Objective: Often the primary reason for doing craniofacial treatments is to improve the patient's quality of life (QoL). However, little is known about the QoL in repaired cleft lip and palate (CLP) patients. As the first study in Malaysia, assessing the reliability and validity of CLP QoL instrument before it is used in the actual study is very important. It is to ensure that the questionnaire is measuring what it is suppose to measure in a reproducible and consistent manner. This study was conducted to assess the reliability of CLP QoL questionnaire in relation to five domains: general, physical, social, psychological and satisfaction with daily activities. Methods: A QoL questionnaire was first developed and customized for CLP patients from SF 36 and WHOQoL, 2 well accepted general quality of life questionnaire. A workshop involving expertise in relevant fields was conducted to validate the content. The final questionnaire was of total 56 items with 36 items distributed in four health related domains: general, physical, social and psychological health while the remaining 20 items were in satisfaction with daily activities domain. Item analysis was performed after questionnaire administered to 120 repaired CLP participants.
Results: Based on the item analysis, a total of final 46 items were selected of which five, nine, four, ten and 18 items were distributed in general, physical, social, psychological and satisfaction with daily activities domains, respectively. The internal consistency reliability which represented by cronbach alpha were 0.70 (general), 0.83 (physical), 0.86 (social), 0.80 (psychological) and 0.94 (satisfaction with daily activities) with the total item correlation ranges from 0.40 – 0.78. Conclusion: From the item analysis, it suggests that the internal consistency reliability of CLP QoL questionnaire in relation to five QoL domains was fairly good.