This is the first validation study of a psychometric tool to assess the use of Brazilian-Portuguese MA-II among patients with severe obesity. In our study, 92.4% of the patients reliably reported fair to very good HRQoL, and only 7.6% reported poor or very poor HRQoL. The magnitude of BMI was associated with poor HRQoL, where physical exercise (Q2) and job performance (Q4) impacted the HRQoL. The constructs covered by the MA-II were associated with depressive symptoms and global functioning, both assessed by clinicians. The validation of a brief instrument for the population with obesity contributes to monitoring the HRQoL of bariatric patients across all stages of bariatric procedure. Regardless of the individuals’ education, patients with severe obesity present several limitations and difficulties that require further cost-effective evaluation.
Globally, MA-II is an easy HRQoL tool to understand and apply [27]. In most non-English adaptations, the internal consistency of the questionnaire was good or satisfactory [13, 28, 9, 10, 11, 12, 29], ranging from 0.72 to 0.88. Therefore, our coefficient of internal consistency of 0.70 was acceptable when compared with different linguistic versions of the MA-II.
On the other hand, the multidimensional concept of HRQoL [6] might not be fully captured by the six-item MA-II [12]. Some item wordings and image cues might require adjustment as we remarked [28, 29]. Regarding the capacity of the MA-II to capture HRQoL, the magnitude of the ceiling effect of the total score in our study is in line with the previous estimate of 2% in the Portuguese version [12]. In other words, the ceiling effect is a psychometric limitation that occurs when the highest possible score on a test is reached, disturbing its discriminant capacity. This finding is in contrast with the common expectation of poor HRQoL during the pre-surgical period [30]. Therefore, further investigations should clarify the applicability of MA-II in different language versions and contexts.
Patients with obesity that do not enjoy physical exercise tend to be less active [31]. In addition, some patients present mobility problems or fear of injury, causing hardships in engaging in physical exercise [32]. These factors can jointly induce weight gain. The excess weight jeopardizes the HRQoL [5]. Several findings support our results [12, 33], where BMI predicted poor HRQoL.
The correlation between capability for work and BMI can be supported through improvements in labor productivity and the functioning of patients after bariatric surgery [34]. Patients with obesity and associated medical problems tend to take off work due to health issues. Weight loss and the recovery of associated medical problems could improve efficiency and satisfaction with work. Most importantly, both the domain of physical activities and work satisfaction were conspicuously identified by the MA-II.
Depressive symptoms are disabling, so it should be one of the main factors considered in HRQoL [35, 36]. In the first validation study of the MA-II [14], the total score of the questionnaire was correlated with the widely used Beck Depression Inventory-II (BDI-II). In our study, we have chosen an observer-based interview - the MADRS - to rate the severity of depressive symptoms among bariatric patients [37]. Although the presence of depressive symptoms, per si, should not be equated to poor mental health, previous studies have compared the MA-II with different instruments to evaluate mental health. For example, the SF-36 and the IWQoL-Lite are common tools for evaluating the mental dimension [7, 9, 10, 12], and there is a consistent association between the MA-II and mental health. In short, the total score of the MA-II pointed out that the higher the score, the fewer depressive symptoms.
The comparison between standard measures of the functional dimension of HRQoL in a bariatric context is generally made through scales like SF-36 and WHODAS [2]. Most of the assessments evaluate how psychopathological symptoms or medical illnesses affect the patient's day-to-day life, as far as patients without obesity present a good HRQoL and functionality [25, 26]. In the present study, we used an observed-rated GAF to evaluate patients’ functionality [19, 38, 39]. While our resultsdid not allow comparing functionality measured with SF-36 and WHODAS, our estimates indicated that GAF-rated functionality was substantially associated with the MA-II.
A limitation of the present study is the sampling bias. Our sample was composed of patients on a waiting list for bariatric surgery from a single institution. The patients that participated in this study may have lower HRQoL compared with non-bariatric patients with obesity.