Successful linking of the Society of Thoracic Surgeons Database to Social Security data to examine the accuracy of Society of Thoracic Surgeons mortality data

Genome Sequencing is Critical for Forecasting Outcomes Following Congenital Cardiac Surgery

While exome and whole genome sequencing have transformed medicine by elucidating the genetic underpinnings of both rare and common complex disorders, its utility to predict clinical outcomes remains understudied. Here, we used artificial intelligence (AI) technologies to explore the predictive value of genome sequencing in forecasting clinical outcomes following surgery for congenital heart defects (CHD). We report results for a cohort of 2,253 CHD patients from the Pediatric Cardiac Genomics Consortium with a broad range of complex heart defects, pre- and post-operative clinical variables and exome sequencing. Damaging genotypes in chromatin-modifying and cilia-related genes were associated with an elevated risk of adverse post-operative outcomes, including mortality, cardiac arrest and prolonged mechanical ventilation. The impact of damaging genotypes was further amplified in the context of specific CHD phenotypes, surgical complexity and extra-cardiac anomalies. The absence of a damaging genotype in chromatin-modifying and cilia-related genes was also informative, reducing the risk for adverse postoperative outcomes. Thus, genome sequencing enriches the ability to forecast outcomes following congenital cardiac surgery.

Multiarterial vs Single-Arterial Coronary Surgery: 10-Year Follow-up of 1 Million Patients

BACKGROUND

Although many options exist for multivessel coronary revascularization, controversy persists over whether multiarterial grafting (MAG) confers a survival advantage over single-arterial grafting (SAG) with saphenous vein in coronary artery bypass grafting (CABG). This study sought to compare longitudinal survival between patients undergoing MAG and those undergoing SAG.

METHODS

All patients undergoing isolated CABG with ≥2 bypass grafts in The Society of Thoracic Surgeons Adult Cardiac Surgery Database (2008-2019) were linked to the National Death Index. Risk adjustment was performed using inverse probability weighting and multivariable modeling. The primary end point was longitudinal survival. Subpopulation analyses were performed and volume thresholds were analyzed to determine optimal benefit.

RESULTS

A total of 1,021,632 patients underwent isolated CABG at 1108 programs (100,419 MAG [9.83%]; 920,943 SAG [90.17%]). Median follow-up was 5.30 years (range, 0-12 years). After risk adjustment, all characteristics were well balanced. At 10 years, MAG was associated with improved unadjusted (hazard ratio, 0.59; 95% CI 0.58-0.61) and adjusted (hazard ratio, 0.86; 95% CI, 0.85-0.88) 10-year survival. Center volume of ≥10 MAG cases/year was associated with benefit. MAG was associated with an overall survival advantage over SAG in all subgroups, including stable coronary disease, acute coronary syndrome, and acute infarction. Survival was equivalent to that with SAG for patients age ≥80 years and those with severe heart failure, renal failure, peripheral vascular disease, or obesity. Only patients with a body mass index ≥40 kg/m2 had superior survival with SAG.

CONCLUSIONS

Multiarterial CABG is associated with superior long-term survival and should be the surgical multivessel revascularization strategy of choice for patients with a body mass index of less than 40 kg/m2.

The Society of Thoracic Surgeons 2021 Adult Cardiac Surgery Risk Models for Multiple Valve Operations

BACKGROUND

The Society of Thoracic Surgeons (STS) Quality Measurement Task Force has developed risk models and composite performance measures for isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR), isolated mitral valve replacement or repair (MVRR), AVR+CABG, and MVRR+CABG. To further enhance its portfolio of risk-adjusted performance metrics, STS has developed new risk models for multiple valve operations ± CABG procedures.

METHODS

Using July 2011 to June 2019 STS Adult Cardiac Surgery Database data, risk models for AVR+MVRR (n = 31,968) and AVR+MVRR+CABG (n = 12,650) were developed with the following endpoints: Operative Mortality, major morbidity (any 1 or more of the following: cardiac reoperation, deep sternal wound infection/mediastinitis, stroke, prolonged ventilation, and renal failure), and combined mortality and/or major morbidity. Data were divided into development (July 2011 to June 2017; n = 35,109) and validation (July 2017 to June 2019; n = 9509) samples. Predictors were selected by assessing model performance and clinical face validity of full and progressively more parsimonious models. Performance of the resulting models was evaluated by assessing discrimination and calibration.

RESULTS

C-statistics for the overall population of multiple valve ± CABG procedures were 0.7086, 0.6734, and 0.6840 for mortality, morbidity, and combined mortality and/or morbidity in the development sample, and 0.6953, 0.6561, and 0.6634 for the same outcomes, respectively, in the validation sample.

CONCLUSIONS

New STS Adult Cardiac Surgery Database risk models have been developed for multiple valve ± CABG operations, and these models will be used in subsequent STS performance metrics.

Loss of Pulmonary Vascular Volume as a Predictor of Right Ventricular Dysfunction and Mortality in Acute Pulmonary Embolism

BACKGROUND

In acute pulmonary embolism, chest computed tomography angiography derived metrics, such as the right ventricle (RV): left ventricle ratio are routinely used for risk stratification. Paucity of intraparenchymal blood vessels has previously been described, but their association with clinical biomarkers and outcomes has not been studied. We sought to determine if small vascular volumes measured on computed tomography scans were associated with an abnormal RV on echocardiography and mortality. We hypothesized that decreased small venous volume would be associated with greater RV dysfunction and increased mortality.

METHODS

A retrospective cohort of patients with intermediate risk pulmonary embolism admitted to Brigham and Women's Hospital between 2009 and 2017 was assembled, and clinical and radiographic data were obtained. We performed 3-dimensional reconstructions of vasculature to assess intraparenchymal vascular volumes. Statistical analyses were performed using multivariable regression and cox proportional hazards models, adjusting for age, sex, lung volume, and small arterial volume.

RESULTS

Seven hundred twenty-two subjects were identified of whom 573 had documented echocardiography. A 50% reduction in small venous volume was associated with an increased risk of RV dilation (relative risk: 1.38 [95% CI, 1.18-1.63], P<0.001), RV dysfunction (relative risk: 1.62 [95% CI, 1.36-1.95], P<0.001), and RV strain (relative risk: 1.67 [95% CI, 1.37-2.04], P<0.001); increased cardiac biomarkers, and higher 30-day and 90-day mortality (hazard ratio: 2.50 [95% CI, 1.33-4.67], P=0.004 and hazard ratio: 1.84 [95% CI, 1.11-3.04], P=0.019, respectively).

CONCLUSIONS

Loss of small venous volume quantified from computed tomography angiography is associated with increased risk of abnormal RV on echocardiography, abnormal cardiac biomarkers, and higher risk of 30- and 90-day mortality. Small venous volume may be a useful marker for assessing disease severity in acute pulmonary embolism.

Current Penetration, Completeness, and Representativeness of The Society of Thoracic Surgeons Adult Cardiac Surgery Database

BACKGROUND

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) is the largest cardiac surgical database in the world. Linked data from STS ACSD and the CMS Medicare database were used to determine contemporary completeness, penetration, and representativeness of STS ACSD.

METHODS

Using variables common to both STS and CMS databases, STS procedures were linked to CMS data for all CMS CABG discharges between 2000 and 2018, inclusive. For each CMS CABG hospitalization, it was determined whether a matching STS record existed.

RESULTS

Center-level penetration (number of CMS sites with at least one matched STS participant divided by total number of CMS CABG sites) increased from 45% in 2000 to 95% in 2018. In 2018, 949 of 1,004 CMS CABG sites (95%) were linked to an STS site. Patient-level penetration (number of CMS CABG hospitalizations at STS sites divided by total number of CMS CABG hospitalizations) increased from 51% in 2000 to 97% in 2018. In 2018, 68,584 of 70,818 CMS CABG hospitalizations (97%) occurred at an STS site. Completeness of case inclusion at STS sites (number of CMS CABG cases at STS sites linked to STS records divided by total number of CMS CABG cases at STS sites) increased from 88% in 2000 to 98% in 2018. In 2018, 66,673 of 68,108 CMS CABG hospitalizations at STS sites (98%) were linked to an STS record.

CONCLUSIONS

Linkage of STS and CMS databases demonstrates high and increasing penetration and completeness of STS ACSD. STS ACSD now includes 97% of CABG in USA.

Transesophageal Echocardiography in Patients Undergoing Coronary Artery Bypass Graft Surgery

BACKGROUND

The impact of utilization of intraoperative transesophageal echocardiography (TEE) at the time of isolated coronary artery bypass grafting (CABG) on clinical decision making and associated outcomes is not well understood.

OBJECTIVES

The purpose of this study was to determine the association of TEE with post-CABG mortality and changes to the operative plan.

METHODS

A retrospective cohort study of planned isolated CABG patients from the Society of Thoracic Surgeons Adult Cardiac Surgery Database between January 1, 2011, and June 30, 2019, was performed. The exposure variable of interest was use of intraoperative TEE during CABG compared with no TEE. The primary outcome was operative mortality. The association of TEE with unplanned valve surgery was also assessed.

RESULTS

Of 1,255,860 planned isolated CABG procedures across 1218 centers, 676,803 (53.9%) had intraoperative TEE. The percentage of patients receiving intraoperative TEE increased over time from 39.9% in 2011 to 62.1% in 2019 (p trend <0.0001). CABG patients undergoing intraoperative TEE had lower odds of mortality (adjusted odds ratio: 0.95; 95% confidence interval: 0.91 to 0.99; p = 0.025), with heterogeneity across STS risk groups (p interaction = 0.015). TEE was associated with increased odds of unplanned valve procedure in lieu of planned isolated CABG (adjusted odds ratio: 4.98; 95% confidence interval: 3.98 to 6.22; p < 0.0001).

CONCLUSIONS

Intraoperative TEE usage during planned isolated CABG is associated with lower operative mortality, particularly in higher-risk patients, as well as greater odds of unplanned valve procedure. These findings support usage of TEE to improve outcomes for isolated CABG for high-risk patients.

Impact of Transcatheter Aortic Valve Replacement on Risk Profiles of Surgical Aortic Valve Replacement Patients

BACKGROUND

The advent of transcatheter aortic valve replacement (TAVR) has changed which patients undergo surgical aortic valve replacement (SAVR). We sought to understand the impact of TAVR on the characteristics of SAVR patients in the United States.

METHODS

A cohort of 2959 patients who underwent isolated SAVR at 11 US hospitals that perform both TAVR and SAVR from 2013 through 2017 were grouped by the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database version (v)2.73 (2011-2014), v2.81 (2014-2017), and v2.9 (2017) to assess temporal trends in patient characteristics.

RESULTS

Over time, SAVR patients were younger with fewer preoperative comorbidities. There was a significant decrease in median STS predicted risk of mortality (PROM) score (2.0 vs. 1.8 vs. 1.3, p < 0.001, in v2.73 vs. v2.81 vs. v2.9). Specifically, there were fewer high-risk (STS PROM > 8%: 4.3% vs. 4.7% vs. 1.2%, p = 0.03) and intermediate-risk (STS PROM 4% to 8%: 16.3% vs. 11.7% vs. 4.3%, p < 0.001) patients. The proportion of patients with bicuspid aortic valve disease increased significantly (11.2% vs. 26.9% vs. 36.6%, p < 0.001). There were no differences in operative mortality (1.9% vs. 2.1% vs. 1.4%, p = 0.75).

CONCLUSIONS

The introduction of TAVR has already impacted the demographics, clinical characteristics and risk profiles of patients undergoing SAVR in the US. Now that TAVR is approved for low-risk patients, SAVR is likely to be reserved for younger patients who are willing to receive a mechanical valve and for patients with aortopathy, coronary artery disease, or concomitant mitral or tricuspid pathology.

Out-of-Hospital 30-day Deaths After Cardiac Surgery Are Often Underreported

BACKGROUND

Operative mortality (in-hospital during the index admission or within 30 days of the procedure after discharge) is commonly used as a quality of care measure for public reporting of cardiac surgery outcomes, but the ability to capture out-of-hospital deaths accurately remains undetermined. The objective of the study was to estimate the impact of incomplete reporting of out-of-hospital deaths on hospital risk-adjusted mortality and outlier status.

METHODS

New York State's 2014 to 2016 cardiac registry data were used to compare the capture of 30-day postprocedure deaths after discharge with and without the use of national and state-level vital statistics data for all 54,442 patients undergoing isolated coronary artery bypass graft, cardiac valve surgery, or both. Hospital risk-adjusted operative mortality rates and mortality outliers were compared based on statistical models that were developed with and without the use of vital statistics data.

RESULTS

Thirty-day deaths postprocedure after discharge ranged from 10% to 39% of all operative deaths among cardiac surgical procedures. More than 30% of these deaths were missing without vital statistics confirmation for 7 of the 10 cardiac procedures examined, and more than 40% were missing for 5 of the procedures examined. When vital statistics data were used to confirm 30-day postprocedure deaths after discharge, an additional high outlier for valve surgery was identified.

CONCLUSIONS

Operative mortality after cardiac surgery is often underreported owing to a considerable percentage of out-of-hospital cardiac surgery deaths that are missed by reporting centers. This can adversely affect the assessment of hospital risk-adjusted mortality in public reports.

Vibration transmittance measures sternotomy stability - a preliminary study in human cadavers

BACKGROUND

Stability is essential for the normal healing of a sternotomy. Mechanical vibration transmittance may provide a new means of early detection of diastasis in the sternotomy and thus enable the prevention of further complications. We sought to confirm that vibration transmittance detects sternal diastasis in human tissue.

METHODS

Ten adult human cadavers (8 males and 2 females) were used for sternal assessments with a device constructed in-house to measure the transmittance of a vibration stimulus across the median sternotomy at the second, third, and fourth costal cartilage. Intact bone was compared to two fixed bone junctions, namely a stable wire fixation and an unstable wire fixation with a 10 mm wide diastasis mimicking a widely rupturing sternotomy. A generalized Linear Mixed Model with the lme function was used to determine the ability of the vibration transmittance device to differentiate mechanical settings in the sternotomy.

RESULTS

The transmitted vibration power was statistically significantly different between the intact chest and stable sternotomy closure, stable and unstable closure, as well as intact and unstable closure (t-values and p-values respectively: t = 6.87, p < 0.001; t = 7.41, p < 0.001; t = 14.3, p < 0.001). The decrease of vibration transmittance from intact to stable at all tested costal levels was 78%, from stable to unstable 58%, and from intact to unstable 91%. The vibration transmittance power was not statistically significantly different between the three tested costal levels (level 3 vs. level 2; level 4 vs. level 2; level 4 vs. level 3; t-values and p-values respectively t = - 0.36, p = 0.723; t = 0.35, p = 0.728; t = 0.71, p = 0.484).

CONCLUSIONS

Vibration transmittance analysis differentiates the intact sternum, wire fixation with exact apposition, and wire fixation with a gap. The gap detection capability is not dependent on the tested costal level. The method may prove useful in the early detection of sternal instability and warrants further exploration.

The Society of Thoracic Surgeons 2018 Adult Cardiac Surgery Risk Models: Part 2-Statistical Methods and Results

BACKGROUND

The Society of Thoracic Surgeons (STS) uses statistical models to create risk-adjusted performance metrics for Adult Cardiac Surgery Database (ACSD) participants. Because of temporal changes in patient characteristics and outcomes, evolution of surgical practice, and additional risk factors available in recent ACSD versions, completely new risk models have been developed.

METHODS

Using July 2011 to June 2014 ACSD data, risk models were developed for operative mortality, stroke, renal failure, prolonged ventilation, mediastinitis/deep sternal wound infection, reoperation, major morbidity or mortality composite, prolonged postoperative length of stay, and short postoperative length of stay among patients who underwent isolated coronary artery bypass grafting surgery (n = 439,092), aortic or mitral valve surgery (n = 150,150), or combined valve plus coronary artery bypass grafting surgery (n = 81,588). Separate models were developed for each procedure and endpoint except mediastinitis/deep sternal wound infection, which was analyzed in a combined model because of its infrequency. A surgeon panel selected predictors by assessing model performance and clinical face validity of full and progressively more parsimonious models. The ACSD data (July 2014 to December 2016) were used to assess model calibration and to compare discrimination with previous STS risk models.

RESULTS

Calibration in the validation sample was excellent for all models except mediastinitis/deep sternal wound infection, which slightly underestimated risk and will be recalibrated in feedback reports. The c-indices of new models exceeded those of the last published STS models for all populations and endpoints except stroke in valve patients.

CONCLUSIONS

New STS ACSD risk models have generally excellent calibration and discrimination and are well suited for risk adjustment of STS performance metrics.

Impact of Accurate 30-Day Status on Operative Mortality: Wanted Dead or Alive, Not Unknown

BACKGROUND

Risk-adjusted operative mortality is the most important quality metric in cardiac surgery for determining The Society of Thoracic Surgeons (STS) Composite Score for star ratings. Accurate 30-day status is required to determine STS operative mortality. The goal of this study was to determine the effect of unknown or missing 30-day status on risk-adjusted operative mortality in a regional STS Adult Cardiac Surgery Database cooperative and demonstrate the ability to correct these deficiencies by matching with an administrative database.

METHODS

STS Adult Cardiac Surgery Database data were submitted by 27 hospitals from five hospital systems to the Texas Quality Initiative (TQI), a regional quality collaborative. TQI data were matched with a regional hospital claims database to resolve unknown 30-day status. The risk-adjusted operative mortality observed-to-expected (O/E) ratio was determined before and after matching to determine the effect of unknown status on the operative mortality O/E.

RESULTS

TQI found an excessive (22%) unknown 30-day status for STS isolated coronary artery bypass grafting cases. Matching the TQI data to the administrative claims database reduced the unknowns to 7%. The STS process of imputing unknown 30-day status as alive underestimates the true operative mortality O/E (1.27 before vs 1.30 after match), while excluding unknowns overestimates the operative mortality O/E (1.57 before vs 1.37 after match) for isolated coronary artery bypass grafting.

CONCLUSIONS

The current STS algorithm of imputing unknown 30-day status as alive and a strategy of excluding cases with unknown 30-day status both result in erroneous calculation of operative mortality and operative mortality O/E. However, external validation by matching with an administrative database can improve the accuracy of clinical databases such as the STS Adult Cardiac Surgery Database.

The Global Tracheostomy Collaborative: one institution's experience with a new quality improvement initiative

OBJECTIVE

Given the low frequency of adverse events after tracheostomy, individual institutions struggle to collect outcome data to generate effective quality improvement protocols. The Global Tracheostomy Collaborative (GTC) is a multi-institutional, multi-disciplinary organization that utilizes a prospective database to collect data on patients undergoing tracheostomy. We describe our institution's preliminary experience with this collaborative. It was hypothesized that entry into the database would be non-burdensome and could be easily and accurately initiated by skilled specialists at the time of tracheostomy placement and completed at time of patient discharge.

METHODS

Demographic, diagnostic, and outcome data on children undergoing tracheostomy at our institution from January 2013 to June 2015 were entered into the GTC database, a database collected and managed by REDCap (Research Electronic Data Capture). All data entry was performed by pediatric otolaryngology fellows and all post-operative updates were completed by a skilled tracheostomy nurse. Tracked outcomes included accidental decannulation, failed decannulation, tracheostomy tube obstruction, bleeding/tracheoinnominate fistula, and tracheocutaneous fistula.

RESULTS

Data from 79 patients undergoing tracheostomy at our institution were recorded. Database entry was straightforward and entry of patient demographic information, medical comorbidities, surgical indications, and date of tracheostomy placement was completed in less than 5min per patient. The most common indication for surgery was facilitation of ventilation in 65 patients (82.3%). Average time from admission to tracheostomy was 62.6 days (range 0-246). Stomal breakdown was seen in 1 patient. A total of 72 patients were tracked to hospital discharge with 53 patients surviving (88.3%). No mortalities were tracheostomy-related.

CONCLUSION

The Global Tracheostomy Collaborative is a multi-institutional, multi-disciplinary collaborative that collects data on patients undergoing tracheostomy. Our experience proves proof of concept of entering demographics and outcome data into the GTC database in a manner that was both accurate and not burdensome to those participating in data entry. In our tertiary care, pediatric academic medical center, tracheostomy continues to be a safe procedure with no major tracheostomy-related morbidities occurring in this patient population involvement with the GTC has shown opportunities for improvement in communication and coordination with other tracheostomy-related disciplines.

Penetration, Completeness, and Representativeness of The Society of Thoracic Surgeons Adult Cardiac Surgery Database

BACKGROUND

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) has been successfully linked to the Centers for Medicare and Medicaid (CMS) Medicare database, thereby facilitating comparative effectiveness research and providing information about long-term follow-up and cost. The present study uses this link to determine contemporary completeness, penetration, and representativeness of the STS ACSD.

METHODS

Using variables common to both STS and CMS databases, STS operations were linked to CMS data for all CMS coronary artery bypass graft (CABG) surgery hospitalizations discharged between 2000 and 2012, inclusive. For each CMS CABG hospitalization, it was determined whether a matching STS record existed.

RESULTS

Center-level penetration (number of CMS sites with at least one matched STS participant divided by the total number of CMS CABG sites) increased from 45% in 2000 to 90% in 2012. In 2012, 973 of 1,081 CMS CABG sites (90%) were linked to an STS site. Patient-level penetration (number of CMS CABG hospitalizations done at STS sites divided by the total number of CMS CABG hospitalizations) increased from 51% in 2000 to 94% in 2012. In 2012, 71,634 of 76,072 CMS CABG hospitalizations (94%) occurred at an STS site. Completeness of case inclusion at STS sites (number of CMS CABG cases at STS sites linked to STS records divided by the total number of CMS CABG cases at STS sites) increased from 88% in 2000 to 98% in 2012. In 2012, 69,213 of 70,932 CMS CABG hospitalizations at STS sites (98%) were linked to an STS record.

CONCLUSIONS

Linkage of STS and CMS databases demonstrates high and increasing penetration and completeness of the STS database. Linking STS and CMS data facilitates studying long-term outcomes and costs of cardiothoracic surgery.

The science of assessing the outcomes and improving the quality of the congenital and paediatric cardiac care

PURPOSE OF REVIEW

Although significant progress has been made in the care of patients with paediatric and congenital cardiac disease, optimization of outcomes remains a constant goal. This review article will discuss the latest advances in the science of assessing the outcomes and improving the quality of the congenital and paediatric cardiac care, and will also review some of the latest associated research.

RECENT FINDINGS

Important advances continue to be made in each of the following domains: standardized nomenclature; established uniform core dataset; evaluation of case complexity; verification of the completeness and accuracy of the data; collaboration between subspecialties; strategies for longitudinal follow-up; and incorporating quality improvement. In January 2015, the Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) will begin voluntary public reporting of programmatic congenital cardiac surgical outcomes using a new risk model that includes both procedural risk (as defined by the procedure itself and STAT Categories) and a number of patient-specific characteristics including age, weight, prior cardiothoracic operation, prematurity, chromosomal abnormalities, syndromes, noncardiac congenital anatomic abnormalities and preoperative factors. Clinical databases have been linked with administrative database to answer questions neither dataset can answer independently, providing new information about long-term mortality, rates of rehospitalization, long-term morbidity, comparative effectiveness of various treatments, and the cost of healthcare. Multiple research initiatives have recently been published using STS-CHSD.

SUMMARY

The science of assessing the outcomes and improving the quality of congenital and paediatric cardiac care continues to evolve. Recent advances will facilitate the continued evolution of a meaningful method of multiinstitutional outcomes analysis for congenital and paediatric cardiac surgery.

[Completeness assessment of the Breton registry of congenital abnormalities: A checking tool based on hospital discharge data]

BACKGROUND

Exhaustiveness is required for registries. In the Breton registry of congenital abnormalities, cases are recorded at the source. We use hospital discharge data in order to verify the completeness of the registry. In this paper, we present a computerized tool for completeness assessment applied to the Breton registry.

METHODS

All the medical information departments were solicited once a year, asking for infant medical stays for newborns alive at one year old and for mother's stays if not. Files were transmitted by secure messaging and data were processed on a secure server. An identity-matching algorithm was applied and a similarity score calculated. When the record was not linked automatically or manually, the medical record had to be consulted. The exhaustiveness rate was assessed using the capture recapture method and the proportion of cases matched manually was used to assess the identity matching algorithm.

RESULTS

The computerized tool bas been used in common practice since June 2012 by the registry investigators. The results presented concerned the years 2011 and 2012. There were 470 potential cases identified from the hospital discharge data in 2011 and 538 in 2012, 35 new cases were detected in 2011 (32 children born alive and 3 stillborn), and 33 in 2012 (children born alive). There were respectively 85 and 137 false-positive cases. The theorical exhaustiveness rate reached 91% for both years. The rate of exact matching amounted to 68%; 6% of the potential cases were linked manually.

CONCLUSION

Hospital discharge databases contribute to the quality of the registry even though reports are made at the source. The implemented tool facilitates the investigator's work. In the future, use of the national identifying number, when allowed, should facilitate linkage between registry data and hospital discharge data.