Reliability and validity of measuring scale for post-surgical complication in third molar surger

Objectives: The aim of this study was to evaluate the reliability and validity of a scale designed to measure post-surgical complication (PSC) in third molar surgery (TMS).
Methods: A scale validation study was designed. In a first stage 62 patients (average age 20.5±6.6 years; 58.1% women) was involved undergoing a TMS in three hospitals in Chile between 2012 and 2013. During the postoperative examinations, one maxillofacial surgeons and one surgical trainee diagnosed the presence and degree of severity of the complications in applying scale study. In the second stage, a confirmatory factor analysis was performed to obtain convergent and discriminant validity, internal consistency, interobserver reliability and discrimination score of severity of PSC. Data with descriptive and inferential statistics of interdependence (structural equation models) and dependence data (CART: Classification and Regression Trees) were applied
Results: From the total patients, 104 third molars were extracted and 14.5% of post-surgical sequellae after TMS were observed. The factor analysis instrument defined two components: “secondary complication” (swelling, edema and pain) and “infection” (abscess and alveolitis) with a Cronbach’s alpha of 0.79 and 0.71 respectively. A scale with interobserver reliability of 87.7 % was recorded. The instrument discriminated three ranges: without complication or mild (4-13 points); moderate complication (14-18 points) and severe complication (over 19 points).
Conclusions: This study presents a reliability and validity scale for the registration and classification of post-surgical complication in TMS called “Surgical complication Assessment Scale in Third Molar Surgery (SCATM)”.