Prognostic models and the propensity score

Short-term outcomes after open versus robot-assisted repair of ventral hernias: a nationwide database study

PURPOSE

The robotic platform is widely implemented; however, evidence evaluating outcomes of robotic ventral hernia repair is still lacking. The aim of the study was to evaluate the short-term outcomes after open and robot-assisted repair of primary ventral and incisional hernias.

METHODS

Nationwide register-based cohort study with data from the Danish Ventral Hernia Database and the National Danish Patients Registry was from January 1, 2017 to August 22, 2022. Robot-assisted ventral hernia repairs were propensity score matched 1:3 with open repairs according to the confounding variables defect size, Charlson comorbidity index score, and age. Logistic regression analyses were performed for factors associated with length of stay > 2 days, readmission, and reoperation within 90 days.

RESULTS

A total of 528 and 1521 patients underwent robot-assisted and open repair, respectively. The mean length of hospital stay in days was 0.5 versus 2.1 for robot-assisted and open approach, respectively (P < 0.001) and open approach was correlated with risk of length of stay > 2 days (OR 23.25, CI 13.80-39.17, P < 0.001). The incidence of readmission within 90 days of discharge was significantly lower after robot-assisted repair compared to open approach (6.2% vs. 12.1%, P < 0.001). Open approach was independently associated with increased risk of readmission (OR 21.43, CI 13.28-39.17, P = 0.005, P < 0.001).

CONCLUSION

Robot-assisted ventral hernia repair is safe and feasible and associated with shorter length of stay and decreased risk of readmission compared with open ventral hernia repair.

Prognostic factors and treatment considerations of submandibular gland carcinomas: A population-based study

OBJECTIVES

The therapeutic regimen of submandibular gland carcinoma (SGC) has not reached consensus, especially for the neck treatment of patients with cN0.

MATERIALS AND METHODS

Patients with SGC were identified from the medical database of Shanghai Ninth People's Hospital. Kaplan-Meier analysis, univariate and multivariate Cox regression were employed to evaluate the survival and independent prognostic factors.

RESULTS

Two hundred and fifteen patients with SGC were retrospectively reviewed. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 71.5% and 77.8%, respectively. Multivariate analysis revealed that histological grade, cT classification, cN classification, and perineural invasion (PNI) were independent prognostic factors for DFS, while histological grade, cT classification, cN classification, and age were those for OS. The neck dissection showed no significant survival benefit for patients with cN0. Lung was the most common site of distant metastasis (16.7%).

CONCLUSIONS

Histological grade, cT classification, cN classification, age, and PNI were independent prognostic factors of patient with SGC, which should be the main considerations for making therapeutic regimens. Our study also verifies the neck dissection of patient with cN0 is unnecessary, and postoperative radiotherapy (PORT) is vital for patients with pN+.

Sublaminar Tethers Significantly Reduce the Risk of Proximal Junctional Failure in Surgery for Severe Adult Spinal Deformity: A Propensity Score-matched Analysis

STUDY DESIGN

This was a retrospective case series of prospectively collected data.

OBJECTIVE

The present study first described the effect of sublaminar tethering (SLT) on proximal junctional failure (PJF) in adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND DATA

PJF is a devastating complication following ASD surgery. Teriparatide administration and spinous process tethering have been reported as alternatives for the prevention of PJF, but a clinically effective prevention strategy is still a matter of debate.

MATERIALS AND METHODS

We used data from an ASD database that included 381 patients with ASD (minimum 2-y follow-up). Among them, the data of patients who had a severe sagittal deformity and had surgery from the lower thoracic spine (T9-T11) to the pelvis were extracted and propensity score matched by age, sex, body mass index, bone mineral density, curve type, sagittal alignment, and fused level to clarify whether SLT prevented the development of PJF [SLT vs. control (CTR); age: 67±7 vs. 66±8 y, T-score: -1.4±0.7 vs. -1.3±0.6, body mass index: 22±4 vs. 22±5 kg/m2, C7 sagittal vertical axis (C7SVA): 12±7 vs. 11±5 cm, pelvic incidence-lumbar lordosis (PI-LL): 51±22 vs. 49±21 degrees, pelvic tilt (PT): 36±10 vs. 34±10 degrees, level fused: 11±2 vs. 11±2]. Sixty-four patients were matched into 32 pairs and compared in terms of the postoperative alignment and frequency of PJF.

RESULTS

Two years postoperatively, C7SVA and PT were significantly larger in the CTR group, while no significant difference in PI-LL was found (C7SVA: 3±3 vs. 6±4 cm, P<0.01, PT: 16±6 vs. 24±9 degrees, P<0.01, PI-LL: 7±9 vs. 11±11 degrees, P=0.22). The proximal junctional angle was significantly greater in the CTR group (proximal junctional kyphosis: 8±8 vs. 17±13 degrees, P<0.01). The incidence of PJF was significantly lower in the SLT group (3% vs. 25%, P=0.03), with an odds ratio of 0.1 (95% confidence interval: 0.0-0.8, P=0.03).

CONCLUSION

In the propensity score-matched cohort, the incidence of PJF was significantly lower in the SLT group. SLT is a promising procedure that may reduce the risk of PJF in severe ASD surgery.

The Risk of Clostridioides difficile Recurrence after Initial Treatment with Vancomycin or Fidaxomicin Utilizing Cerner Health Facts

(1) Background: Fidaxomicin has been shown to significantly reduce Clostridioides difficile infection (CDI) recurrences rates in randomized, controlled trials. However, national data from the Veterans Affairs has called the real-world applicability of these findings into question. Therefore, we conducted a retrospective cohort study of patients receiving fidaxomicin or vancomycin as initial therapy for an index case of CDI in the hospital to evaluate the relative rates CDI recurrence within 90 days of an index case. (2) Methods: We retrieved patients 18 years and older who were admitted between July 2011 through June 2018 and diagnosed and treated for CDI with vancomycin or fidaxomicin. The first occurrence of CDI with treatment was designated as the index case. Patients with CDI within 1 year prior to index case were excluded. From the remaining index cases (vancomycin = 14,785; fidaxomicin = 889) the primary outcome (a recurrence of CDI within 90 days of the index case) was determined. The CDI recurrence rates for fidaxomicin and vancomyicn were evaluated using a Cox Proportional Hazards model on a propensity score matched cohort. (3) Results: A statistically significantly lower risk of CDI recurrence was observed with fidaxomicin use in the matched cohort (889 patients per treatment) using a Cox Proportional Hazards model (HR 0.67, 95% CI 0.50–0.90). (4) Conclusions: Fidaxomicin was independently associated with a decreased CDI recurrence, as defined by readmission for CDI within 90 days.

Thrombocytopenia and Clinical Outcomes in Intracerebral Hemorrhage: A Retrospective Multicenter Cohort Study

BACKGROUND AND PURPOSE

The impact of platelets on hematoma enlargement (HE) of intracerebral hemorrhage (ICH) is not yet sufficiently elucidated. Especially the role of reduced platelet counts on HE and clinical outcomes is still poorly understood. This study investigated the influence of thrombocytopenia on HE, functional outcome, and mortality in patients with ICH with or without prior antiplatelet therapy (APT).

METHODS

Individual participant data of multicenter cohort studies (multicenter RETRACE program [German-Wide Multicenter Analysis of Oral Anticoagulation-Associated Intracerebral Hemorrhage] and single-center UKER-ICH registry [Universitätsklinikum Erlangen Cohort of Patients With Spontaneous ICH]) were grouped into APT and non-APT ICH patients according to the platelet count, that is, with or without thrombocytopenia (cells <150×10⁹/L). Of all patients, 51.5% (1124 of 2183) were on vitamin K antagonist. Imbalances in baseline characteristics including proportions of vitamin K antagonist patients were addressed using propensity score matching. Outcome analyses included HE (>33%), as well as mortality and functional outcome, after 3 months using the modified Rankin Scale, dichotomized into favorable (modified Rankin Scale score, 0-3) and unfavorable (modified Rankin Scale score, 4-6).

RESULTS

Of overall 2252 ICH patients, 11.4% (52 of 458) under APT and 14.0% (242 of 1725) without APT presented with thrombocytopenia on admission. The proportion of patients with HE was not significantly different between patients with or without thrombocytopenia among APT and non-APT ICH patients after propensity score matching (HE: APT patients: 9 of 40 [22.5%] thrombocytopenia versus 27 of 115 [23.5%] nonthrombocytopenia, P=0.89; non-APT patients: 54 of 174 [31.0%] thrombocytopenia versus 106 of 356 [29.8%] nonthrombocytopenia, P=0.77). In both (APT and non-APT) propensity score matching cohorts, there were no significant differences regarding functional outcome. Mortality after 3 months did not differ among non-APT patients, whereas the mortality rate was significantly higher for APT patients with thrombocytopenia versus APT patients with normal platelet count (APT: 29 of 46 [63.0%] thrombocytopenia versus 58 of 140 [41.4%] nonthrombocytopenia, P=0.01; non-APT: 95 of 227 [41.9%] thrombocytopenia versus 178 of 455 [39.1%] nonthrombocytopenia, P=0.49).

CONCLUSIONS

Our study implies that thrombocytopenia does not affect rates of HE and functional outcome among ICH patients, neither in patients with nor without APT. In light of increased mortality, the significance of platelet transfusions for ICH patients with thrombocytopenia and previous APT should be explored in future studies.

Pre-Existing Diabetes Limits Survival Rate After Immune Checkpoint Inhibitor Treatment for Advanced Lung Cancer: A Retrospective Study in Japan

BACKGROUND

Although immune checkpoint inhibitors (ICIs) are promising in the treatment of advanced cancer, their use is associated with immune-related adverse events (irAEs) that affect endocrine organ systems. Although development of irAEs was associated with improved cancer-specific survival, the risk of irAEs is unclear. We investigated the association of pre-ICI comorbidities-including diabetes-with irAEs, overall survival (OS), and progression-free survival (PFS) in advanced lung cancer.

METHODS

Patients with lung cancer who were treated with ICIs during the period from September 1, 2015 through July 31, 2018 were retrospectively enrolled. All data were collected from the NEPTUNE database of university patients. Hazard ratios were estimated by using Cox regression weighted for propensity scores. Odds ratios were calculated by logistic regression and adjusted for unbalanced variables. The Kaplan-Meier method was used to compare OS, and the generalized Wilcoxon test was used to compare median survival.

RESULTS

Among the 88 patients identified, 22 (25.0%) had diabetes (DM) before ICI treatment and 57 (75.0%) did not (non-DM); irAEs developed in 12.2% of patients with DM and in 9.1% of patients in non-DM (p=0.87). Diabetes status was not associated with irAE risk in relation to baseline characteristics (age, sex, TNM staging, thyroid and renal function) or in propensity score-matched analysis (age, TNM staging). During a mean follow-up of 30 months, OS and cancer-specific PFS were significantly higher in patients who developed irAEs (Kaplan-Meier estimates, p=0·04 and 0·03, respectively). In propensity score-matched analysis, diabetes was significantly associated with lower OS (multivariate hazard ratio, 0·36; 95% CI, 0·13-0·98) unrelated to irAEs. Irrespective of irAEs, PFS was also lower among patients with DM than among non-DM patients (Kaplan-Meier estimate, p=0·04).

CONCLUSION

Pre-existing diabetes was associated with higher mortality in advanced lung cancer, regardless of irAE development during treatment with ICI.

Lactic acidosis incidence with metformin in patients with type 2 diabetes and chronic kidney disease: A retrospective nested case-control study

Objective

Compare rates of lactic acidosis (LA) among metformin-exposed and unexposed patients with type 2 diabetes mellitus and varying degrees of chronic kidney disease (CKD).

Research Design and Methods

Retrospective, nested case-control study using data from national VA Corporate Data Warehouse. All adult patients with type 2 diabetes and CKD newly dispensed any antihyperglycaemic medication during FY 2003-13 were included. The outcome was LA hospitalization or serum lactate >5 mEq/L. Exposure to metformin was evaluated in the three months prior to event. Estimates were adjusted for 31 covariates, including demographics, comorbidities and medications.

Results

Overall, 320 882 patients were included, contributing a total of 1 331 784 person-years of follow-up. LA occurred in 2 665 patients, generating an overall incidence rate of 2.00 (95% CI 1.93-2.08) per 1000 person-years. Metformin exposure in the prior 3 months was associated with an elevated adjusted hazard of LA (HR 1.97, 95% CI 1.69-2.29). No association was evident in patients with CKD stage 1 or 2 (HR 1.05, 95% CI 0.71-1.57), but associations were present and progressively greater in patients with CKD stage 3a through 5: HR 3.09, 95% CI 2.19-4.35 in CKD 3a, HR 3.34, 95% CI 1.95-5.72 in CKD 3b, HR 7.87, 95% CI 3.51-17.61 in CKD stage 4&5.

Conclusion

Metformin was not associated with an elevated risk of LA in persons with stage 1-2 CKD, but was associated with a progressively higher risk at more advanced stages of CKD.

Clinical Outcomes, Complications, and Cost-effectiveness in Surgically Treated Adult Spinal Deformity Over 70 Years: A Propensity score-Matched Analysis

STUDY DESIGN

This is a multicentered retrospective study.

SUMMARY OF BACKGROUND DATA

Surgical correction for the adult spinal deformity (ASD) is effective but carries substantial risks for complications. The diverse pathologies of ASD make it difficult to determine the effect of advanced age on outcomes.

OBJECTIVE

The objective of this study was to assess how advanced age affects outcomes and cost-effectiveness for corrective surgery for ASD.

MATERIALS AND METHODS

We used data from a multicenter database to conduct propensity score-matched comparisons of 50 patients who were surgically treated for ASD when at least 50 years old and were followed for at least 2 years, to clarify whether advanced age is a risk factor for inferior health-related quality of life and cost-effectiveness. Patients were grouped by age, 50-65 years (M group: 59±4 y) or >70 years (O group: 74±3 y), and were propensity score-matched for sex, body mass index, upper and lower instrumented vertebrae, the use of pedicle-subtraction osteotomy, and sagittal alignment. Cost-effectiveness was determined by cost/quality-adjusted life years.

RESULTS

Oswestry Disability Index and Scoliosis Research Society-22 (SRS-22) pain and self-image at the 2-year follow-up were significantly inferior in the O group (Oswestry Disability Index: 32±9% vs. 25±13%, P=0.01; SRS-22 pain: 3.5±0.7 vs. 3.9±0.6, P=0.05; SRS-22 self-image: 3.5±0.6 vs. 3.8±0.9, P=0.03). The O group had more complications than the M group (55% vs. 29%). The odds ratios in the O group were 4.0 for postoperative complications (95% confidence interval: 1.1-12.3) and 4.9 for implant-related complications (95% confidence interval: 1.2-21.1). Cost-utility analysis at 2 years after surgery indicated that the surgery was less cost-effective in the O group (cost/quality-adjusted life year: O group: $211,636 vs. M group: 125,887, P=0.01).

CONCLUSIONS

Outcomes for corrective surgery for ASD were inferior in geriatric patients compared with middle-aged patients, in whom the extent of spinal deformity and the operation type were adjusted similarly. Special attention is needed when considering surgical treatment for geriatric ASD patients.

Should a neck dissection be performed on patients with cN0 adenoid cystic carcinoma? A REFCOR propensity score matching study

BACKGROUND

Patterns of nodal involvement in adenoid cystic carcinoma (ACC) of the head and neck have not been sufficiently assessed to guide a decision of prophylactic neck dissection (ND). The objective of this study is to analyse the influence of ND on event-free survival (EFS) for patients with cN0 ACC.

PATIENTS AND METHODS

A multicentre prospective study was conducted between 2009 and 2018. Patients presenting cN0 non-metastatic ACC on any site, and who received surgery on the tumour, were included. EFS was the main judgement criterion. A comparative survival analysis between the groups that received a ND versus those that did not was performed, using a propensity score. Analyses were carried out using the R software.

RESULTS

Between 2009 and 2018, 322 patients with cN0 ACC were included, out of which 58% were female. The average age was 53 years. Tumours were in minor salivary glands in 58% of cases, and 52% had T3/T4 stages. ND was performed on 46% of patients. Out of them, seven had histological lymph node invasion, out of which six had tumour infiltration in the mucosa of oral cavity. After propensity score, the median EFS for N0 patients with ND was 72 months (95% Confidence Interval (CI) [48-81]), compared to 73 months (95% CI [52-85]) for patients without ND (HR = 1.33; 95% CI [0.82-2.16]; p = 0.2).

CONCLUSION

ND of cN0 patients does not provide any benefit on EFS, which suggests that its application on such patients is not necessary.

Age-dependent clinical outcomes in primary versus oral anticoagulation-related intracerebral hemorrhage

AIMS

This study determined the influence of age on bleeding characteristics and clinical outcomes in primary spontaneous (non-OAC), vitamin K antagonist-related (VKA-) and non-vitamin K antagonist oral anticoagulant-related (NOAC-) ICH.

METHODS

Pooled individual patient data of multicenter cohort studies were analyzed by logistic regression modelling and propensity-score-matching (PSM) to explore the influence of advanced age on clinical outcomes among non-OAC-, VKA-, and NOAC-ICH. Primary outcome measure was functional outcome at three months assessed by the modified Rankin Scale, dichotomized into favorable (mRS = 0-3) and unfavorable (mRS = 4-6) functional outcome. Secondary outcome measures included mortality, hematoma characteristics, and frequency of invasive interventions.

RESULTS

In VKA-ICH 33.5% (670/2001), in NOAC-ICH 44.2% (69/156) and in non-OAC-ICH 25.2% (254/1009) of the patients were ≥80 years. After adjustment for treatment interventions and relevant parameters, elderly ICH patients comprised worse functional outcome at three months (adjusted odds ratio (aOR) in VKA-ICH: 1.49 (1.21-1.84); p < 0.001; NOAC-ICH: 2.01 (0.95-4.26); p = 0.069; non-OAC-ICH: 3.54 (2.50-5.03); p < 0.001). Anticoagulation was significantly associated with worse functional outcome below the age of 70 years, (aOR: 2.38 (1.78-3.16); p < 0.001), but not in patients of ≥70 years (aOR: 1.21 (0.89-1.65); p = 0.217). The differences in initial ICH volume and extent of ICH enlargement between OAC-ICH and non-OAC-ICH gradually decreased with increasing patient age.

CONCLUSIONS

As compared to elderly ICH-patients, in patients <70 years OAC-ICH showed worse clinical outcomes compared to non-OAC-ICH because of larger baseline ICH-volumes and extent of hematoma enlargement. Treatment strategies aiming at neutralizing altered coagulation should be aware of these findings.

Low Bone-Mineral Density Is a Significant Risk for Proximal Junctional Failure After Surgical Correction of Adult Spinal Deformity: A Propensity Score-Matched Analysis

STUDY DESIGN

A propensity-matched comparison of risk factors for proximal junctional failure (PJF), which is a symptomatic proximal junctional kyphosis developing after corrective surgery for adult spinal deformity (ASD).

OBJECTIVE

To elucidate the role of bone strength for developing PJF.

SUMMARY OF BACKGROUND DATA

PJF, a devastating complication of corrective surgery for ASD, often recurs even after revision surgery. Most studies of risk factors for PJF are retrospective and have a selection bias in surgical strategy, making it difficult to identify modifiable PJF risk factors.

METHODS

We conducted propensity-matched comparisons of 113 surgically treated ASD patients who were followed for at least 2 years, to elucidate whether low bone-mineral density (BMD) was a true risk factor for PJF in a uniform population from a multicenter database. Patients were grouped as having mildly low to normal BMD (M group; T-score≧ - 1.5) or significantly low BMD (S group; T-score <  -1.5), and were propensity-matched for age, upper and lower instrumented vertebrae, history of spine surgery, and Schwab-Scoliosis Research Society (SRS) ASD classification. PJF was defined as a ≥20° increase from the baseline proximal junction angle with a concomitant deterioration of at least one SRS-Schwab sagittal modifier grade, or any type of proximal junctional kyphosis requiring revision.

RESULTS

PJF developed in 22 of 113 patients (19%). There were 48 propensity-matched patients in the M and S groups (24 in each) with similar parameters for age, body mass index, number of vertebrae involved, C7SVA, pelvic incidence  - LL, and SRS-Schwab type. In this propensity-matched population, the incidence of PJF was significantly higher in the S group (33% vs. 8%, P < 0.01, odds ratio 6.4, 95% CI: 1.2-32.3).

CONCLUSION

Low BMD was a significant risk factor for PJF in this propensity-matched cohort (odds ratio 6.4). Surgeons should consider prophylactic treatments when correcting ASD in patients with low BMD.

LEVEL OF EVIDENCE

3.

Presence of Concomitant Systemic Cancer is Not Associated with Worse Functional Long-Term Outcome in Patients with Intracerebral Hemorrhage

BACKGROUND

Data on clinical characteristics and outcome of patients with intracerebral hemorrhage (ICH) and concomitant systemic cancer disease are very limited.

METHODS

Nine hundred and seventy three consecutive primary ICH patients were analyzed using our prospective institutional registry over a period of 9 years (2006-2014). We compared clinical and radiological parameters as well as outcome - scored using the modified Rankin Scale (mRS) and analyzed in a dichotomized fashion as favorable outcome (mRS = 0-3) and unfavorable outcome (mRS = 4-6) - of ICH patients with and without cancer. Relevant imbalances in baseline clinical and radiological characteristics were adjusted using propensity score (PS) matching.

RESULTS

Prevalence of systemic cancer among patients with ICH was 8.5% (83/973). ICH patients with cancer were older (77 [70-82] vs. 72 [63-80] years; p = 0.002), had more often prior renal dysfunction (19/83 [22.9%] vs.107/890 [12.0%]; p = 0.005), and smaller hemorrhage volumes (10.1 [4.8-24.3] vs. 15.3 [5.4-42.9] mL; p = 0.017). After PS-matching there were no significant differences neither in mortality nor in functional outcome both at 3 months (mortality: 33/81 [40.7%] vs. 55/158 [34.8%]; p = 0.368; mRS = 0-3: 28/81 [34.6%] vs. 52/158 [32.9%]; p = 0.797) and 12 months (mortality: 39/78 [50.0%] vs. 70/150 [46.7%]; p = 0.633; mRS = 0-3: 25/78 [32.1%] vs. 53/150 [35.3%]; p = 0.620) among patients with and without concomitant systemic cancer. ICH volume tended to be highest in patients with hematooncologic malignancy and smallest in urothelial cancer.

CONCLUSIONS

Patients with ICH and concomitant systemic cancer on average are older; however, they show smaller ICH volumes compared to patients without cancer. Yet, mortality and functional outcome is not different in ICH patients with and without cancer. Thus, the clinical history or the de novo diagnosis of concomitant malignancies in ICH patients should not lead to unjustified treatment restrictions.

Type of incision does not predict abdominal wall outcome after emergency surgery for colonic anastomotic leakage

PURPOSE

Most literature on abdominal incision is based on patients undergoing elective surgery. In a cohort of patients with anastomotic leakage after colonic cancer resection, we analyzed the association between type of incision, fascial dehiscence, and incisional hernia.

METHODS

Data were extracted from the Danish Colorectal Cancer Group database and merged with information from the Danish National Patient Register. All patients with anastomotic leakage after colonic resection in Denmark from 2001 until 2008 were included and surgical records on re-operations were retrieved. The primary outcome of the study was incisional hernia formation, and the secondary outcome was fascial dehiscence. Multivariable logistic, Cox, and competing risks regression analysis, as well as propensity score matching were used for confounder control.

RESULTS

A total of 363 patients undergoing reoperation for anastomotic leakage were included with a median follow-up of 5.4 years. Incisional hernia occurred in 41 of 227 (15.3%) patients undergoing midline incision compared with 14 of 81 (14.7%) following transverse incision, P = 1.00. After adjusting for confounders, there was no association between the type of incision and incisional hernia (transverse incision hazard ratio 1.36, 0.68-2.72, P = 0.390) or fascial dehiscence (transverse incision odds ratio 1.66, 0.57-4.49, P = 0.331). This conclusion was confirmed after propensity score matching, P = 0.507.

CONCLUSIONS

In the current study, type of incision did not predict abdominal wall outcome after emergency surgery for colonic anastomotic leakage.

Identifying independent risk factors for graft loss after primary liver transplantation

PURPOSE

The aim of the study is the identification of independent risk factors for re-transplantation after primary liver transplantation beyond the occurrence of hepatic artery thrombosis.

METHODS

Eight hundred thirty-four adult patients undergoing primary liver transplantation were analyzed. A propensity score was developed using multivariable binary logistic regression with hepatic artery thrombosis as the dependent variable. The logit link function of the propensity score was included into multivariable Cox regression analysis for graft survival to adjust the study population.

RESULTS

Graft loss was observed in 134 patients (16.1%). Independent significant risk factors for graft loss were recipient platelet count (p = 0.040; HR: 1.002; 95%-CI: 1.000-1.003), preoperative portal vein thrombosis (p = 0.032; HR: 1.797; 95%-CI: 1.054-2.925), donor age (p < 0.001; HR: 1.026; 95%-CI: 1.012-1.040), percentage of macrovesicular steatosis of the graft (p = 0.011; HR: 1.037; 95%-CI: 1.009-1.061), early complications leading to revision surgery (p < 0.001; HR: 2.734; 95%-CI: 1.897-3.956), duration of the transplant procedure (p < 0.001; HR: 1.005; 95%-CI: 1.003-1.007) as well as transplantation of a split liver graft (p = 0.003; HR: 2.637; 95%-CI: 1.420-4.728). The logit of the propensity score did not reach statistical significance in the final multivariable Cox regression model (p = 0.111) indicating good adjustment for the occurrence of hepatic artery thrombosis.

CONCLUSION

Liver transplant programs might benefit from regular donor organ biopsies to assess the amount of macrovesicular steatosis. An elevated recipient platelet count can promote reperfusion injury leading to graft loss. A liver graft from an elderly donor should not be split or be transplanted in a recipient with detected portal vein thrombosis.

Surgical Outcomes for the Ruptured Hepatocellular Carcinoma: Multicenter Analysis with a Case-Controlled Study

BACKGROUND

While spontaneously ruptured hepatocellular carcinoma (HCC) has a poor prognosis, the true impact of a rupture on survival after hepatic resection is unclear.

METHODS

Fifty-eight patients with ruptured HCC and 1922 with non-ruptured HCC underwent hepatic resection between 2000 and 2013. To correct the difference in the clinicopathological factors between the two groups, propensity score matching (PSM) was used at a 1:1 ratio, resulting in a comparison of 42 patients/group. We investigated outcomes in all patients with ruptured HCC and compared outcomes between the two matched groups.

RESULTS

Of the 58 patients with ruptured HCC, 7 patients (13 %) died postoperatively. Overall survival (OS) rate at 5 years after hepatic resection was 37 %. Emergency hepatic resection was an independent risk factor for in-hospital death and Child-Pugh class B for unfavorable OS in multivariate analysis. Clinicopathological variables were well-balanced between the two groups after PSM. No significant differences were noted in incidence of in-hospital death (ruptured HCC 12 % vs non-ruptured HCC 2 %, p = 0.202) or OS rate (5/10-year; 42 %/38 % vs 67 %/30 %, p = 0.115).

CONCLUSION

Emergency hepatic resection should be avoided for ruptured HCC in Child-Pugh class B patients. Rupture itself was not a risk for unfavorable surgical outcomes.

Impact of Adjuvant Chemotherapy on Breast Cancer Survival: A Real-World Population

Background

The impact of adjuvant chemotherapy on breast cancer prognosis has been demonstrated in randomized trials, but its impact is unknown in real-world populations. The aim of this study was to evaluate the effect of adjuvant chemotherapy on the survival of breast cancer patients in an unselected population.

Methods

This prospective cohort study included 32,502 women treated at the Institut Curie between 1981 and 2008 for a first invasive breast cancer without metastasis. The patients were matched based on their propensity score to receive adjuvant chemotherapy.

Results

The matching generated a subsample of 9,180 patients with an overlapping propensity score. In the group without chemotherapy, the overall survival (OS) rates at 5 and 10 years of follow-up were 87.6% (95% CI [86.7–88.6]) and 75.0% (95% CI [73.6–76.5]), respectively, versus 92.1% (95% CI [91.3–92.9]) and 81.9% (95% CI [80.6–83.2]), respectively, in the chemotherapy group. Distant disease-free survival (DDFS) was significantly improved in the five first years (absolute benefit of 3.5%). In a multivariate analysis, adjuvant chemotherapy was associated with better OS (HR = 0.75, 95% CI [0.69–0.83], p<0.0001) and DDFS (HR = 0.82, 95% CI [0.75–0.90], p<0.0001).

Conclusion

Adjuvant chemotherapy significantly improves OS and DDFS rates in an unselected population, in accordance with previous results reported by randomized trials.

Prognostic effect of erroneous surgical procedures in patients with osteosarcoma: evaluation using propensity score matching

BACKGROUND

Little is known concerning erroneous surgical procedures of malignant bone tumors, and the prognostic effect of erroneous surgical procedures in osteosarcoma has not been determined.

METHODS

We retrospectively reviewed 240 patients with initially non-metastatic high-grade osteosarcoma of the pelvis and extremities and, of these, identified twenty-six who had undergone previous less appropriate surgical procedures due to misdiagnosis followed by adequate treatment at our institution. We evaluated the clinicopathologic characteristics of these twenty-six patients compared with the remaining 214 patients treated with regular protocol. Subsequently, thirty-eight patients (nineteen in the matched case group and nineteen in the matched control group) were matched for multiple different variables using propensity score matching, and the oncologic results in terms of event-free survival and overall survival were analyzed.

RESULTS

The patients undergoing erroneous surgical procedures were typically older, with small, non-osteoblastic-type tumors that were in an unusual location, showed an osteolytic pattern on radiographs, had a tendency toward marginal or intralesional excision with positive histologic margin, and had not been treated with neoadjuvant chemotherapy (all p < 0.05). After adjustment of confounding variables by propensity score matching, there was no significant difference between matched groups with regard to event-free survival (p = 0.46) and overall survival (p = 0.99).

CONCLUSIONS

Distinct differences existed in the clinicopathologic characteristics of the patients who underwent erroneous surgical procedures due to misdiagnosis. We failed to detect a prognostic relevance of the presence of previous erroneous procedures followed by adequate treatment.

Evaluation of the effect of a comprehensive multidisciplinary care pathway for hip fractures: design of a controlled study

Background

Hip fractures constitute an economic burden on healthcare resources. Most persons with a hip fracture undergo surgery. As morbidity and mortality rates are high, perioperative care leaves room for improvement. Improvement can be achieved if it is organized in comprehensive care pathways, but the effectiveness of these pathways is not yet clear. Hence the objective of this study is to compare the clinical effectiveness of a comprehensive care pathway with care as usual on self-reported limitations in Activities of Daily Living.

Methods/Design

A controlled trial will be conducted in which the comprehensive care pathway of University Medical Center Groningen will be compared with care as usual in two other, nonacademic, hospitals. In this trial, propensity scores will be used to adjust for differences at baseline between the intervention and control group. Propensity scores can be used in intervention studies where a classical randomized controlled trial is not feasible. Patients aged 60 years and older will be included. The hypothesis is that 15% more patients at University Medical Center Groningen compared with patients in the care-as-usual condition will have recovered at least as well at 6 months follow-up to pre-fracture levels for Activities of Daily Living.

Discussion

This study will yield new knowledge with respect to the clinical effectiveness of a comprehensive care pathway for the treatment of hip fractures. This is relevant because of the growing incidence of hip fractures and the consequent massive burden on the healthcare system. Additionally, this study will contribute to the growing knowledge of the application of propensity scores, a relatively novel statistical technique to simulate a randomized controlled trial in studies where it is not possible or difficult to execute this kind of design.

Trial registration

Nederlands Trial Register NTR3171

Generating new knowledge in cardiac interventions

Cardiac interventions are among the most quantitatively studied therapies. It is important for all involved with cardiac interventions to understand how information generated from observations made during patient care is transformed into data suitable for analysis, to appreciate at a high level what constitutes appropriate analyses of those data, to effectively evaluate inferences drawn from those analyses, and to apply new knowledge to better care for individual patients.

Statin therapy is associated with fewer infections after cardiac operations

BACKGROUND

Statins interact with multiple pathways involved in infection. Therefore, we examined the association between preoperative statin therapy and infections after cardiac operations and assessed whether statin therapy was associated with lower infection-related mortality.

METHODS

From January 2005 to January 2011, 12,741 patients underwent cardiac operations. Endpoints were (1) postoperative infections and (2) mortality after an infectious complication. A propensity score was developed on the probability of patients receiving statin therapy; patients were matched in part on this score. A multivariable logistic model was developed to examine mortality. Survival of infected patients was estimated using Kaplan-Meier and multiphase hazard function methodology.

RESULTS

A total of 6,113 patients (48%) were receiving statins and 6,628 (52%) were not. Five hundred fifteen patients had postoperative infections-260 (4.3%) in the statin group and 255 (3.8%) in the no-statin group. However, patients receiving statins were older with more comorbidities and less favorable operative characteristics. Among propensity-matched groups, postoperative infections were significantly lower in patients receiving statins (n = 102 [3.1%]) than in those who were not (n = 147 [4.5%]; p = 0.004). Among patients in whom infections developed, there was no significant difference in hospital mortality between the statin and no-statin groups either before or after propensity-score matching (odds ratio, 1.38; confidence limit [CL], 0.59, 3.22; p = 0.5).

CONCLUSIONS

We observed a protective effect of statin therapy against the development of infections after cardiac operations, but not on mortality from these infections. Prospective investigations are needed to determine optimal dose and duration of statin therapy and their relationship to infectious complications.

Effectiveness of diabetes and hypertension management by rural primary health-care workers (Behvarz workers) in Iran: a nationally representative observational study

BACKGROUND

Non-communicable diseases and their risk factors are leading causes of disease burden in Iran and other middle-income countries. Little evidence exists for whether the primary health-care system can effectively manage non-communicable diseases and risk factors at the population level. Our aim was to examine the effectiveness of the Iranian rural primary health-care system (the Behvarz system) in the management of diabetes and hypertension, and to assess whether the effects depend on the number of health-care workers in the community.

METHODS

We used individual-level data from the 2005 Non-Communicable Disease Surveillance Survey (NCDSS) for fasting plasma glucose (FPG) and systolic blood pressure (SBP), body-mass index, medication use, and sociodemographic variables. Data for Behvarz-worker and physician densities were from the 2006 Population and Housing Census and the 2005 Outpatient Care Centre Mapping Survey. We assessed the effectiveness of treatment on FPG and SBP, and associations between FPG or SBP and Behvarz-worker density with two statistical approaches: a mixed-effects regression analysis of the full NCDSS sample adjusting for individual-level and community-level covariates and an analysis that estimated average treatment effect on data balanced with propensity score matching.

RESULTS

NCDSS had data for 65,619 individuals aged 25 years or older (11,686 of whom in rural areas); of these, 64,694 (11,521 in rural areas) had data for SBP and 50,202 (9337 in rural areas) had data for FPG. Nationally, 39·2% (95% CI 37·7 to 40·7) of individuals with diabetes and 35·7% (34·9 to 36·5) of those with hypertension received treatment, with higher treatment coverage in women than in men and in urban areas than in rural areas. Treatment lowered mean FPG by an estimated 1·34 mmol/L (0·58 to 2·10) in rural areas and 0·21 mmol/L (-0·15 to 0·56) in urban areas. Individuals in urban areas with hypertension who received treatment had 3·8 mm Hg (3·1 to 4·5) lower SBP than they would have had if they had not received treatment; the treatment effect was 2·5 mm Hg (1·1 to 3·9) lower FPG in rural areas. Each additional Behvarz worker per 1000 adults was associated with a 0·09 mmol/L (0·01 to 0·18) lower district-level average FPG (p=0·02); for SBP this effect was 0·53 mm Hg (-0·44 to 1·50; p=0·28). Our findings were not sensitive to the choice of statistical method.

INTERPRETATION

Primary care systems with trained community health-care workers and well established guidelines can be effective in non-communicable disease prevention and management. Iran's primary care system should expand the number and scope of its primary health-care worker programmes to also address blood pressure and to improve performance in areas with few primary care personnel.

FUNDING

None.

Interstitial pneumonia after autologous hematopoietic stem cell transplantation in B-cell non-hodgkin lymphoma

INTRODUCTION

During the past decade, interstitial pneumonia (IP) is one of the newly recognized adverse events regarding rituximab therapy. However, disease characteristics of IP after autologous hematopoietic stem cell transplantation (ASCT) have not been well-described since the introduction of rituximab.

PATIENTS AND METHODS

We retrospectively analyzed 103 patients with B-cell non-Hodgkin lymphoma undergoing ASCT. A propensity scoring system was applied in our analysis to eliminate potential confounding factors of covariates.

RESULTS

The total number of patients who developed IP was nine. Five patients developed IP among 57 patients previously treated with rituximab, and four patients developed IP among 46 who were rituximab-naïve. Cumulative incidence of IP was 7.8% at 1 year. Among the patients using rituximab, one patient had IP during the peri-engraftment period (cytomegalovirus infection), three patients had IP between 3 and 12 months (Pneumocystis pneumonia [PCP, n = 1] and unknown cause [n = 2]), and the other one patient had IP 3.3 years after ASCT (unknown cause). Four patients in the rituximab-naïve group developed IP between 3 and 12 months (PCP [n = 1] and unknown cause [n = 3]). All nine patients had symptomatic episodes before IP, three of which died of IP or secondary infections. Patients receiving a total body irradiation conditioning regimen had a higher risk of IP (odds ratio = 3.6, P < .001), whereas the incidence was not affected by rituximab usage (P = .85, Log-rank test).

CONCLUSION

This study shows that the rituximab usage was not identified as a risk factor of IP and that total body irradiation was the only independent risk factor for IP. Close monitoring is encouraged when symptomatic unexplained episodes are identified during follow-up examinations after ASCT.

Have we changed the outcome in membranous nephropathy? A propensity study on the role of immunosuppressive therapy

BACKGROUND AND OBJECTIVES

The long-term effect of immunosuppressive therapy (IS) on kidney survival in idiopathic membranous nephropathy (MGN) is debated. The introduction of renin angiotensin blockade, rigorous BP control, and the increasing age at presentation of patients with MGN adds further uncertainty. Given these important changes, we sought to determine whether implementation of IS has altered outcome.

DESIGN, SETTING, PARTICIPANTS, & METHODS

We prospectively evaluated 280 incident MGN patients from three distinct 10-year periods starting from 1975.

RESULTS

We found expected changes in treatment regimens but also variations in age, renal function, severity of proteinuria, and BP at presentation over this time. Outcomes did not differ over time if these significant variations in clinical characteristics were not accounted for across the eras. The effect of IS in the 57 patients treated with currently recommended regimens was assessed using propensity adjustment to address selection bias and the effect of newer, conservative therapies. A propensity score estimating the probability of receiving IS permitted the pairing of 39 treated patients with controls with similar high risk of progression of clinical features. Using this approach, IS was associated not only with remissions in proteinuria but also with substantially improved renal survival.

CONCLUSIONS

The study confirms that patient presenting characteristics and management regimens have changed significantly over time and the natural history of MGN has been altered. A study of propensity-matched patients confirms that current recommendations for IS have improved outcomes in MGN patients at high risk of progression.

The impact of postoperative intensive care on outcomes in elective neurosurgical patients in good physical condition: a single centre propensity case-matched study

PURPOSE

In the last three years, all elective neurosurgical cases were performed by a single surgeon at Nara Medical University. For the last year and a half, all patients were transferred to a newly created neurosurgical intensive care unit. The purpose of this study was to evaluate the impact of admission to an intensive care unit after elective neurosurgery.

METHODS

This study was conducted as a retrospective clinical chart review. Institutional ethics approval was waived, and we reviewed the charts of 296 neurosurgical patients who were American Society of Anesthesiologists' physical status I-II. To avoid channelling bias, propensity score analysis was used to generate a set of matched cases (patients transferred to the intensive care unit [ICU]) and controls (patients transferred to the neurosurgical ward). This process resulted in 104 matched pairs of elective surgical patients who did or did not have an ICU admission after surgery. Glasgow outcome scale (GOS) at discharge or at three months after the operation was compared as the primary outcome measure. As secondary outcome measures, we also compared rates of severe early complications and patient satisfaction regarding perioperative patient care.

RESULTS

With an unmatched population, poor GOS tended to occur more often in the non-ICU group than in the ICU group (6.5% vs 2.3%, respectively). Mortality rates and severe early complication rates also tended to be higher in the non-ICU group than in the ICU group (2.4% and 5.3%, respectively, non-ICU group vs 0.8% and 2.3%, respectively, ICU group). However, after propensity score matching, there was no difference regarding the GOS between groups. Both groups showed very high good outcome percentages (98.1% ICU vs 97.1% non-ICU). With regard to mortality rates and severe early complications, both groups showed low mortality (0.96% vs 0.96%) and complication rates (2.89% ICU vs 3.85% non-ICU). Patient care in the ICU failed to increase patient satisfaction regarding the overall hospital care.

CONCLUSION

The results of this analysis suggest that admission to an ICU after elective neurosurgery has little impact on outcomes.

An application of propensity score methods to estimate the treatment effect of corticosteroids in patients with severe cutaneous adverse reactions

PURPOSE

To investigate whether propensity score (ps) methods could reasonably be applied to estimate the treatment effect on mortality, based on a comparatively small sample of patients with severe cutaneous adverse reactions (SCAR) and who come from different countries where physicians prefer different treatment schemes.

METHODS

Ps methods were applied to cope with confounding due to non-randomized treatment assignment for the analysis of the treatment data obtained in the case-control study EuroSCAR. For the study's purpose, the analysis focused on the comparison of the treatments: corticosteroids (STER) and supportive care only (SUPP).

RESULTS

206 French and German patients were treated either with SUPP or STER. Imbalances between treatment groups as well as between the countries were recognized. Concerning the balance between the treatment groups no ps model for the full cohort was satisfying. In addition, the inclusion of a variable for patient's country led to a separation of the patients by country. Thus, we developed ps models for each country separately and estimated the treatment effects (France: odds ratio (OR) 0.52, 95% confidence interval (CI) 0.09-3.10, Germany: OR 0.23, CI 0.06-0.92, Overall: OR 0.33 CI 0.11-1.04).

CONCLUSIONS

The application of the ps methods was successful and provided valuable information. We could confirm the findings of the original analysis which was based on standard logistic regression, especially concerning the necessity of a country-specific analysis. The observed country differences in the estimated treatment effects were less pronounced and thus seemed to be more reasonable than those of the past analysis.

Decision support in surgical management of ischemic cardiomyopathy

OBJECTIVES

The surgical approach to ischemic cardiomyopathy maximizing survival remains a dilemma, with decisions complicated by secondary mitral regurgitation, ventricular remodeling, and heart failure. As a component of decision support, we sought to develop prediction models for comparing survival after coronary artery bypass grafting alone, coronary artery bypass grafting plus mitral valve anuloplasty, coronary artery bypass grafting plus surgical ventricular restoration, and listing for cardiac transplantation.

METHODS

From 1997 to 2007, 1468 patients with ischemic cardiomyopathy (ejection fraction <30%) underwent coronary artery bypass grafting alone (n = 386), coronary artery bypass grafting plus mitral valve anuloplasty (n = 212), coronary artery bypass grafting plus surgical ventricular restoration (n = 360), or listing for cardiac transplantation (n = 510). Mean follow-up was 3.8 +/- 2.8 years, with 5577 patient-years of data available for analysis. Risk factors were identified for early and late mortality by using 80% training and 20% validation sets. Outcomes were calculated for each applicable strategy to identify which maximized predicted 5-year survival. Models were programmed as a strategic decision-support tool.

RESULTS

One-, 5-, and 9-year survival were as follows, respectively: coronary artery bypass grafting, 92%, 72%, and 53%; coronary artery bypass grafting plus mitral valve anuloplasty, 88%, 57%, and 34%; coronary artery bypass grafting plus surgical ventricular restoration, 94%, 76%, and 55%; and listing for cardiac transplantation, 79%, 66%, and 54%. Risk factors included older age, higher New York Heart Association class, lower ejection fraction, longer interval from myocardial infarction to operation, and numerous comorbidities. Predicted and observed survivals in validation groups were similar (P > .1). Patient-specific simultaneous solutions of applicable models revealed therapy potentially providing maximum survival benefit. Coronary artery bypass grafting alone and listing for cardiac transplantation often maximized 5-year survival; only 15% of patients undergoing coronary artery bypass grafting plus mitral valve anuloplasty were predicted to fare best with this therapy.

CONCLUSION

Validated prediction models can aid surgeons in recommending personalized treatment plans that maximize short- and long-term survival for ischemic cardiomyopathy.

Epidemiological studies of the non-specific effects of vaccines: II--methodological issues in the design and analysis of cohort studies

We review sources of bias which can affect non-randomized cohort studies of non-specific effects of vaccines on child mortality. Using examples from the literature on non-specific effects, we describe different sources of selection and information bias, and, where possible, outline analysis strategies to mitigate or eliminate such biases.

Health care costs in the last week of life: associations with end-of-life conversations

BACKGROUND

Life-sustaining medical care of patients with advanced cancer at the end of life (EOL) is costly. Patient-physician discussions about EOL wishes are associated with lower rates of intensive interventions.

METHODS

Funded by the National Institute of Mental Health and the National Cancer Institute, Coping With Cancer is a longitudinal multi-institutional study of 627 patients with advanced cancer. Patients were interviewed at baseline and were followed up through death. Costs for intensive care unit and hospital stays, hospice care, and life-sustaining procedures (eg, mechanical ventilator use and resuscitation) received in the last week of life were aggregated. Generalized linear models were applied to test for cost differences in EOL care. Propensity score matching was used to reduce selection biases.

RESULTS

Of 603 participants, 188 (31.2%) reported EOL discussions at baseline. After propensity score matching, the remaining 415 patients did not differ in sociodemographic characteristics, recruitment sites, illness acknowledgment, or treatment preferences. Further analyses, adjusted by quintiles of propensity scores and significant confounders, revealed that the mean (SE) aggregate costs of care (in 2008 US dollars) were $1876 ($177) for patients who reported EOL discussions compared with $2917 ($285) for patients who did not, a cost difference of $1041 (35.7% lower among patients who reported EOL discussions) (P =.002). Patients with higher costs had worse quality of death in their final week (Pearson production moment correlation partial r = -0.17, P =.006).

CONCLUSIONS

Patients with advanced cancer who reported having EOL conversations with physicians had significantly lower health care costs in their final week of life. Higher costs were associated with worse quality of death.

Breastfeeding, body mass index, asthma and atopy in children

The objective of this study was to determine the relationship between breastfeeding, asthma and atopy, and any influence of child body mass index (BMI). Prospective birth cohort data were used to model the association between breastfeeding duration, BMI, asthma and atopy in children at six years. After adjustment for BMI and associated covariates, breastfeeding (per additional month of feeding) was marginally associated with decreased BMI (p=0.083). BMI was significantly associated with current asthma (p=<0.0005) and atopy (p=0.055). Exclusive breastfeeding for less than four months was a risk for current asthma (p=0.033) and atopy (p=0.005). The early introduction of formula leads to an increase in child BMI and early asthma and atopy. Increased BMI is a risk factor for childhood asthma and atopy. These findings suggest that public health interventions to optimise breastfeeding duration and reduce overweight in children may help attenuate the community burden of wheezing illness early in life.

Selection bias in evaluating of influenza vaccine effectiveness: a lesson from an observational study of elderly nursing home residents

Selection bias is of critical concern in the study of influenza vaccine effectiveness when using an observational study design. This bias is attributable to the inherently different characteristics between vaccinees and non-vaccinees. The differences, which are related both to vaccination and signs of clinical disease as an outcome, may lead to erroneous estimation of the effectiveness. In this report, we describe how selection bias among elderly nursing home residents may lead to a spurious interpretation of the protective effect of influenza vaccine. Our results should be a lesson in the importance of regarding selection bias when assessing influenza vaccine effectiveness.

Effect of an academic detailing intervention on the utilization rate of cyclooxygenase-2 inhibitors in the elderly

BACKGROUND

Osteoarthritis is prevalent in the elderly. Nova Scotia general practitioners (GPs) identified the need for an academic detailing (AD) intervention aimed at optimizing the management of osteoarthritis. AD was provided by Dalhousie University Continuing Medical Education in a face-to-face encounter employing evidence-based information. GP participation was voluntary.

OBJECTIVE

To evaluate the effect of a GP-targeted osteoarthritis AD intervention on a reduction in the prescribing of cyclooxygenase-2 (COX-2) inhibitors, as well as examine the intervention effect on the utilization rates of gastroprotective agents and medical services.

METHODS

A retrospective cohort study design employing administrative data was used. Differences in utilization rates between intervention and control groups were evaluated using generalized estimating equations analysis for longitudinal data over four 90-day postintervention periods. Confounding was addressed using propensity scores to adjust for between-group bias on the measured covariates.

RESULTS

The between-group difference for change in COX-2 utilization rates was 0.76 defined daily doses/patient (p = 0.040; 95% CI 0.037 to 1.48) for the 3-month period following the intervention, with lower COX-2 utilization in the AD intervention group than in the control group. The intervention group showed a significant decrease in the within-group utilization rate between the pre- and postintervention periods (z =-2.34; p = 0.019). The between-group difference for change in GP office visit rates was 0.40 visits/patient (p = 0.028; 95% CI 0.046 to 0.79) with the intervention group, showing higher visit rates compared with the control group.

CONCLUSIONS

The osteoarthritis AD intervention was associated with a significant decrease (23%) in COX-2 utilization rates in the 3-month period immediately following the intervention. The only secondary outcome to show a significant between-group effect was the GP office visit rate, which was higher for the intervention group in the second 3-month postintervention period.

Survival among COPD patients using fluticasone/salmeterol in combination versus other inhaled steroids and bronchodilators alone

Recent retrospective studies have suggested that use of inhaled corticosteroids (ICS) may improve survival in chronic obstructive pulmonary disease (COPD), particularly when combined with a long-acting beta-agonist (LABA). However, the study methodologies have been questioned, and no study has examined the survival effect of the newer combination ICS/LABA inhalers. The goal of this project was to further examine the relationship between ICS treatment, with or without LABA, and survival in COPD. COPD patients were identified from the administrative databases of four different integrated health care delivery systems. All patients who were diagnosed with COPD between September 1, 2000 and August 31, 2001 and who had at least 3 months treatment with either a combined fluticasone/salmeterol inhaler (FSI, N=866), any ICS used with a LABA (ICS/LABA, N=525), ICS alone (N=742), LABA alone (N=531), or a short-acting bronchodilator alone (SABD, N=1832), were included. Analyses were conducted using three different analysis approaches that adjust for various biases that may affect the results. In the basic Cox proportional hazards models, use of FSI, ICS/LABA, ICS alone, and LABA alone had significant survival benefits as compared to SABD, after adjustment for differences in age, gender, comorbidities, asthma status, and disease severity (HRs 0.61 [0.45-0.83], 0.59 [0.46-0.77], 0.76 [0.61-0.95], 0.75 [0.57-0.98], respectively). Propensity score matching to reduce the clinical differences between the treatment groups versus the SABD reference group found very similar results. Nested case-control analyses, which are based on survival status instead of treatment, continued to show a significant survival benefit for FSI, ICS/LABA, and ICS alone. Treatment with FSI or another ICS with or without LABA is associated with improved survival in COPD. The treatment benefit is reproducible and is robust to application of a number of different analysis techniques designed to adjust for differences in confounding variables and for bias by indication.

The direct and indirect cost burden of clinically significant and symptomatic uterine fibroids

OBJECTIVE

To estimate direct medical costs and indirect (productivity related) for women age 25 to 54 who had clinically significant and symptomatic uterine fibroids (UF).

METHODS

We compared direct medical expenditures among 30,659 women who had clinically significant and symptomatic UF to expenditures among an equal number of matched controls who did not. We also compared indirect costs for a sub-sample of 910 employed women in each group. Regression analyses controlled for demographic and casemix factors.

RESULTS

Mean 12-month direct medical costs for women with UF were $11,720 versus $3257 for controls, and mean 12-month indirect costs for women with UF were $11,752 versus $8083 for controls. Differences were statistically significant (P<0.0001).

CONCLUSIONS

UF is a costly disorder and merits thought as interventions are considered to improve women's health and productivity.

No evidence that early use of inhaled corticosteroids reduces current asthma at 10 years of age

BACKGROUND

It is debated whether early treatment with inhaled corticosteroids (ICS) can change the natural course of childhood asthma.

AIM

To assess if ICS treatment before 2 years of age in children with obstructive airways disease reduces current asthma at 10 years of age.

METHODS

Children with (n=233) and without (n=219) recurrent (r) bronchial obstruction (BO) attending clinical examination at 2 years of age in the birth cohort Environment and Childhood Asthma study in Oslo, were reinvestigated at 10 years of age. Current asthma (CA) at 10 years was defined as asthma with either symptoms and/or asthma treatment during the last year, and/or 10% fall in forced expired volume in 1s after standardized treadmill run. The risk of CA was assessed by logistic regression and propensity modelling (including gender, parental atopy and severity score at 2 years) in children with rBO who received ICS or not by 2 years.

RESULTS

CA was found in 97 children, more often among rBO children with (56.9%) and without ICS treatment (30.8%) compared to no-BO children (5.5%) (p<0.001). In rBO children logistic regression analyses (adjusted odds ratio aOR (95% confidence interval)) identified male gender (aOR 1.82 (1.01-3.27), p=0.046) and severity score at 2 years 1.14 (1.03-1.28), (p=0.01), as significant and ICS treatment as non-significant 2.00 (0.98-4.12) risk factors for CA. With propensity modelling adjusting for disease severity, ICS treatment by 2 years caused a non-significant increased risk aOR of CA of 1.84 (0.89-3.82).

CONCLUSION

No evidence was found that early use of ICS before age two in children with rBO reduces current asthma 8 years later.

Impact of mitral valve annuloplasty combined with revascularization in patients with functional ischemic mitral regurgitation

OBJECTIVES

The aim of this work was to determine whether mitral valve (MV) annuloplasty benefits patients with moderate/severe (3+/4+) functional ischemic mitral regurgitation (MR) who undergo coronary artery bypass grafting (CABG).

BACKGROUND

Mitral regurgitation is a strong predictor of poor outcomes in patients with ischemic cardiomyopathy; whether correcting it at the time of CABG improves outcomes is less certain.

METHODS

From 1991 to 2003, 390 patients with 3+/4+ ischemic MR had CABG with (n = 290) or without (n = 100) MV annuloplasty. Groups were propensity-matched using demographics, extent of coronary disease, regional wall motion, and quantitative electrocardiography. Survival, echocardiographic severity of MR, and New York Heart Association (NYHA) functional class were compared.

RESULTS

One-, 5-, and 10-year survival was 88%, 75%, and 47% after CABG alone and 92%, 74%, and 39% after CABG + MV annuloplasty (p = 0.6). Mortality was increased in patients with severe lateral wall motion abnormalities (p = 0.05), ST-segment elevation in lateral leads (p < 0.004), and higher QRS voltage sum (p < 0.0001). Patients undergoing CABG alone were more likely to have 3+/4+ postoperative MR than those undergoing CABG + MV annuloplasty (48% vs. 12% at 1 year, p < 0.0001). The NYHA functional class substantially improved in both groups (p < 0.001) and remained improved; at 5 years, 23% of patients having CABG + mitral annuloplasty and 25% having CABG alone were in NYHA functional class III/IV.

CONCLUSIONS

Although CABG + MV annuloplasty reduces postoperative MR and improves early symptoms compared with CABG alone, it does not improve long-term functional status or survival in patients with severe functional ischemic MR. The MV annuloplasty in this setting, without addressing fundamental ventricular pathology, is insufficient to improve long-term clinical outcomes.

Improved Outcomes After Aortic Valve Surgery for Chronic Aortic Regurgitation With Severe Left Ventricular Dysfunction

OBJECTIVES

Among patients undergoing aortic valve surgery for chronic aortic regurgitation (AR), we sought to: 1) compare survival among those with and without severe left ventricular dysfunction (LVD); 2) identify risk factors for death, including LVD and date of operation; and 3) estimate contemporary risk for cardiomyopathic patients.

BACKGROUND

Patients with chronic AR and severe LVD have been considered high risk for aortic valve surgery, with limited prognosis. Transplantation is considered for some.

METHODS

From 1972 to 1999, 724 patients underwent surgery for chronic AR; 88 (12%) had severe LVD. They were propensity matched to patients with nonsevere LVD to compare hospital mortality, interaction of operative date with severity of LVD, and late survival. Propensity score-adjusted multivariable analysis was performed for all 724 patients to identify risk factors for death.

RESULTS

Survival was lower (p = 0.04) among patients with severe LVD than among matched patients with nonsevere LVD (30-day, 1-, 5-, and 25-year survival estimates were 91% vs. 96%, 81% vs. 92%, 68% vs. 81%, and 5% vs. 12%, respectively). However, survival of patients with severe LVD improved dramatically across the study time frame (p = 0.0004): hospital mortality decreased from 50% in 1975 to 0% after 1985, and time-related survival in patients with severe LVD operated on since 1985 became equivalent to that of matched patients with nonsevere LVD (p = 0.96).

CONCLUSIONS

Neutralizing risk of severe LVD has improved early and late survival such that aortic valve surgery for chronic AR and cardiomyopathy is no longer a high-risk procedure for which transplantation is the best option.

Recent Metformin Ingestion Does Not Increase In-Hospital Morbidity or Mortality After Cardiac Surgery

BACKGROUND

Perioperative treatment of type 2 diabetes with metformin, an oral hypoglycemic drug, is thought to increase the risk of life-threatening postoperative lactic acidosis. In contrast, metformin improves serum glucose control and has beneficial cardiovascular effects, which may decrease the risk of adverse outcomes. In this investigation we sought to determine the influence of metformin treatment on mortality and morbidity compared with treatment with other oral hypoglycemic drugs in diabetic patients undergoing cardiac surgery.

METHODS

In this retrospective investigation, 1284 diabetic patients, with recent oral hypoglycemic ingestion (presumed to be 8-24 h preoperatively), underwent cardiac surgery from 1994-2004. Propensity scores were calculated from a logistic model which included baseline characteristics and perioperative variables. Four-hundred-forty-three (85%) of the metformin-treated patients were matched on nearest propensity score using greedy matching techniques with 443 nonmetformin-treated patients. Postoperative outcomes were compared between matched metformin- and nonmetformin-treated patients.

RESULTS

In-hospital mortality, cardiac, renal, and neurologic morbidities were similar between groups. Metformin-treated patients had less postoperative prolonged tracheal intubation [OR (95% CI), 0.3 (0.1, 0.7), P = 0.003], infection [0.2 (0.1, 0.7), P = 0.007] and overall morbidities [0.4 (0.2, 0.8), P = 0.005].

CONCLUSIONS

These data suggest that recent metformin ingestion is not associated with increased risk of adverse outcome in cardiac surgical patients. Alternatively, metformin treatment may have beneficial effects.

The impact of gender on in-hospital mortality and morbidity after isolated aortic valve replacement

The objective of our retrospective investigation was to examine the influence of gender on in-hospital mortality and morbidity after isolated aortic valve replacement (AVR). Between January 1993 and June 2002, 2212 patients (782 females, 1430 males) underwent AVR. Propensity matching was used to adjust for numerous differences in baseline characteristics and perioperative variables between groups. Unadjusted in-hospital mortality was higher in females (27 [3.5%] females versus 23 [1.6%] males; P = 0.005). An analysis using 1:1 matching by propensity score did not find a significant difference in in-hospital mortality [OR (95% confidence intervals), 1.0 [0.4, 2.6]; P = 0.99) or overall morbidity (1.4 [0.7, 2.5]; P = 0.29) between groups. Further analyses, including classification of women and men into quintile groups by propensity scores and logistic regression models with propensity score adjustment, found that females were at increased risk for cardiac morbidity [OR (95% CI), 3.4 [1.1, 10.8]; P = 0.038), but not mortality (0.9 [0.3, 2.5]; P = 0.88) nor other morbidities. These results suggest that there is no greater than a 2.5-fold increase in risk for females compared with males undergoing AVR. Female gender, however, may impart increased risk for cardiac morbidity after AVR.

The impact of rheumatoid arthritis on medical expenditures, absenteeism, and short-term disability benefits

OBJECTIVES

The objectives of this study were to estimate medical expenditures, absenteeism, and short-term disability costs for workers with rheumatoid arthritis (RA) and to estimate the relative costs of RA over a 12-month period.

METHODS

Using data from nine U.S. employers, direct and indirect costs for 8502 workers with RA were compared with costs for a matched group without RA. Regression analyses controlled for factors that were different even after propensity score matching.

RESULTS

Average total costs for workers with RA were $4244 (2003 dollars) greater than for workers without RA. RA was the fourth most costly chronic condition per employee compared with cancers, asthma, bipolar disorder, chronic obstructive pulmonary disease, depression, diabetes, heart disease, hypertension, low back disorders, and renal failure.

CONCLUSIONS

RA is a costly disorder and merits consideration as interventions are considered to improve workers' health and productivity.