The Southampton Dupuytren's scoring scheme

Aim

To construct and validate a simple patient related outcome measure scheme to quantify the disability caused by Dupuytren's Disease thus enabling prioritisation of treatment, allow reliable audit of surgical outcome and support future research.

Methods

The Southampton Dupuytren's Scoring System (SDSS) was developed in a staged fashion according to the recommendations of Derby Outcomes Conference.

1. item generation from questionnaire filled in by 20 patients;

2. item reduction to create a 20-question proforma;

3. Internal consistency (Cronbach's alpha)

4. Test-retest (3 week interval testing on 61 patients)

5. Field management was used to assess the user friendliness of the scoring system.

6. Sensitivity to change Standardised response mean

7. Construct validity: ability of the SDSS to measure what it is supposed to measure. comparing SDSS with QuickDASH (Disability of Arm, Shoulder and Hand)

Results

Test-retest reliability

The test re-test correlation coefficient was 0.79 between SDSS scores at a three-week interval (high reliability).

Field-testing

The SDSS ratings were found to be higher than the QDASH ratings evaluated by the patients who answered both questionnaires.

Sensitivity to change

Standardised response mean was more sensitive for SDSS compared to QuickDASH (−1.76 vs −1.19 p>0.05)

Construct Validity

To assess if the SDSS is measuring what is supposed to measure, we compared the SDSS with QuickDASH. A high significant correlation (Pearson correlation-0.598) was found between the two scoring-systems.

Conclusions

SDSS is a suitable disease-specific patient related outcome measure for DD. It has good internal consistency and is performs better than QuickDASH in terms of test-retest reliability and sensitivity to change. SDSS shows better field-testing attributes suggesting that it is a relatively more patient and practitioner friendly scoring-system. We propose the SDSS is a useful patient related outcome measure for DD.