The Multi-dimensional Assessment of Suicide Risk in Chronic illness-20 (MASC-20): Development and validation

Background: We developed and tested the psychometric properties of the Multi-dimensional assessment of suicide risk in chronic illness-20 (MASC-20), which assess suicidal behavior (SB), and its associated distress in chronic physical illness (CPI).

Methods: Items were developed by incorporating inputs from patient interviews, a review of existing instruments, and expert consultations. Pilot testing with 109 patients and field testing with 367 patients with renal, cardiovascular, and cerebrovascular diseases were conducted. We analyzed Time (T) 1 data to select items and T2 data to examine psychometric properties.

Results: Forty preliminary items were selected through pilot testing; 20 were finalized from field testing. Optimal internal consistency (α = 0.94) and test-retest reliability (Intra class correlation coefficient = 0.92) of the MASC-20 supported reliability. Good fit of the four-factor model (physical distress, psychological distress, social distress, and SB) from exploratory structural equation modeling demonstrated factorial validity. Its correlations with MINI suicidality (r = 0.59) and the Schedule of Attitudes Toward Hastened Death-abbreviated scores (r = 0.62) indicated convergent validity. Higher MASC-20 scores in patients with clinical levels of depression and anxiety and low health status demonstrated known-group validity. The MASC-20 distress score predicted SB beyond known SB risk factors, supporting incremental validity. A cutoff score of 16 was optimal for identifying suicide risk. The area under the curve was within a moderately accurate range. The sum of sensitivity and specificity (1.66) indicated diagnostic utility.

Limitations: MASC-20's applicability to other patient populations and its sensitivity to change requires testing.

Conclusions: The MASC-20 appears to be a reliable and valid tool for assessing SB in CPI.