excel
• Always run frequency checks after data entry to identify entry errors
• Back up your .sav file regularly

Descriptive Statistics in SPSS

• Frequencies: Analyze → Descriptive Statistics → Frequencies (for categorical variables)
• Descriptives: Analyze → Descriptive Statistics → Descriptives (for continuous variables — mean, SD, min, max)
• Explore: Analyze → Descriptive Statistics → Explore (includes normality tests: Kolmogorov-Smirnov, Shapiro-Wilk)
• Test normality before choosing parametric vs non-parametric tests
• Shapiro-Wilk preferred for n < 50; K-S test for larger samples
• If p > 0.05 in normality test: data is normally distributed → use parametric tests
• If p < 0.05 in normality test: data is not normal → use non-parametric tests

Hypothesis Testing in SPSS

• Independent samples t-test: Analyze → Compare Means → Independent Samples T Test (compare means of 2 groups)
• Paired t-test: Analyze → Compare Means → Paired Samples T Test (before-after data)
• One-way ANOVA: Analyze → Compare Means → One-Way ANOVA (3+ groups, continuous outcome)
• Chi-square test: Analyze → Descriptive Statistics → Crosstabs → Statistics → Chi-square (categorical variables)
• Mann-Whitney U: Analyze → Nonparametric Tests → Legacy → 2 Independent Samples (non-normal data, 2 groups)
• Kruskal-Wallis: Nonparametric alternative to one-way ANOVA (3+ groups, non-normal data)
• Wilcoxon signed-rank test: Nonparametric alternative to paired t-test

Correlation & Regression in SPSS

• Pearson correlation: Analyze → Correlate → Bivariate (for normally distributed continuous variables)
• Spearman correlation: Same path, check "Spearman" (for non-normal or ordinal data)
• Simple linear regression: Analyze → Regression → Linear (one predictor, continuous outcome)
• Multiple linear regression: Same, add multiple predictors (control for confounders)
• Binary logistic regression: Analyze → Regression → Binary Logistic (categorical outcome: Yes/No)
• Report: β coefficient, OR (for logistic), 95% CI, p-value for each predictor
• Check model assumptions: residual normality, multicollinearity (VIF < 10)

Survival Analysis in SPSS

• Kaplan-Meier survival curves: Analyze → Survival → Kaplan-Meier
• Used for time-to-event data (time to death, recurrence, discharge)
• Log-rank test compares survival curves between groups
• Cox regression: Analyze → Survival → Cox Regression (adjusts for confounders)
• Report: median survival time, hazard ratio (HR) with 95% CI, log-rank p-value
• Common in oncology, cardiology, and infectious disease research

SPSS Alternatives

• R (free): Most powerful, widely published, requires coding knowledge
• Stata (paid): Popular in epidemiology, excellent for survival and panel data
• SAS (paid): Gold standard for clinical trials and FDA submissions
• GraphPad Prism (paid): Excellent for laboratory and biological data
• Jamovi (free): User-friendly, R-based, good SPSS alternative
• JASP (free): Bayesian statistics, clean interface
• For Indian PG thesis: SPSS remains the most widely accepted and available software