Interaction and Its Solution in Individual Matching Case-control Study

Objective To indicate the deficiency of the classical method for analyzing data on individual matching case-control study in consideration of the interaction between the study factor (exposure) and the matching factor, and to find out a proper method for handling this deficiency. Method First, experimental data with 50 pairs of cases and controls were used for strata analysis according to the values of a matching factor to illustrate the possible interaction between a risk factor (exposure) and the matching factor. Second, a detailed procedure was proposed for analyzing such data. Results Interaction between the study factor and matching factor was demonstrated by using strata analysis and unconditional logistic regression analysis. Therefore the results from the classical analysis for such data might be incorrect. Conclusion Data from individual matching case-control study design should be dealt with strata analysis or multivariate analysis to explore and evaluate the possible interaction between the s

Risk factors related to female breast cancer in regions of Northeast China： a 1：3 matched case-control population-based study

Background There has been an increase in the incidence of breast cancer in China, but no definite risk and protective factors for breast cancer have been identified in Chinese females. This study was designed to identify the risk factors for female breast cancer in North and East China.

A matched cohort study of laparoscopy-assisted and open total gastrectomy for advanced proximal gastric cancer without serosa invasion

Background Little is known about the feasibility and safety of laparoscopy-assisted total gastrectomy （LATG） with extended lymphadenectomy in patients with advanced gastric cancer （AGC）.This study compared the technical feasibility,safety,and oncologic efficacy of LATG with open total gastrectomy （OTG） for AGC without serosa invasion.Methods From January 2009 to December 2011,235 patients underwent LATG and 153 patients underwent OTG for AGC without serosa invasion.Age,gender,and depth of invasion （pT2 and pT3） were matched by propensity scoring,and 116 patients （58 LATG and 58 OTG） were selected for analysis.Their clinicopathologic characteristics,postoperative outcomes,and survival were compared.Results There was no significant difference in clinicopathologic characteristics between the two propensity-matched groups.Median number of lymph nodes per patient was 29,and the mean number of retrieved lymph nodes was similar in the LATG and OTG groups （30.8±10.2 vs.29.0±8.3）.Peri-operative characteristics,operation time,number of transfused units per patient,and time to resumption of activities were similar in the two groups; while blood loss,times to first flatus and resumption of soft diet,and post-operative stay were significantly lower in the LATG group （P ＜0.05,respectively）.Rates of post-operative complications （12.1％ vs.15.5％） and postoperative mortality （0％ vs.1.7％）,as well as cumulative survival rates,were similar.Conclusions LATG with D2 lymphadenectomy is a safe and feasible procedure for AGC patients without serosa invasion.ProsPective.multicenter,randomized trials are needed to confirm the efficacy of LATG in this patient population.

Diabetes Is Not Associated with Increased 10-week Mortality Risk in Patients with Cryptococcal Meningitis

Background:Diabetes is a risk factor for acquisition of cryptococcal meningitis(CM).However,the effects of diabetes on outcomes of CM patient have not been fully studied.Methods:In this retrospective study,49 diabetic CM patients and 98 non-diabetic CM patients from January 2008 to December 2018 in the First Affiliated Hospital of Zhejiang University were included by propensity score-matched method(1:2).Demographic characteristics,symptoms,and clinical assay parameters between the two groups were compared.Kaplan-Meier analysis and Cox proportional hazards model were used to assess factors associated with 10-week mortality.Results:The mean age of diabetic patients was 58.2±13.8 years;71.4%(35/49)were more than 50 years old and 46.9%were male.No difference in symptoms was found between diabetic and non-diabetic CM patients.The Charlson comorbidity score was higher in the diabetic group(1.9 vs.0.7,P<0.001).CM patients with diabetes had higher white blood cells count(106/L,111.0(18.0–242.5)vs.50.0(10.0–140.0),P=0.034)in cerebrospinal fluid(CSF),lower CSF India ink positivity(40.8%vs.60.2%,P=0.039),and Cryptococcus culture positivity(42.9%vs.60.2%,P=0.047).The overall 10-week survival rate was 79.7%in diabetic patients vs.83.2%in non-diabetic patients(log-rank P=0.794).Conclusion:Diabetic CM patients have higher CSF glucose and Charlson comorbidity score,but lower CSF India ink and culture positivity than non-diabetic CM patients.No difference in 10-week mortality was found between patients with and without diabetes.Other comorbidities may have a greater effect on prognosis.