Validation

Validation Reports

Every nQuery Advisor® sample size table, distribution function table, standard deviation table, and table-specific side table has been tested for computational accuracy across table-specific ranges of parameters, and has been tested for full functionality of editing options and menu items (side tables, plots, statements) for one or more table-specific parameter sets. Methods for testing are described in Validation Procedures.

The following list details individual validation reports for the sample size and distribution function tables. nQuery Advisor® sample size tables are indexed by goals (means, proportions, survival, agreement and regression), by number of groups (one, two, or more than two), by type of analysis (test, confidence interval, equivalence test), and by equal vs unequal n.

Distribution functions

• z (Normal/Gaussian)
• t distribution
• t distribution (non-central)
• Chi-square distribution

Means

Tests

One group

• MOT0 One group t-test
• MOT1 Paired t test for difference in means

Two group

• MTT0 Two group t-test (equal n’s)
• MTT0U Two group t-test (unequal n’s)
• MTT4 t-test (ANOVA) for difference of means in 2×2 crossover design

G groups

• MGT1 Single one-way between means contrast (equal n’s)
• MGT1U Single one-way between means contrast (unequal n’s)

Confidence interval

Two group

• MTC0 Confidence interval for difference in means (large equal n’s)
• MTC1 Confidence interval for difference in means (coverage probability)

Equivalence

Two group

• MTE0 Two group t-test for equivalence in means (equal n’s)
• MTE0U Two group t-test for equivalence in means (unequal n’s)
• MTE1tg Two group t-tests (TOST) of equivalence in means (equal n’s)
• MTE1co t-tests (TOST) of equivalence in means for crossover designs (equal n’s)

Proportions

Tests

One group

• POT0x Exact test for single proportion

Two group

• PTT0 Two group Chi-square test of equal proportions (equal n’s)
• PTT0U Two group Chi-square test of equal proportions (unequal n’s)
• PTT1 Two group continuity corrected Chi-square test of equal proportions (equal n’s)
• PTT1U Two group continuity corrected Chi-square test of proportions (unequal n’s)
• PTT3 Two group Chi-square test comparing proportions in C categories (equal n’s)

Confidence interval

Two group

• PTC3 Confidence interval for relative risk (ratio of proportions)

Equivalence

Two group

• PTE0 Two group test of equivalence in proportions (equal n’s)
• PTE0U Two group test of equivalence in proportions (unequal n’s)

Survival

Tests

Two group

• STT0 Log rank test of survival in two groups (equal n’s)
• STT2 Two group test of equal exponential survival (n large), exponential dropout (equal n’s)

Equivalence

Two-group

• STE0 Non-inferiority test for two exponential survival curves

Agreement

Tests

One-group

• AOT0 Agreement between two dichotomous ratings (intraclass kappa)
• AOT2 Large sample test that Lin’s concordance coefficient = K0

Confidence interval

One-group

• AOC2 One-sample large sample confidence interval for concordance coefficient
• AOC3 Confidence interval for intraclass correlation for k measurements

Regression

Tests

One-group

• ROT0 Logistic regression for one normally distributed covariate