Psychometric evaluation of Patient Scar Assessment Questionnaire following thyroid and parathyroid surgery
Konstantinos P Economopoulos1, Athanasios Petralias, Eleni Linos
1Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA. economopoulos@sni.gr
Background:
The Patient Scar Assessment Questionnaire (PSAQ) was constructed to evaluate the effect of any surgical therapy with a linear scar. This study aims to demonstrate reliability and validity of Appearance and Consciousness subscales of PSAQ in patients who underwent thyroidectomy or parathyroidectomy.
Methods:
Patients who underwent a thyroidectomy or parathyroidectomy between 2000 and 2010 were administered the aforementioned subscales of the PSAQ. Each subscale was separately evaluated for its psychometric performance according to established criteria. Acceptability, reliability, and internal validity analysis were conducted.
Results:
There were 696 patients (mean age=51.6 years) who participated in this study. Cronbach's alpha acceptable levels were demonstrated for the Appearance (α=0.79) and Consciousness (α=0.85) subscales. Reliability was also supported for the Appearance (Intraclass Correlation Coefficient [ICC]=0.79) and Consciousness subscales (ICC=0.81) by performing test-retest reliability analysis. Individual subscale items' correlations with all subscale scores were acceptable for the Appearance (0.31 to 0.78) and Consciousness (0.23 to 0.81) subscales. Internal validity was supported by evaluating correlations between the global assessment item of each subscale and both summary subscale scores (Appearance: 0.42 to 0.72, Consciousness: 0.66 to 0.67).
Conclusions:
The Appearance and Consciousness subscales of the PSAQ are both reliable and valid for the assessment of a linear scar following thyroid or parathyroid surgery, independent of the minimally invasive approach being used.