Accuracy Assessment Criteria
Our comprehensive criteria for evaluating the accuracy of DEXA scan results, based on extensive research and clinical guidelines.
Accuracy Assessment Framework
Our framework evaluates four key categories of potential errors in DEXA scans
Assessment Categories
Instrumental Errors (25%)
Evaluates calibration, measurement variability, and hardware artifacts that can affect scan accuracy.
Patient-Related Errors (30%)
Assesses artifacts, BMI effects, contrast studies, and degenerative changes that can impact results.
Technologist-Related Errors (25%)
Examines patient positioning, ROI placement, and data analysis techniques used during the scan.
Reporting Errors (20%)
Evaluates T-score interpretation, demographic data accuracy, and spine vs. hip discordance.
Detailed Criteria
Specific criteria used to evaluate each category of potential errors
Instrumental Errors (25% of total weight)
| Criterion | Description | Threshold | Weight |
|---|---|---|---|
| Calibration | Verification of daily phantom calibration | Performed/Not performed | 10% |
| Measurement Variability | Coefficient of variation (CV) for repeated measurements | CV ≤ 1.5% for spine, ≤ 2.0% for femoral neck, ≤ 1.5% for total hip | 10% |
| Hardware Artifacts | Presence of detector streaks, calibration drift | Absent/Present | 5% |
Patient-Related Errors (30% of total weight)
| Criterion | Description | Threshold | Weight |
|---|---|---|---|
| Artifacts | Presence of metal implants, surgical hardware, calcifications | Absent/Present | 10% |
| Body Mass Index (BMI) | Extreme BMI values affecting measurements | 18.5 ≤ BMI ≤ 35 | 5% |
| Recent Contrast Studies | Effect of contrast agents on measurements | None within past 14 days | 5% |
| Degenerative Changes | Presence of osteophytes, osteoarthritis, vascular calcifications | Absent/Present | 10% |
Technologist-Related Errors (25% of total weight)
| Criterion | Description | Threshold | Weight |
|---|---|---|---|
| Patient Positioning | Proper alignment and femur rotation | Correct/Incorrect | 10% |
| ROI Placement | Correct selection and labeling of region of interest | Correct/Incorrect | 10% |
| Data Analysis | Correct application of analysis protocols | Correct/Incorrect | 5% |
Reporting Errors (20% of total weight)
| Criterion | Description | Threshold | Weight |
|---|---|---|---|
| T-score Interpretation | Correct application of WHO diagnostic criteria | Correct/Incorrect | 5% |
| Demographic Data | Accuracy of age, sex, ethnicity input | Correct/Incorrect | 5% |
| Spine vs. Hip Discordance | Difference between spine and hip T-scores | Difference ≤ 1.0 SD | 10% |
Accuracy Classification
How we classify the overall accuracy of DEXA scan results
High Accuracy
90-100%
Minimal errors with negligible impact on diagnosis and treatment decisions.
Medium Accuracy
75-89%
Some errors present that may affect interpretation but unlikely to significantly alter diagnosis.
Low Accuracy
Below 75%
Significant errors that could potentially affect diagnosis and treatment decisions.