PurposeQuality of life (QOL) is an important concept in the field of health and medicine. QOL is a complex concept that is interpreted and defined differently within and between disciplines, including the fields of health and medicine. The aims of this study were to systematically review the literature on QOL in medicine and health research and to describe the country of origin, target groups, instruments, design, and conceptual issues.MethodsA systematic review was conducted to identify research studies on QOL and health-related quality of life (HRQOL). The databases Scopus, which includes Embase and MEDLINE, CINAHL, and PsycINFO were searched for articles published during one random week in November 2016. The ten predefined criteria of Gill and Feinstein were used to evaluate the conceptual and methodological rigor.ResultsQOL research is international and involves a variety of target groups, research designs, and QOL measures. According to the criteria of Gill and Feinstein, the results show that only 13% provided a definition of QOL, 6% distinguished QOL from HRQOL. The most frequently fulfilled criteria were: (i) stating the domains of QOL to be measured; (ii) giving a reason for choosing the instruments used; and (iii) aggregating the results from multiple items.ConclusionQOL is an important endpoint in medical and health research, and QOL research involves a variety of patient groups and different research designs. Based on the current evaluation of the methodological and conceptual clarity of QOL research, we conclude that the majority QOL studies in health and medicine have conceptual and methodological challenges.Electronic supplementary materialThe online version of this article (doi:10.1007/s11136-019-02214-9) contains supplementary material, which is available to authorized users.

SummaryThis is the first systematic review of reviews to assess the effect of obesity and weight loss on health‐related quality of life (HRQoL). We identified 12 meta‐analyses/systematic reviews published between January 2001 and July 2016. They addressed the following themes: (i) the relationship between weight/body mass index and HRQoL (baseline/pre‐intervention; n = 2). (ii) HRQoL after weight loss (varied interventions and/or study design; n = 2). (iii) HRQoL after weight loss (randomized controlled trials only; n = 2). (iv) HRQoL after bariatric surgery (n = 6). We found that in all populations, obesity was associated with significantly lower generic and obesity‐specific HRQoL. The relationship between weight loss and improved HRQoL was consistently demonstrated after bariatric surgery, perhaps due to a greater than average weight loss compared with other treatments. Improved HRQoL was evident after non‐surgical weight loss, but was not consistently demonstrated, even in randomized controlled trials. This inconsistency may be attributed to variation in quality of reporting, assessment measures, study populations and weight‐loss interventions. We recommend longer‐term studies, using both generic and obesity‐specific measures, which go beyond HRQoL in isolation to exploring mediators of HRQoL changes and interactions with other variables, such as comorbidities, fitness level and body image.

This large, rigorously conducted cluster RCT in 10-year-old children supports the notion that there is still inadequate evidence to conclude that increased physical activity in school enhances academic achievement in all children. Still, combining physical activity and learning seems a viable model to stimulate learning in those academically weakest schoolchildren.

Impaired health-related quality of life (HRQoL) is common in bariatric surgery candidates and is often one of the motivating factors for seeking bariatric surgery. Although many studies have reported changes in HRQoL after bariatric surgery, few are long-term prospective studies and no systematic review has been conducted. A systematic database search identified studies reporting HRQoL preoperatively and ≥ 5 years after bariatric surgery. Change in HRQoL over time was the outcome variable, divided into primary and secondary outcomes. Seven prospective cohort studies met the inclusion criteria. Eight HRQoL measures and six surgical methods were identified. Longterm follow-up time ranged from 5-10 years, sample sizes from 44 to 655 patients, and follow-up rates from 61 to 92%. None of the seven studies were randomized controlled trails and only two studies used control groups. Six out of seven studies showed statistically significant improvements in all of the primary outcomes, while one study showed statistically significant improvements in one of two primary outcomes. Of the statistically significant HRQoL improvements, 92 percent were clinically meaningful. Peak improvements in primary HRQoL outcomes were typically observed during the first years of follow-up, followed by a gradual decline that seemed to stabilize five years postoperatively. Long-term HRQoL scores typically remained improved relative to preoperative scores but were somewhat below population norm scores. In conclusion, while bariatric surgery candidates reported impaired HRQoL pre-surgically, their HRQoL improved considerably after bariatric surgery and much of the initial HRQoL improvements were maintained over the long term.

Our principal finding is that irritability, agitation, sleep disturbances, anxiety, apathy, and delusion seem to exert the most impact on caregiver burden. Heterogeneity in the measures and statistical analyses used, however, makes it difficult to make conclusive interpretations. Future research in this field would benefit from standardization of the scientific methodology in use. Copyright © 2017 John Wiley & Sons, Ltd.