Quality-of-life assessment of morbidly obese patients who have undergone a Lap-Band operation: 2-year follow-up study. Is the MOS SF-36 a useful instrument to measure quality of life in morbidly obese patients?

BACKGROUND

Quality of life (QoL) was tested in a 2-year postoperative study using the Medical Outcome Study Short Form 36 (MOS SF-36) to assess preoperative and 1 and 2 year postoperative QoL among one group of female patients (group 1, n = 42) and a 2 year postoperative QoL study in a second group of female patients (group 2, n = 9) who underwent a stomach reduction operation involving open surgical placement of a Lap-Band during the year 1997.

METHODS

The QoL of 42 patients (group 1) was assessed at most 20 hours before surgery and 1 and 2 years (12 and 24 months) postoperatively using a randomized pre-test/post-test design. The QoL of 9 patients (group 2) was assessed 2 years (24 months) postoperatively using a randomized post-test design only. The results were compared with the standardized Dutch norm datascale. Statistical data were analyzed with SPSS versions 10.0.

RESULTS

The placement of a Lap-Band in group 1 resulted in a significant reduction in Body Mass Index (BMI) in the first and second-year follow-up. Mean BMI declined significantly from 40.7 kg/m2 preoperatively to 33.1 kg/m2 at the 1-year follow-up, to 31.3 kg/m2 at 2-year follow-up. In group 2 BMI also declined significantly from 43.0 kg/m2 preoperatively to 34.2 kg/m2 at 1-year follow-up to 32.1 kg/m2 at the 2-year follow-up. Compared to the MOS SF-36 standardized Dutch norm data, a significant improvement in the QoL was seen on the effect variable bodily pain, mental health and general health perceptions in group 1. Although the bodily pain, general health and mental health perceptions increased significantly 2 years postoperatively (group 1) compared with the Dutch standardized norm data, the preoperative general health and mental health perceptions of morbidly obese patients were, like all other preoperative effect variables, not significantly different from the scores on the Dutch standardized norm scale.

CONCLUSION

Although other authors found that QoL improves after surgical-induced weight loss, showing significant improvements on patients' perception of their health status, these findings were not confirmed in the present study. The findings show only a significant difference in bodily pain, general health and mental health perception before and after surgical intervention and preoperatively in group 1 compared to the Dutch standardized norm data. Because of small sample size (n = 9), no significant results were found in group 2 compared to the Dutch Standardized norm data. Based on earlier and present findings, further study is recommended to ascertain whether the MOS SF-36 is valid in morbidly obese patients and whether the response set has an influence on QoL studies of these patients.