Evaluating the 8‐item overactive bladder questionnaire (OAB‐v8) using item response theory
Bibliographic record
Abstract
AIMS: The OAB-v8 is a patient-reported outcome questionnaire used to screen for overactive bladder and measure symptom bother. This study uses modern validation methods to assess the item and test characteristics of the OAB-v8, and determine whether it should be scored differently for men and women. METHODS: A secondary analysis of data from patients with lower urinary tract symptoms prospectively recruited from a urology clinic in Calgary, Canada. Item-response theory (IRT) was used to evaluate the dimensionality, reliability, and validity of the OAB-v8, and differential functioning analysis (DIF) was used to determine whether the OAB-v8 should be scored differently for men and women. RESULTS: A total of 1128 patients were included for analysis, of which 28% were female. Mean OAB-v8 scores indicated meaningful levels of symptom bother, and women scored 2 points higher, on average, than men (P = 0.005). Reliability was high (Cronbach's alpha = 0.901) for a wide range of patients (between -2 and 2.5 standard deviations of the mean). Samejima's graded response model best fit the data, and the scale demonstrated essential unidimensionality. Items #5 and #6 were excessively correlated. There was no evidence of differential functioning. CONCLUSIONS: OAB-v8 demonstrated high reliability and would be appropriate for a wide range of patients. Items #5 and #6 may need to be re-worded. The OAB-v8 should not be scored differently for men and women, although women do appear to experience higher average levels of symptom bother from OAB than men.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".