| 1. |
- Sun, Sun, et al.
(författare)
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Mapping the obesity problems scale to the SF-6D : results based on the Scandinavian Obesity Surgery Registry (SOReg)
- 2023
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Ingår i: European Journal of Health Economics. - : Springer. - 1618-7598 .- 1618-7601. ; 24:2, s. 279-292
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obesity Problem Scale (OP) is a widely applied instrument for obesity, however currently calculation of health utility based on OP is not feasible as it is not a preference-based measure. Using data from the Scandinavian Obesity Surgery Registry (SOReg), we sought to develop a mapping algorithm to estimate SF-6D utility from OP. Furthermore, to test whether the mapping algorithm is robust to the effect of surgery.METHOD: The source data SOReg (n = 36 706) contains both OP and SF-36, collected at pre-surgery and at 1, 2 and 5 years post-surgery. The Ordinary Least Square (OLS), beta-regression and Tobit regression were used to predict the SF-6D utility for different time points respectively. Besides the main effect model, different combinations of patient characteristics (age, sex, Body Mass Index, obesity-related comorbidities) were tested. Both internal validation (split-sample validation) and validation with testing the mapping algorithm on a dataset from other time points were carried out. A multi-stage model selection process was used, accessing model consistency, parsimony, goodness-of-fit and predictive accuracy. Models with the best performance were selected as the final mapping algorithms.RESULTS: The final mapping algorithms were based on OP summary score using OLS models, for pre- and post-surgery respectively. Mapping algorithms with different combinations of patients' characteristics were presented, to satisfy the user with a different need.CONCLUSION: This study makes available algorithms enabling crosswalk from the Obesity Problem Scale to the SF-6D utility. Different mapping algorithms are recommended for the mapping of pre- and post-operative data.
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| 2. |
- Sun, Sun, et al.
(författare)
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Prediction of quality-adjusted life years (QALYs) after bariatric surgery using regularized linear regression models : results from a Swedish nationwide quality register
- 2023
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Ingår i: Obesity Surgery. - : Springer. - 0960-8923 .- 1708-0428. ; 33:8, s. 2452-2462
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate whether the quality-adjusted life years (QALYs) of the patients who underwent bariatric surgery could be predicted using their baseline information.MATERIALS AND METHODS: All patients who received bariatric surgery in Sweden between January 1, 2011 and March 31, 2019 were obtained from the Scandinavian Obesity Surgery Registry (SOReg). Baseline information included patients' sociodemographic characteristics, details regarding the procedure, and postsurgical conditions. QALYs were assessed by the SF-6D at follow-up years 1 and 2. The general and regularized linear regression models were used to predict postoperative QALYs.RESULTS: All regression models demonstrated satisfactory and comparable performance in predicting QALYs at follow-up year 1, with R2 and relative root mean squared error (RRMSE) values of about 0.57 and 9.6%, respectively. The performance of the general linear regression model increased with the number of variables; however, the improvement was ignorable when the number of variables was more than 30 and 50 for follow-up years 1 and 2, respectively. Although minor L1 and L2 regularization provided better prediction ability, the improvement was negligible when the number of variables was more than 20. All the models showed poorer performance for predicting QALYs at follow-up year 2.CONCLUSIONS: Patient characteristics before bariatric surgery including health related quality of life, age, sex, BMI, postoperative complications within six weeks, and smoking status, may be adequate in predicting their postoperative QALYs after one year. Understanding these factors can help identify individuals who require more personalized and intensive support before, during, and after surgery.
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| 3. |
- Sun, Sun, et al.
(författare)
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Sequential Multiple Imputation for Real-World Health-Related Quality of Life Missing Data after Bariatric Surgery
- 2022
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 19:17
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Tidskriftsartikel (refereegranskat)abstract
- One of the main challenges for the successful implementation of health-related quality of life (HRQoL) assessments is missing data. The current study examined the feasibility and validity of a sequential multiple imputation (MI) method to deal with missing values in the longitudinal HRQoL data from the Scandinavian Obesity Surgery Registry. All patients in the SOReg who received bariatric surgery between 1 January 2011 and 31 March 2019 (n = 47,653) were included for the descriptive analysis and missingness pattern exploration. The patients who had completed the short-form 36 (SF-36) at baseline (year 0), and one-, two-, and five-year follow-ups were included (n = 3957) for the missingness pattern simulation and the sequential MI analysis. Eleven items of the SF-36 were selected to create the six domains of SF-6D, and the SF-6D utility index of each patient was calculated accordingly. The multiply-imputed variables in previous year were used as input to impute the missing values in later years. The performance of the sequential MI was evaluated by comparing the actual values with the imputed values of the selected SF-36 items and index at all four time points. At the baseline and year 1, where missing proportions were about 20% and 40%, respectively, there were no statistically significant discrepancies between the distributions of the actual and imputed responses (all p-values > 0.05). In year 2, where the missing proportion was about 60%, distributions of the actual and imputed responses were consistent in 9 of the 11 SF-36 items. However, in year 5, where the missing proportion was about 80%, no consistency was found between the actual and imputed responses in any of the SF-36 items. Relatively high missing proportions in HRQoL data are common in clinical registries, which brings a challenge to analyzing the HRQoL of longitudinal cohorts. The experimental sequential multiple imputation method adopted in the current study might be an ideal strategy for handling missing data (even though the follow-up survey had a missing proportion of 60%), avoiding significant information waste in the multivariate analysis. However, the imputations for data with higher missing proportions warrant more research.
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| 4. |
- Sun, Sun, et al.
(författare)
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SF-6D Normative Values Among Patients Undergoing Bariatric Surgery : Results Based on Real-World Evidence from the Scandinavian Obesity Surgery Registry (SOReg)
- 2024
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Ingår i: Obesity Surgery. - : Springer. - 0960-8923 .- 1708-0428. ; 34:2, s. 558-567
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The SF-6D index can be used to calculate quality-adjusted life years in economic evaluations, which is required by reimbursement agencies and national advisory bodies, including the Swedish ones. However, despite that SF-36 has been largely applied among patients undergoing bariatric surgery, almost no study has accessed the short form six-dimensions (SF-6D) after bariatric surgery. AIM: To establish normative values for the SF-6D index among patients undergoing bariatric surgery.MATERIALS AND METHODS: All patients who received bariatric surgery in Sweden between 2011-01-01 and 2019-03-31 were obtained from the Scandinavian Obesity Surgery Registry (SOReg). Information includes patients' sociodemographic characteristics, details regarding the procedure, and postsurgical conditions. The SF-36 is applied at baseline and at follow-up years 1, 2, and 5. The multiple sequential imputation method was applied to handle missingness on SF-6D items. Based on the UK tariff, the SF-6D preference scores were calculated. The normative values for the mean (SD) SF-6D index were reported by timepoint and surgical complications for men and women, respectively. Multivariate analyses were applied to investigate how the SF-6D index is associated with timepoint, controlling for age, sex, BMI, and comorbidities in a stepwise manner.RESULTS: The SF-6D index increased at 1 year relative to baseline and was roughly maintained at the same level at 2 years. The normative value of the SF-6D index can be used in economic evaluations for bariatric surgery.
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| 5. |
- Cheah, Charissa S. L., et al.
(författare)
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Parenting hassles mediate predictors of Chinese and Korean immigrants' psychologically controlling parenting
- 2016
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Ingår i: Journal of applied developmental psychology. - : Elsevier. - 0193-3973 .- 1873-7900. ; 47, s. 13-22
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Tidskriftsartikel (refereegranskat)abstract
- We examined: (1) the mediating role of parenting daily hassles in the associations between three predictors (child temperament, maternal psychological well-being, and marital quality) and psychologically controlling practices in two Asian immigrant samples. We also explored the moderating role of maternal acculturation in the path from parenting daily hassles to psychological control. Participants were 152 Chinese and 165 Korean immigrant mothers with preschool children in the U.S. Multi-group path analysis revealed that easier child temperament, higher psychological well-being, and better marital quality were each associated with fewer parenting daily hassles, which in turn were associated with less psychological control. These general mediating effects held for both groups. However, the indirect effects of child temperament, maternal psychological well-being, and marital quality through parenting daily hassles were further moderated by acculturation for Chinese immigrant mothers, but not Korean immigrant mothers. The culturally similar and different findings across the two groups were discussed.
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| 6. |
- Pan, Yitao, et al.
(författare)
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First Report on the Occurrence and Bioaccumulation of Hexafluoropropylene Oxide Trimer Acid : An Emerging Concern
- 2017
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 51:17, s. 9553-9560
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Tidskriftsartikel (refereegranskat)abstract
- Here, we report on the occurrence of a novel perfluoroalkyl ether carboxylic acid, ammonium perfluoro-2-[(propoxy)propoxy]-1-propanoate (HFPO-TA), in surface water and common carp (Cyprinus carpio) collected from the Xiaoqing River and in 'residents residing near a fluoropolymer production plant in Huantai County, China. Compared with the levels upstream of the Xiaoqing River, HFPO-TA concentrations (5200-68500 ng/L) were approximately 120-1600-times higher downstream after receiving fluoropolymer plant effluent from a tributary. The riverine discharge' of HFPO-TA was estimated to be 4.6 t/yr, accounting for 22% of total PFAS discharge. In the wild common carp collected downstream from the point source, HFPO-TA was detected in the blood (median: 1510 ng/mL), liver (587 ng/g ww), and muscle (118 ng/g ww). The log BCFbiood of HFPO-TA (2.18) was significantly higher than that of PFOA (1.93). Detectable levels of HFPO-TA were also found in the sera of residents (median: 2.93 ng/mL). This is the first report on the environmental occurrence and bioaccumulation of this novel chemical. Our results indicate an emerging usage of HFPO-TA in the fluoropolymer manufacturing industry and raise concerns about the toxicity and potential health risks of HFPO-TA to aquatic organisms and humans.
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| 7. |
- Pan, Yitao, et al.
(författare)
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Worldwide Distribution of Novel Perfluoroether Carboxylic and Sulfonic Acids in Surface Water
- 2018
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 52:14, s. 7621-7629
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Tidskriftsartikel (refereegranskat)abstract
- Driven by increasingly stringent restrictions on long-chain per- and polyfluoroalkyl substances (PFASs), novel fluorinated compounds have emerged on the market. Here we report on the occurrences of several perfluoroalkyl ether carboxylic and sulfonic acids (PFECAs and PFESAs), including hexafluoropropylene oxide dimer and trimer acids (HFPO-DA and HFPO-TA), ammonium 4,8-dioxa-3 H-perfluorononanoate (ADONA), chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA), and its hydrogen-substituted analogue (6:2 H-PFESA) in surface waters from China ( n = 106), the United States ( n = 12), the United Kingdom ( n = 6), Sweden ( n = 10), Germany ( n = 14), The Netherlands ( n = 6), and Korea ( n = 6). Results showed that HFPO-DA, HFPO-TA, and 6:2 Cl-PFESA (median = 0.95, 0.21, and 0.31 ng/L, respectively) were frequently detected in all countries, indicating ubiquitous dispersal and distribution in global surface waters. The presence of 6:2 H-PFESA was widely detected in China (detection rate > 95%) but not in any other country. Only trace levels of ADONA (0.013-1.5 ng/L) were detected in the Rhine River flowing through Germany. The estimated total riverine mass discharges of HFPO-DA, HFPO-TA, and ΣPFESAs reached 2.6, 6.0, and 4.3 ton/year in five of the major river systems in China. Our results indicated that novel PFECAs and PFESAs might become global contaminants, and future investigations are warranted.
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