Weight loss required by the severely obese to achieve clinically important differences in health-related quality of life: two-year prospective cohort study

Abstract

BackgroundGuidelines and experts describe 5% to 10% reductions in body weight as ‘clinically important’; however, it is not clear if 5% to 10% weight reductions correspond to clinically important improvements in health-related quality of life (HRQL). Our objective was to calculate the amount of weight loss required to attain established minimal clinically important differences (MCIDs) in HRQL, measured using three validated instruments.MethodsData from the Alberta Population-based Prospective Evaluation of Quality of Life Outcomes and Economic Impact of Bariatric Surgery (APPLES) study, a population-based, prospective Canadian cohort including 150 wait-listed, 200 medically managed and 150 surgically treated patients were examined. Two-year changes in weight and HRQL measures (Short-Form (SF)-12 physical (PCS; MCID = 5) and mental (MCS; MCID = 5) component summary score, EQ-5D Index (MCID = 0.03) and Visual Analog Scale (VAS; MCID = 10), Impact of Weight on Quality of Life (IWQOL)-Lite total score (MCID = 12)) were calculated. Separate multivariable linear regression models were constructed within medically and surgically treated patients to determine if weight changes achieved HRQL MCIDs. Pooled analysis in all 500 patients was performed to estimate the weight reductions required to achieve the pre-defined MCID for each HRQL instrument.ResultsMean age was 43.7 (SD 9.6) years, 88% were women, 92% were white, and mean initial body mass index was 47.9 (SD 8.1) kg/m2. In surgically treated patients (two-year weight loss = 16%), HRQL MCIDs were reached for all instruments except the SF-12 MCS. In medically managed patients (two-year weight loss = 3%), MCIDs were attained in the EQ-index but not the other instruments. In all patients, percent weight reductions to achieve MCIDs were: 23% (95% confidence interval (CI): 17.5, 32.5) for PCS, 25% (17.5, 40.2) for MCS, 9% (6.2, 15.0) for EQ-Index, 23% (17.3, 36.1) for EQ-VAS, and 17% (14.1, 20.4) for IWQOL-Lite total score.ConclusionsWeight reductions to achieve MCIDs for most HRQL instruments are markedly higher than the conventional threshold of 5% to 10%. Surgical, but not medical treatment, consistently led to clinically important improvements in HRQL over two years.Trial registrationClinicaltrials.gov NCT00850356.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-014-0175-5) contains supplementary material, which is available to authorized users.

Efficacy and Safety ofCissus quadrangularisL. in Clinical Use: A Systematic Review and Meta-analysis of Randomized Controlled Trials

“…In the present meta‐analysis, reduction of body weight by Cissus combination products was not clinically significant because minimal clinically important difference for weight loss was 5% reduction (Warkentin et al ). Whereas changes of lipid levels such as LDL, TG, and HDL by Cissus combination products were clinically significant because their changing ranged in the same values of current standard medications for dyslipidemia such as simvastatin, gemfibrozil, which changed lipid levels from 5 to 55% (NCEP III.…”

Bariatric and metabolic surgery: a shift in eligibility and success criteria

“…Importantly, weight reductions to achieve minimal clinically important differences for most HRQL instruments (such as the Impact of Weight on Quality of Life [IWQOL]-Lite survey consisting of 31 items describing five domains [physical function, self-esteem, sexual life, public distress and work]) after surgery are markedly higher (the IWQOL-Lite total score was reached for 49% of medically treated patients and 76% of surgically treated patients)] than the conventionally considered threshold of 5-10%. 78 Thus, surgical, but not medical, treatment consistently led to clinically important improvements in HRQL over 2 years. 78 As expected, bariatric surgery exerted profound effects on HRQL with net gains compared with baseline being observed after 10 years.…”

“…78 Thus, surgical, but not medical, treatment consistently led to clinically important improvements in HRQL over 2 years. 78 As expected, bariatric surgery exerted profound effects on HRQL with net gains compared with baseline being observed after 10 years. 79 This finding alone justifies surgical treatment of patients with severe obesity.…”

Health Benefits of Long-Term Weight-Loss Maintenance

“…A recent paper by Warkentin et al (229) challenged the common assumption that a 5% to 10% weight loss can produce a relevant change in QOL. Using data from a population-based prospective Canadian cohort, the authors estimated that to achieve a clinically relevant change in QOL, the minimal body weight reduction required ranged from 17% to 25%, depending on the scale used to assess QOL (229).…”