Overall conceptual framework for studying the genetics of autoimmune diseases following vaccination: a regulatory perspective

The US Vaccine Adverse Event Reporting System contains case reports of autoimmune diseases (ADs) occurring following vaccinations. ADs are rare and occur in unvaccinated people, making the potential association between vaccines and ADs challenging to evaluate. Developing mechanistic pathways that link genes, immune mediators, vaccine components and ADs would be helpful for hypothesis generation, enhancing theories of biologic plausibility and grouping rare autoimmune adverse events to increase the ability to detect and evaluate safety signals. Here, we propose a conceptual framework for investigating the genetics of ADs as safety signals following vaccination, potentially contributing to the identification of relevant biomarkers. We also discuss a study design that incorporates genetic information into postmarket clinical evaluation of autoimmune adverse events following vaccination.

Implementation of clinical practice guidelines for prevention of thromboembolism in spinal cord injury

BACKGROUND/OBJECTIVES

The purpose of this study was to determine whether publication of the "Prevention of Thromboembolism in Spinal Cord Injury" clinical practice guideline (CPG) changed patient management and whether adherence to CPG recommendations improved after a targeted implementation strategy.

METHODS

Data were abstracted from medical records of 134 and 520 patients with acute and chronic spinal cord injury (SCI), respectively, from 6 Veterans Affairs medical centers over 3 time periods: prepublication (T1), preimplementation (T2), and postimplementation (T3) of the CPG. Targeted interventions were developed to address provider-perceived barriers to guideline adherence, based on findings from focus groups conducted at each site. The interventions incorporated two implementation strategies: standardized documentation templates/standing orders and social marketing/outreach visits.

RESULTS

Use of the specified duration for pharmacologic prophylaxis increased from 60% to 65% to 75% of patients with acute SCI in T1, T2, and T3, respectively (P = 0.060 and 0.041 for T1 vs T2 and T2 vs T3, respectively). Rates of use for individual pharmacologic prophylaxis agents changed significantly over the course of the study, with use of low-molecular-weight heparin increasing from 7% in T1 to 42% in T3. Physical assessments for thrombosis on hospitalization days 1 and 30 improved between T2 and T3. Use of prophylaxis in chronically injured patients with new risk factors for thromboembolism increased from 16% to 31% to 34% during T1, T2, and T3 (P = 0.001 and 0.87, respectively).

CONCLUSIONS

The CPG publication had only a modest effect on practice. Use of structured implementation further increased the adherence to some CPG recommendations for thromboembolism prophylaxis. Similar implementation strategies should be considered for CPG recommendations with low adherence and high potential for morbidity and mortality.

Provider adherence to implementation of clinical practice guidelines for neurogenic bowel in adults with spinal cord injury

BACKGROUND/OBJECTIVES

Clinical Practice Guidelines (CPGs) have been published on a number of topics in spinal cord injury (SCI) medicine. Research in the general medical literature shows that the distribution of CPGs has a minimal effect on physician practice without targeted implementation strategies. The purpose of this study was to determine (a) whether dissemination of an SCI CPG improved the likelihood that patients would receive CPG recommended care and (b) whether adherence to CPG recommendations could be improved through a targeted implementation strategy. Specifically, this study addressed the "Neurogenic Bowel Management in Adults with Spinal Cord Injury" Clinical Practice Guideline published in March 1998 by the Consortium for Spinal Cord Medicine

METHODS

CPG adherence was determined from medical record review at 6 Veterans Affairs SCI centers for 3 time periods: before guideline publication (T1), after guideline publication but before CPG implementation (T2), and after targeted CPG implementation (T3). Specific implementation strategies to enhance guideline adherence were chosen to address the barriers identified by SCI providers in focus groups before the intervention.

RESULTS

Overall adherence to recommendations related to neurogenic bowel did not change between T1 and T2 (P = not significant) but increased significantly between T2 and T3 (P < 0.001) for 3 of 6 guideline recommendations. For the other 3 guideline recommendations, adherence rates were noted to be high at T1.

CONCLUSIONS

While publication of the CPG alone did not alter rates of provider adherence, the use of a targeted implementation plan resulted in increases in adherence rates with some (3 of 6) CPG recommendations for neurogenic bowel management.

Long-term patency of saphenous vein and left internal mammary artery grafts after coronary artery bypass surgery: results from a Department of Veterans Affairs Cooperative Study

OBJECTIVES

This study defined long-term patency of saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts.

BACKGROUND

This VA Cooperative Studies Trial defined 10-year SVG patency in 1,074 patients and left IMA patency in 457 patients undergoing coronary artery bypass grafting (CABG).

METHODS

Patients underwent cardiac catheterizations at 1 week and 1, 3, 6, and 10 years after CABG.

RESULTS

Patency at 10 years was 61% for SVGs compared with 85% for IMA grafts (p < 0.001). If a SVG or IMA graft was patent at 1 week, that graft had a 68% and 88% chance, respectively, of being patent at 10 years. The SVG patency to the left anterior descending artery (LAD) (69%) was better (p < 0.001) than to the right coronary artery (56%), or circumflex (58%). Recipient vessel size was a significant predictor of graft patency, in vessels >2.0 mm in diameter SVG patency was 88% versus 55% in vessels </=2.0 mm (p < 0.001). Other positive significant predictors of graft patency were use of aspirin after bypass, older age, lower serum cholesterol, and lowest Canadian Functional Class (p < 0.001 to 0.058).

CONCLUSIONS

The 10-year patency of IMA grafts is better than SVGs. The 10-year patency for SVGs is better and the 10-year patency for IMA grafts is worse than expected. The 10-year patency of SVGs to the LAD is better than that to the right or circumflex. The best long-term predictors of SVG graft patency are grafting into the LAD and grafting into a vessel that is >2.0 mm in diameter.

Transthoracic versus transhiatal esophagectomy: a prospective study of 945 patients

OBJECTIVE

Debate continues as to whether transhiatal esophagectomy results in lower morbidity and mortality than transthoracic esophagectomy. Most data addressing this issue are derived from single-institution studies. To investigate this question from a nationwide multicenter perspective, we used the Veterans Administration National Surgical Quality Improvement Program to prospectively analyze risk factors for morbidity and mortality in patients undergoing transthoracic esophagectomy or transhiatal esophagectomy from 1991 to 2000.

METHODS

Univariate and multivariate analyses were performed on 945 patients (mean age, 63 +/- 10 years). There were 562 transthoracic esophagectomies and 383 transhiatal esophagectomies in 105 hospitals, with complete 30-day outcomes recorded.

RESULTS

There were no differences in recorded preoperative variables between the groups that might bias any comparisons. Overall mortality was 10.0% (56/562) for transthoracic esophagectomy and 9.9% (38/383) for transhiatal esophagectomy (P =.983). Morbidity occurred in 47% (266/562) of patients after transthoracic esophagectomy and in 49% (188/383) of patients after transhiatal esophagectomy (P =.596). Risk factors for mortality common to both groups included a serum albumin value of less than 3.5 g/dL, age greater than 65 years, and blood transfusion of greater than 4 units (P <.05). When comparing transthoracic esophagectomy with transhiatal esophagectomy, there was no difference in the incidence of respiratory failure, renal failure, bleeding, infection, sepsis, anastomotic complications, or mediastinitis. Wound dehiscence occurred in 5% (18/383) of patients undergoing transhiatal esophagectomy and only 2% (12/562) of patients undergoing transthoracic esophagectomy (P =.036).

CONCLUSIONS

These data demonstrate no significant differences in preoperative variables and postoperative mortality or morbidity between transthoracic esophagectomy and transhiatal esophagectomy on the basis of a 10-year, prospective, multi-institutional, nationwide study.

Outcomes after esophagectomy: a ten-year prospective cohort

BACKGROUND

The Department of Veterans Affairs National Surgical Quality Improvement Program is a unique resource to prospectively analyze surgical outcomes from a cross-section of surgical services nationally. We used this database to assess risk factors for morbidity and mortality after esophagectomy in Veterans Affairs Medical Centers from 1991 to 2001.

METHODS

A total of 1,777 patients underwent an esophagectomy at 109 Veterans Affairs hospitals with complete in-hospital and 30-day outcomes recorded. Bivariate and multivariable analyses were completed.

RESULTS

Thirty-day mortality was 9.8% (174/1,777) and the incidence of one or more of 20 predefined complications was 49.5% (880/1,777). The most frequent postoperative complications were pneumonia in 21% (380/1,777), respiratory failure in 16% (288/1,777), and ventilator support more than 48 hours in 22% (387/1,777). Preoperative predictors of mortality based on multivariable analysis included neoadjuvant therapy, blood urea nitrogen level of more than 40 mg/dL, alkaline phosphatase level of more than 125 U/L, diabetes mellitus, alcohol abuse, decreased functional status, ascites, and increasing age. Preoperative factors impacting morbidity were increasing age, dyspnea, diabetes mellitus, chronic obstructive pulmonary disease, alkaline phosphatase level of more than 125 U/L, lower serum albumin concentration, increased complexity score, and decreased functional status. Intraoperative risk factors for mortality included the need for transfusion; intraoperative risk factors for morbidity included the need for transfusion and longer operative time.

CONCLUSIONS

These data constitute the largest prospective outcomes cohort in the literature and document a near 50% morbidity rate and 10% mortality rate after esophagectomy. Data from this study can be used to better stratify patients before esophagectomy.

Association between initial empirical therapy and decreased length of stay among veteran patients hospitalized with community acquired pneumonia

This investigation assessed the impact of initial empirical antimicrobial therapy on the outcome of therapy for community acquired pneumonia (CAP) patients and on patients' length of stay (LOS) in the hospital. Hospital records for 165 patients with pneumonia admitted to the Edward Hines, Jr. VA Hospital between 1 October 1997, and 31 March 2000, were reviewed. Criteria for CAP were met for 92 of 165 patients. Comparisons were made between patients treated with azithromycin and with other parenteral antibiotics (the reference group). No statistical differences were observed between the treatment groups for the risk factors. The azithromycin group patients were slightly older with a mean age of 69 years versus 66 years (P=0.23). Patients treated with parenteral azithromycin had on average, a shorter length of hospitalization namely 4.6 days compared with 9.7 days for patients treated with the other antibiotics (log-rank test, P=0.0001). In order to make the two groups of patients more alike we considered patients' data set without intensive care unit (ICU) admissions. The conclusion was the same namely azithromycin monotherapy was associated with a decreased duration of hospital stay.

Comparison of surgical outcomes between teaching and nonteaching hospitals in the Department of Veterans Affairs

OBJECTIVE

To determine whether the investment in postgraduate education and training places patients at risk for worse outcomes and higher costs than if medical and surgical care was delivered in nonteaching settings.

SUMMARY BACKGROUND DATA

The Veterans Health Administration (VA) plays a major role in the training of medical students, residents, and fellows.

METHODS

The database of the VA National Surgical Quality Improvement Program was analyzed for all major noncardiac operations performed during fiscal years 1997, 1998, and 1999. Teaching status of a hospital was determined on the basis of a background and structure questionnaire that was independently verified by a research fellow. Stepwise logistic regression was used to construct separate models predictive of 30-day mortality and morbidity for each of seven surgical specialties and eight operations. Based on these models, a severity index for each patient was calculated. Hierarchical logistic regression models were then created to examine the relationship between teaching versus nonteaching hospitals and 30-day postoperative mortality and morbidity, after adjusting for patient severity.

RESULTS

Teaching hospitals performed 81% of the total surgical workload and 90% of the major surgery workload. In most specialties in teaching hospitals, the residents were the primary surgeons in more than 90% of the operations. Compared with nonteaching hospitals, the patient populations in teaching hospitals had a higher prevalence of risk factors, underwent more complex operations, and had longer operation times. Risk-adjusted mortality rates were not different between the teaching and nonteaching hospitals in the specialties and operations studied. The unadjusted complication rate was higher in teaching hospitals in six of seven specialties and four of eight operations. Risk adjustment did not eliminate completely these differences, probably reflecting the relatively poor predictive validity of some of the risk adjustment models for morbidity. Length of stay after major operations was not consistently different between teaching and nonteaching hospitals.

CONCLUSION

Compared with nonteaching hospitals, teaching hospitals in the VA perform the majority of complex and high-risk major procedures, with comparable risk-adjusted 30-day mortality rates. Risk-adjusted 30-day morbidity rates in teaching hospitals are higher in some specialties and operations than in nonteaching hospitals. Although this may reflect the weak predictive validity of some of the risk adjustment models for morbidity, it may also represent suboptimal processes and structures of care that are unique to teaching hospitals. Despite good quality of care in teaching hospitals, as evidenced by the 30-day mortality data, efforts should be made to examine further the structures and processes of surgical care prevailing in these hospitals.

Predictors of graft patency 3 years after coronary artery bypass graft surgery. Department of Veterans Affairs Cooperative Study Group No. 297

OBJECTIVES

The purpose of this analysis was to define the factors that predict 3-year graft patency.

BACKGROUND

The success of coronary artery bypass graft surgery (CABG) is dependent on vein graft patency after the operation. It has been well established by a series of Department of Veterans Affairs Cooperative Trials that aspirin (325 mg daily) improves saphenous vein graft patency early (7 to 10 days) and at 1 year, but not at 3 years after CABG. This analysis, based on one of these trials, defined factors that predict 3-year graft patency.

METHODS

This analysis consisted of 266 patients, with 656 grafts that were patent 7 to 10 days after the operation, who underwent 3-year catheterization. To determine which patient-specific and/or graft-specific factors, or both, predict graft occlusion, a multivariate logistic regression analysis in terms of latent variables was used. It yielded a model that also took into account possible intraclass correlations.

RESULTS

For a vein graft that was patent at 7 to 10 days after the operation, the positive predictors, according to univariate analysis, for that graft being patent at 3 years were cross-clamp time < or = 80 min (p < 0.001), vein preservation solution temperature < or = 5 degrees C (p = 0.009), bypass time < or = 2 h (p = 0.042), number of proximal anastomoses < or = 2 (p = 0.018), operation time < or = 5 h (p = 0.044) and continuous versus intermittent cross-clamp technique (p = 0.024). There was also a trend with regard to recipient artery diameter > 1.5 mm (p = 0.063), serum cholesterol < or = 225 mg/dl (p = 0.084) and single versus sequential or Y vein graft (p = 0.060). Factors not predictive of 3-year patency were age, race, smoking history, high density lipoprotein cholesterol, vein source (thigh vs. calf), coronary artery grafted and aspirin treatment. Of all the predictors obtained in the univariate analysis, the only variables that were sufficient to yield a good model within the multivariate analysis were solution temperature (p = 0.004), serum cholesterol (p = 0.024), number of proximal anastomoses (p = 0.032) and recipient artery diameter (p = 0.034).

CONCLUSIONS

For a patient with patent vein grafts 7 to 10 days after the operation, predictors of 3-year graft patency are more closely related to operative techniques and underlying disease and not to aspirin treatment.