OBJECTIVE: Adjusting for potential confounders is crucial for producing valuable evidence in outcome studies. Although numerous studies have been published using the Korea National Health Insurance Claim Database, no study has critically reviewed the methods used to adjust for confounders. This study aimed to review these studies and suggest methods and applications to adjust for confounders.
METHODS: We conducted a literature search of electronic databases, including PubMed and Embase, from January 1, 2021 to December 31, 2022. In total, 278 studies were retrieved. Eligibility criteria were published in English and outcome studies. A literature search and article screening were independently performed by 2 authors and finally, 173 of 278 studies were included.
RESULTS: Thirty-nine studies used matching at the study design stage, and 171 adjusted for confounders using regression analysis or propensity scores at the analysis stage. Of these, 125 conducted regression analyses based on the study questions. Propensity score matching was the most common method involving propensity scores. A total of 171 studies included age and/or sex as confounders. Comorbidities and healthcare utilization, including medications and procedures, were used as confounders in 146 and 82 studies, respectively.
CONCLUSIONS: This is the first review to address the methods and applications used to adjust for confounders in recently published studies. Our results indicate that all studies adjusted for confounders with appropriate study designs and statistical methodologies; however, a thorough understanding and careful application of confounding variables are required to avoid erroneous results.

Measurement of surgical quality at a population level is challenging. Composite quality measures derived from administrative and clinical information systems could support system-wide surgical quality improvement by providing a simple metric that can be evaluated over time. The aim of this systematic review was to identify published studies of composite measures used to assess the overall quality of abdominal surgical services at a hospital or population level.
A search was conducted in PubMed and MEDLINE for references describing measurement instruments evaluating the overall quality of abdominal surgery. Instruments combining multiple process and quality indicators into a single composite quality score were included. The identified instruments were described in terms of transparency, justification, handling of missing data, case-mix adjustment, scale branding and choice of weight and uncertainty to assess their relative strengths and weaknesses (PROSPERO registration: CRD42022345074).
Of 5234 manuscripts screened, 13 were included. Ten unique composite quality measures were identified, mostly developed within the past decade. Outcome measures such as mortality rate (40 per cent), length of stay (40 per cent), complication rate (60 per cent) and morbidity rate (70 per cent) were consistently included. A major challenge for all instruments is the reliance of valid administrative data and the challenges of assigning appropriate weights to the underlying instrument components. A conceptual framework for composite measures of surgical quality was developed.
None of the composite quality measures identified demonstrated marked superiority over others. The degree to which administrative and clinical data influences each composite measure differs in important ways. There is a need for further testing and development of these measures.

BACKGROUND: Overweight and obesity and their consequent morbidities are important worldwide health problems. Some research suggests excess adiposity origins may begin in fetal life, but unknown is whether this applies to infants born preterm.
OBJECTIVE: The objective of the study was to assess the association between small for gestational age (SGA) birth and later adiposity and height among those born preterm.
METHODS: MEDLINE, EMBASE and CINAHL until October 2022.
METHODS: Studies were included if they reported anthropometric (adiposity measures and height) outcomes for participants born preterm with SGA versus non-SGA. Screening, data extraction and risks of bias assessments were conducted in duplicate by two reviewers.
RESULTS: We meta-analysed across studies using random-effects models and explored potential heterogeneity sources.
RESULTS: Thirty-nine studies met the inclusion criteria. In later life, preterm SGA infants had a lower body mass index (-0.66 kg/m2 , 95% CI -0.79, -0.53; 32 studies, I2  = 16.7, n = 30,346), waist circumference (-1.20 cm, 95% CI -2.17, -0.23; 13 studies, I2  = 19.4, n = 2061), lean mass (-2.62 kg, 95% CI -3.45, 1.80; 7 studies, I2  = 0, n = 205) and height (-3.85 cm, 95% CI -4.73, -2.96; 26 studies, I2  = 52.6, n = 4174) compared with those preterm infants born non-SGA. There were no differences between preterm SGA and preterm non-SGA groups in waist/hip ratio, body fat, body fat per cent, truncal fat per cent, fat mass index or lean mass index, although power was limited for some analyses. Studies were rated at high risk of bias due to potential residual confounding and low risk of bias in other domains.
CONCLUSIONS: Compared to their preterm non-SGA peers, preterm infants born SGA have lower BMI, waist circumference, lean body mass and height in later life. No differences in adiposity were observed between SGA preterm infants and non-SGA preterm infants.

BACKGROUND: Historical reports suggest that infants born small for gestational age (SGA) are at increased risk for high blood pressure (BP) at older ages after adjustment for later age body size. Such adjustment may be inappropriate since adiposity is a known cause of cardiovascular and metabolic disease.
OBJECTIVE: To assess the association between SGA births and later BP among preterm births, considering potential background confounders and over-adjustment for later body size.
METHODS: A database search of studies up to October 2022 included MEDLINE, EMBASE and CINAHL. Studies were included if they reported BP (systolic [SBP] or diastolic [DBP]) (outcomes) for participants born preterm with SGA (exposure) or non-SGA births. All screening, extraction steps, and risk of bias (using the Risk of Bias In Non-randomised Studies of Interventions [ROBINS-I] tool) were conducted in duplicate by two reviewers. Data were pooled in meta-analysis using random-effects models. We explored potential sources of heterogeneity.
RESULTS: We found no meaningful difference in later BP between preterm infants with and without SGA status at birth. Meta-analysis of 25 studies showed that preterm SGA, compared to preterm non-SGA, was not associated with higher BP at age 2 and older with mean differences for SBP 0.01 mmHg (95% CI -0.10, 0.12, I2  = 59.8%, n = 20,462) and DBP 0.01 mm Hg (95% CI -0.10, 0.12), 22 studies, (I2  = 53.0%, n = 20,182). Adjustment for current weight did not alter the results, which could be due to the lack of differences in later weight status in most of the included studies. The included studies were rated to be at risk of bias due to potential residual confounding, with a low risk of bias in other domains.
CONCLUSIONS: Evidence indicates that preterm infants born SGA are not at increased risk of developing higher BP as children or as adults as compared to non-SGA preterm infants.

Value-based payment programs adjust payments to providers based on spending, quality, or health outcomes. Concern that these programs penalize providers disproportionately serving vulnerable patients prompted calls to adjust performance measures for social risk factors. We reviewed fourteen studies of social risk adjustment in Medicare\'s Hospital Readmissions Reduction Program (HRRP), a value-based payment model that initially did not adjust for social risk factors but subsequently began to do so. Seven studies found that adding social risk factors to the program\'s base risk-adjustment model (which adjusts only for age, sex, and comorbidities) reduced differences in risk-adjusted readmissions and penalties between safety-net hospitals and other hospitals. Three studies found that peer grouping, the HRRP\'s current approach to social risk adjustment, reduced penalties among safety-net hospitals. Two studies found that differences in risk-adjusted readmissions and penalties were further narrowed when augmentation of the base model was combined with peer grouping. Two studies showed that it is possible to adjust for social risk factors without obscuring quality differences between hospitals. These findings support the use of social risk adjustment to improve provider payment equity and highlight opportunities to enhance social risk adjustment in value-based payment programs.

Background: Capitation payment is the best-known strategy for paying providers in primary health care. Since health care needs and personal characteristics play an essential role in health care utilization and resource spending, there is a growing tendency on risk adjustment models among health researchers. The objective of this systematic review was to examine the weights used for risk adjustment in primary health care capitation payment. Methods: We systematically searched Scopus, ProQuest, Web of Science, and PubMed in March 2018. Two authors independently apprised the included articles and they also evaluated, identified, and categorized different factors on capitation payments mentioned in the included studies. Results: A total of 742 studies were identified and 12 were included in the systematic review after the screening process. Risk factors for capitation adjustment included age, gender, and income with the weighted average being 1.76 and 1.03, respectively. Moreover, the weighted average disease incidence adjusted clinical groups (ACGs), diagnostic cost groups (DCGs), principal in patient diagnostic cost groups (PIP-DCGs), and hierarchical coexisting conditions (HCCs) were reported as 1.31, 24.7-.99, 10.4-.65, and 11.7-1.01, respectively. Conclusion: In low-income countries, the most effective factors used in capitation adjustment are age and sex. Moreover, the most applied factor in high-income countries is adjusted clinical groups, and income factors can have a better impact on the reduction of costs in low-income countries. Each country can select its most efficient factors based on the weight of the factor, income level, and geographical condition.

The complexity of pancreaticoduodenectomy and fear of morbidity, particularly postoperative pancreatic fistula, can be a barrier to surgical trainees gaining operative experience. This meta-analysis sought to compare the postoperative pancreatic fistula rate after pancreatoenteric anastomosis by trainees or established surgeons.
A systematic review of the literature was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, with differences in postoperative pancreatic fistula rates after pancreatoenteric anastomosis between trainee-led versus consultant/attending surgeons pooled using meta-analysis. Variation in rates of postoperative pancreatic fistula was further explored using risk-adjusted outcomes using published risk scores and cumulative sum control chart analysis in a retrospective cohort.
Across 14 cohorts included in the meta-analysis, trainees tended toward a lower but nonsignificant rate of all postoperative pancreatic fistula (odds ratio: 0.77, P = .45) and clinically relevant postoperative pancreatic fistula (odds ratio: 0.69, P = .37). However, there was evidence of case selection, with trainees being less likely to operate on patients with a pancreatic duct width <3 mm (odds ratio: 0.45, P = .05). Similarly, analysis of a retrospective cohort (N = 756 cases) found patients operated by trainees to have significantly lower predicted all postoperative pancreatic fistula (median: 20 vs 26%, P < .001) and clinically relevant postoperative pancreatic fistula (7 vs 9%, P = .020) rates than consultant/attending surgeons, based on preoperative risk scores. After adjusting for this on multivariable analysis, the risks of all postoperative pancreatic fistula (odds ratio: 1.18, P = .604) and clinically relevant postoperative pancreatic fistula (odds ratio: 0.85, P = .693) remained similar after pancreatoenteric anastomosis by trainees or consultant/attending surgeons.
Pancreatoenteric anastomosis, when performed by trainees, is associated with acceptable outcomes. There is evidence of case selection among patients undergoing surgery by trainees; hence, risk adjustment provides a critical tool for the objective evaluation of performance.

The coronavirus disease 2019 (COVID-19) pandemic has taken a disproportionate toll on long-term care facility residents and staff. Our objective was to review the empirical evidence on facility characteristics associated with COVID-19 cases and deaths.
Systematic review.
Long-term care facilities (nursing homes and assisted living communities).
Thirty-six empirical studies of factors associated with COVID-19 cases and deaths in long-term care facilities published between January 1, 2020 and June 15, 2021.
Outcomes included the probability of at least one case or death (or other defined threshold); numbers of cases and deaths, measured variably.
Larger, more rigorous studies were fairly consistent in their assessment of risk factors for COVID-19 outcomes in long-term care facilities. Larger bed size and location in an area with high COVID-19 prevalence were the strongest and most consistent predictors of facilities having more COVID-19 cases and deaths. Outcomes varied by facility racial composition, differences that were partially explained by facility size and community COVID-19 prevalence. More staff members were associated with a higher probability of any outbreak; however, in facilities with known cases, higher staffing was associated with fewer deaths. Other characteristics, such as Nursing Home Compare 5-star ratings, ownership, and prior infection control citations, did not have consistent associations with COVID-19 outcomes.
Given the importance of community COVID-19 prevalence and facility size, studies that failed to control for these factors were likely confounded. Better control of community COVID-19 spread would have been critical for mitigating much of the morbidity and mortality long-term care residents and staff experienced during the pandemic. Traditional quality measures such as Nursing Home Compare 5-Star ratings and past deficiencies were not consistent indicators of pandemic preparedness, likely because COVID-19 presented a novel problem requiring extensive adaptation by both long-term care providers and policymakers.

Cancer is a leading cause of venous thromboembolism (VTE), which contributes to significant morbidity and mortality in these patients. Increased thrombotic risk in cancer patients is modified by tumor-specific biology, disease-directed interventions, and individual comorbidities. Risk stratification for prophylaxis and treatment requires regular reevaluation of these factors, which can be facilitated by validated prediction tools. This review also discusses large clinical trial data (SELECT-D, HOKUSAI-VTE, ADAM VTE, CARAVAGGIO) demonstrating that direct oral anticoagulants (DOACs) are effective in the treatment of cancer-associated VTE, with comparable efficacy to the traditional choice of low molecular weight heparin. In the prophylactic setting derived from patients with cancer with increased VTE risk, DOACs also reduced the incidence of VTE with only modest increases in bleeding risk. The ease of DOAC administration and acceptable risk profile in the carefully selected patient make them an appealing choice for anticoagulation. In instances where the risk of gastrointestinal bleeding is of concern, apixaban, in particular, may still be a suitable option in place of LMWH. These improvements in our anticoagulation approach to cancer-associated VTE are well-timed to accompany the recent advances in disease-directed therapies that are enabling patients to live longer with cancer and therefore at increased risk of complications such as VTE.

UNASSIGNED: This network meta-analysis aimed to evaluate the efficacy and safety of different dual antiplatelet therapies (DAPTs) after percutaneous coronary intervention (PCI) with drug-eluting stents (DESs).
UNASSIGNED: Randomized controlled trials (RCTs) comparing longer-term (>12 months) DAPT (L-DAPT), 12-month DAPT (DAPT 12Mo), 6-month DAPT (DAPT 6Mo), 3-month DAPT followed by aspirin monotherapy (DAPT 3Mo + ASA), 3-month DAPT followed by a P2Y12 receptor inhibitor monotherapy (DAPT 3Mo + P2Y12), or 1-month DAPT with a P2Y12 receptor inhibitor monotherapy (DAPT 1Mo + P2Y12) were searched. Primary endpoints were all-cause mortality, cardiac death, myocardial infarction (MI), major bleeding, any bleeding, definite or probable stent thrombosis (ST), and net adverse clinical events (NACE). This Bayesian network meta-analysis was performed with the random-effects model.
UNASSIGNED: Twenty-four RCTs (n = 81339) were included. In comparison with L-DAPT, DAPT 6Mo (OR: 0.50, 95% CI: 0.29-0.83), DAPT 3Mo + P2Y12 (OR: 0.38, 95% CI: 0.18-0.82), DAPT 3Mo + ASA (OR: 0.44, 95% CI: 0.17-0.98), and DAPT 1Mo + P2Y12 (OR: 0.45, 95% CI: 0.14-0.93) were associated with a lower risk of major bleeding. DAPT 3Mo + P2Y12 (OR: 0.58, 95% CI: 0.38-0.88) reduced the risk of any bleeding when compared with DAPT 12Mo. L-DAPT decreased the risk of MI and definite or probable stent ST when compared with DAPT 6Mo. DAPT 3Mo + P2Y12 decreased the risk of NACE in comparison with DAPT 6Mo and DAPT 12Mo. No significant difference in all-cause mortality and cardiac death was observed. In patients with acute coronary syndrome, DAPT 6Mo was comparable to DAPT 12Mo.
UNASSIGNED: Short-term (1-3 months) DAPT is noninferior to DAPT 6Mo after DESs implantation, while L-DAPT reduces MI and definite or probable ST rates. DAPT 3Mo + P2Y12 might be a reasonable trade-off in patients with high risk of bleeding accompanied by ischemia.