The modified Memorial Symptom Assessment Scale Short Form: a modified response format and rational scoring rules.

Purpose: The Memorial Symptom Assessment Scale Short Form (MSAS-SF) is a widely used symptom assessment instrument. Patients who self-complete the MSAS-SF have difficulty following the two-part response format, resulting in incorrectly completed responses. We describe modifications to the response format to improve useability, and rational scoring rules for incorrectly completed items.
Methods: The modified MSAS-SF was completed by 311 women in our Peer and Nurse support Trial to Assist women in Gynaecological Oncology; the PeNTAGOn study. Descriptive statistics were used to summarise completion of the modified MSAS-SF, and provide symptom statistics before and after applying the rational scoring rules. Spearman's correlations with the Functional Assessment for Cancer Therapy-General (FACT-G) and Hospital Anxiety and Depression Scale (HADS) were assessed.
Results: Correct completion of the modified MSAS-SF items ranged from 91.5 to 98.7%. The rational scoring rules increased the percentage of useable responses on average 4% across all symptoms. MSAS-SF item statistics were similar with and without the scoring rules. The pattern of correlations with FACT-G and HADS was compatible with prior research.
Conclusion: The modified MSAS-SF was useable for self-completion and responses demonstrated validity. The rational scoring rules can minimise loss of data from incorrectly completed responses. Further investigation is recommended.