Page 74 - When surgery alone won’t cut it - Valerie Maureen Monpellier

Chapter 4
Inclusion criteria
All 2,562 patients who had undergone a primary RYGB before 2014 were selected from the database. Patients were included when IWQOL-lite or RAND-36 results were available before surgery and at least one-time post-surgery.
Health-related Quality of Life
IWQOL-lite
The IWQOL-lite is a 31-item questionnaire which assesses the impact of weight on quality of life in five domains. This questionnaire has shown good validity and reliabil- ity in obese patients (test-rest reliability r=0.74-0.91; internal consistency, Cronbach’s alpha 0.85) and was used before in the bariatric population 5,14. In addition to a total score, there are scores on five scales: physical function, self-esteem, sexual life, pub- lic distress and work 15.
RAND-36
The RAND-36 is a general HRQoL questionnaire with 36 questions and 9 scales: emo- tional role functioning, social functioning, vitality, physical functioning, mental health, bodily pain, general health perceptions, health change and physical role functioning. From these scales two subtotals can be calculated: physical health summary (PHS) and mental health summary (MHS) 16. The RAND-36 has also been validated for the obese population (test-rest reliability r=0.94; internal consistency, Cronbach’s alpha 0.96) 16.
For both questionnaires a high score represents a higher HRQoL and scores range from 0-100. The smallest difference in score, which the patient perceives as benefi- cial, is the minimal clinically important difference (MCID). In previous research with bariatric patients the MCID threshold for RAND-36 was 5, for IWQOL-lite this thresh- old was 12 17.
Body weight and other parameters
Body weight was assessed at the same time points as HRQoL; height was assessed during preoperative screening. Weight loss was calculated and reported as stated in the most recent guidelines: Body Mass Index (BMI in kg/m2), BMI difference (ΔBMI) and percent total weight loss (%TWL) 5. The following parameters were also reg- istered: gender, age and comorbidities (diabetes mellitus, hypertension, obstructive sleep apnoea syndrome, hypercholesterolemia and osteoarthritis) at baseline.
Statistical analysis
Descriptive statistics summarized the patients’ characteristics. Differences from base- line to follow-up points in HRQoL were analyzed with repeated measures ANOVA. Dif-
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