Does clinical evidence support ICD-9-CM diagnosis coding of complications?

Validity of myocardial infarction diagnoses in administrative databases: a systematic review

BACKGROUND

Though administrative databases are increasingly being used for research related to myocardial infarction (MI), the validity of MI diagnoses in these databases has never been synthesized on a large scale.

OBJECTIVE

To conduct the first systematic review of studies reporting on the validity of diagnostic codes for identifying MI in administrative data.

METHODS

MEDLINE and EMBASE were searched (inception to November 2010) for studies: (a) Using administrative data to identify MI; or (b) Evaluating the validity of MI codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value (PPV), negative predictive value, or Kappa scores) for MI, or data sufficient for their calculation. Additonal articles were located by handsearch (up to February 2011) of original papers. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

Thirty studies published from 1984-2010 were included; most assessed codes from the International Classification of Diseases (ICD)-9th revision. Sensitivity and specificity of hospitalization data for identifying MI in most [≥50%] studies was ≥86%, and PPV in most studies was ≥93%. The PPV was higher in the more-recent studies, and lower when criteria that do not incorporate cardiac troponin levels (such as the MONICA) were employed as the gold standard. MI as a cause-of-death on death certificates also demonstrated lower accuracy, with maximum PPV of 60% (for definite MI).

CONCLUSIONS

Hospitalization data has higher validity and hence can be used to identify MI, but the accuracy of MI as a cause-of-death on death certificates is suboptimal, and more studies are needed on the validity of ICD-10 codes. When using administrative data for research purposes, authors should recognize these factors and avoid using vital statistics data if hospitalization data is not available to confirm deaths from MI.

Adherence to performance measures and outcomes among men treated for prostate cancer

PURPOSE

We assessed the relationship between health care system performance on nationally endorsed prostate cancer quality of care measures and prostate cancer treatment outcomes.

MATERIALS AND METHODS

This retrospective cohort study included 48,050 men from SEER-Medicare linked data diagnosed with localized prostate cancer between 2004 and 2009, and followed through 2010. Based on a composite quality measure we categorized the health care systems in which these men were treated into 1-star (bottom 20%), 2-star (middle 60%) and 3-star (top 20%) systems. We then examined the association of health care system level quality of care with outcomes using multivariable logistic and Cox regression.

RESULTS

Patients who underwent prostatectomy in 3-star vs 1-star health care systems were at lower risk for perioperative complications (OR 0.80, 95% CI 0.64-1.00). However, they were more likely to undergo a procedure addressing treatment related morbidity, eg for sexual morbidity (11.3% vs 7.8%, p = 0.043). In patients who received radiotherapy star ranking was not associated with treatment related morbidity. In all patients star ranking was not significantly associated with all-cause mortality (HR 0.99, 95% CI 0.84-1.15) or secondary cancer therapy (HR 1.04, 95% CI 0.91-1.20).

CONCLUSIONS

We found no consistent association between health care system quality and outcomes, which questions how meaningful these measures ultimately are for patients. Thus, future studies should focus on developing more discriminative quality measures.

A novel method for detecting inpatient pediatric asthma encounters using administrative data

Multiple methods for detecting asthma encounters are used today in public surveillance, quality reporting, and clinical research. Failure to detect asthma encounters can make it difficult to measure the scope and effectiveness of hospital or community-based interventions important in comparative effectiveness research and accountable care. Given the pairing of asthma with certain respiratory conditions, the objective of this study was to develop and test an asthma detection algorithm with specificity and sensitivity using 2 criteria: (1) principal discharge diagnosis and (2) asthma diagnosis code position. A medical record review was conducted (n=191) as the gold standard for identifying asthma encounters given objective criteria. The study team observed that for certain principal respiratory diagnoses (n=110), the observed odds ratio that encounters were for asthma when asthma was coded in the second or third code position was not significantly different than when asthma was coded as the principal diagnosis, 0.36 (P=0.42) and 0.18 (P=0.14), respectively. In contrast, the observed odds ratio was significantly different when asthma was coded in the fourth or fifth positions (P<.001). This difference remained after adjusting for covariates. Including encounters with asthma in 1 of the 3 first positions increased the detection sensitivity to 0.84 [95% confidence interval (CI): 0.76-0.92] while increasing the false positive rate to 0.19 [95% CI: 0.07-0.31]. Use of the proposed algorithm significantly improved the reporting accuracy [0.83 95%CI:0.76-0.90] over use of (1) the principal diagnosis alone [0.55 95% CI:0.46-0.64] or (2) all encounters with asthma 0.66 [95% CI:0.57-0.75]. Bed days resulting from asthma encounters increased 64% over use of the principal diagnosis alone. Given these findings, an algorithm using certain respiratory principal diagnoses and asthma diagnosis code position can reliably improve asthma encounter detection for population-based health impact measurement.

Use of International Classification of Diseases, Ninth Revision, Clinical Modification, codes to identify inpatient fall-related injuries

OBJECTIVES

To compare falls and fall-related injuries that a fall evaluator or hospital incident report identified with injuries identified according to discharge International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for the same set of inpatient episodes of care.

DESIGN

Prospective, descriptive study.

SETTING

Sixteen adult general medical and surgical units in a major urban teaching hospital.

PARTICIPANTS

All adults who sustained a fall with injury during a 5-year period (380 falls with injury).

MEASUREMENTS

Falls that a fall evaluator or hospital incident report identified were classified according to their injury severity. Discharge abstracts provided diagnosis codes (ICD-9-CM) for the discharge, including fall-related injury codes.

RESULTS

Three hundred forty-three inpatient falls with injury (90.2%) resulted in temporary harm to the individual; the remaining 37 falls (9.8%) resulted in more-serious harm. Sixteen of the 37 falls with injury extending hospitalization or resulting in death were identified using Centers for Medicare and Medicaid Services (CMS)-targeted injury code ranges combined with present-on-admission indicators. Of the 21 falls with injury that were not identified, nine (42.9%) lacked documentation of any injury, and seven (33.3%) identified other injuries outside the CMS-targeted injury code ranges.

CONCLUSION

The CMS-targeted ICD-9-CM codes used to identify fall-related injuries in claims data do not always detect the most-serious falls.

In-hospital death and hospital-acquired complications among patients undergoing partial cystectomy for bladder cancer in the United States

BACKGROUND

Partial cystectomy (PC) is a therapeutic option for select patients with bladder cancer, but its associated perioperative risks and costs are unknown. We estimated annual rates of PC in a nationally representative sample of hospitals, and analyzed whether hospital volume affects postoperative outcomes and costs in patients undergoing PC.

METHODS

From the Nationwide Inpatient Sample, we selected a weighted cohort of patients with bladder cancer who underwent PC between 2002 and 2008. Differences in length of stay, charges, and clinical outcomes were calculated based on operative volume, and univariate and multivariate regression models were fitted to predict in-hospital mortality (IHM) and hospital-acquired conditions.

RESULTS

A total of 10,780 patients with bladder cancer who underwent PC were identified with an annual rate between 1457 and 1628 cases. IHM rates were 1.8%, constituting 195 patients (between 9 and 46 annually). A total of 417 patients (3.9%) experienced a "never event" complication, which Medicare no longer reimburses. The mean annual hospital volume of patients who died was 1.7 cases/y compared with 2.4 cases/y among those without fatal complications. No cases of IHM were identified among hospitals performing at least 5 partial cystectomies/y. In a multivariate regression model increased hospital volume was independently associated with decreased mortality (odds ratio = 0.70, 95% confidence interval; 0.60-0.80).

CONCLUSIONS

Approximately 1 in 25 patients undergoing PC experience a hospital-acquired complication, and nearly 1 in 50 die as a result of the operation. For each additional case a hospital performs annually, the risk of IHM decreases by 30%.

Serious postoperative infections following resection of common solid tumors: outcomes, costs, and impact of hospital surgical volume

PURPOSE

Unlike infections related to chemotherapy-induced neutropenia, postoperative infections occurring in patients with solid malignancy remain largely understudied. Our aim is to evaluate the outcomes and the volume-outcomes relationship associated with postoperative infections following resection of common solid tumors.

METHODS

We used Texas Discharge Data to study patients undergoing resection of cancer of the lung, esophagus, stomach, pancreas, colon, or rectum from 01/2002 to 11/2006. From their billing records, we identified ICD-9 codes indicating a diagnosis of serious postoperative infection (SPI), i.e., bacteremia/sepsis, pneumonia, and wound infection, occurring during surgical admission or leading to readmission within 30 days of surgery. Using regression-based techniques, we estimated the impact of SPI on mortality, resource utilization, and costs, as well as the relationship between hospital volume and SPI, after adjusting for confounders and data clustering.

RESULTS

SPI occurred following 9.4 % of the 37,582 eligible tumor resections and was independently associated with nearly 12-fold increased odds of in-hospital mortality [95 % confidence interval (95 % CI), 7.2-19.5, P < 0.001]. Patients with SPI required six additional hospital days (95 % CI, 5.9-6.2) at an incremental cost of $16,991 (95 % CI, $16,495-$17,497). Patients who underwent resection at high-volume hospitals had a 16 % decreased odds of developing SPI than those at low-volume hospitals (P = 0.03).

CONCLUSIONS

Due to the substantial burden associated with SPI following common solid tumor resections, hospitals must identify more effective prophylactic measures to avert these potentially preventable infections. Additional volume-outcomes research is needed to identify infection prevention processes that can be transferred from high- to lower-volume providers.

Detecting postoperative hemorrhage or hematoma from administrative data: the performance of the AHRQ Patient Safety Indicator

BACKGROUND

Patient Safety Indicator (PSI) 9, "postoperative hemorrhage or hematoma" (PHH), of the US Agency for Healthcare Research and Quality has been considered for public quality of care reporting. We sought to evaluate its performance in detecting true complications.

METHODS

We conducted a retrospective, cross-sectional study of hospitalizations that met PSI 9 eligibility criteria. We sampled records flagged positive and negative by PSI 9 from a diverse set of 31 hospitals between February 2006, and June 2009. Trained abstractors reviewed medical records using standard instruments. We determined the sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values of the indicator.

RESULTS

Of 181 analyzable records flagged by PSI 9, 168 (93%; weighted PPV, 95% [95% confidence interval (CI), 90-98%]) involved an accurately coded event, but only 126 (70%; weighted PPV, 78% [95% CI, 58-90%]) represented true PHH. Thirty-two false positives involved only intraoperative hemorrhage. Among true positives, hypotension occurred in 28% and death attributed to the PHH in 4%. Thirty-two of 281 records flagged negative by PSI 9 (but enriched with questionably negative records) represented true PHH. The indicator's sensitivity was 42% (95% CI, 23-64%), specificity 99.9% (95% CI, 99.8-100%), and NPV 99.7% (95% CI, 99.0-99.9%). Modifying the indicator to include additional procedure codes improved both sensitivity (85% [95% CI, 67-94%]) and PPV (76% [95% CI, 60-88%]).

CONCLUSION

PSI 9 holds promise in detecting serious, possibly preventable complications. The indicator might be improved by specification of the 998.11 hemorrhage code to exclude purely intraoperative events and addition of procedure codes to the indicator's numerator criteria.

Sex and surgical outcomes and mortality after primary total knee arthroplasty: a risk-adjusted analysis

OBJECTIVE

Total knee arthroplasty (TKA) is a widely utilized and effective treatment option for end-stage knee osteoarthritis (OA). Knee OA is more prevalent among women compared to men, but there are limited data on the sex differences in surgical outcomes after primary TKA.

METHODS

Our sample consisted of all primary TKAs performed in Pennsylvania during the fiscal year 2002. We used International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify major complications and surgical revision. We used mixed-effects logistic regression models to examine the associations between sex and all-cause mortality, readmissions, and major surgical complications. We used proportional hazards models to assess the risk of surgical revision after index arthroplasty. We adjusted for race, age, hospital teaching status, hospital procedure volume, insurance status, and risk of mortality.

RESULTS

In 17,994 primary TKAs, there were 46 and 220 deaths at 30 days and 1 year, respectively. Compared to women, men had higher adjusted odds of 1-year mortality (odds ratio [OR] 1.48 [95% confidence interval (95% CI) 1.13-1.94]) after primary TKA. The overall odds of most major 30-day complications did not differ by sex except for surgical wound infections, which were higher in men compared to women (OR 1.31 [95% CI 1.08-1.60]); 30-day readmission was higher in men (OR 1.25 [95% CI 1.10-1.43]). Men had significantly higher rates of revision of index knee arthroplasty at 5 years (hazard ratio 1.20 [95% CI 1.05-1.36]) compared to women.

CONCLUSION

The higher rates of mortality, hospital readmissions, revision surgery, and wound infections in men undergoing elective primary TKA compared to women indicate there is a sex disparity in these outcomes.

Association between age and use of intensive care among surgical Medicare beneficiaries

PURPOSE

The purpose of this study is to determine the role age plays in use of intensive care for patients who have major surgery.

MATERIALS AND METHODS

Retrospective cohort study examining the association between age and admission to an intensive care unit (ICU) for all Medicare beneficiaries 65 years or older who had a hospitalization for 1 of 5 surgical procedures: esophagectomy, cystectomy, pancreaticoduodenectomy, elective open abdominal aortic aneurysm repair (open AAA), and elective endovascular abdominal aortic aneurysm repair (endo AAA) from 2004 to 2008. The primary outcome was admission to an ICU. Secondary outcomes were complications and hospital mortality. We used multilevel mixed-effects logistic regression to adjust for other patient and hospital-level factors associated with each outcome.

RESULTS

The percentage of hospitalized patients admitted to ICU ranged from 41.3% for endo AAA to 81.5% for open AAA. In-hospital mortality also varied, from 1.1% for endo AAA to 6.8% for esophagectomy. After adjusting for other factors, age was associated with admission to ICU for cystectomy (adjusted odds ratio [AOR], 1.56 [95% confidence interval, 1.36-1.78] for age 80-84+ years; 2.25 [1.85-2.75] for age 85+ years compared with age 65-69 years), pancreaticoduodenectomy (AOR, 1.26 [1.06-1.50] for age 80-84 years; 1.49 [1.11-1.99] for age 85+ years), and esophagectomy (AOR, 1.26 [1.02-1.55] for age 80-84 years; 1.28 [0.91-1.80] age 85+ years). Age was not associated with use of intensive care for open AAA or endo AAA. Older age was associated with increases in complication rates and in-hospital mortality for all 5 surgical procedures.

CONCLUSIONS

The association between age and use of intensive care was procedure specific. Complication rates and in-hospital mortality increased with age for all 5 surgical procedures.

Improving patient safety through the systematic evaluation of patient outcomes

Despite increased advocacy for patient safety and several large-scale programs designed to reduce preventable harm, most notably surgical checklists, recent data evaluating entire health systems suggests that we are no further ahead in improving patient safety and that hospital complications are no less frequent now than in the 1990s. We suggest that the failure to systematically measure patient safety is the reason for our limited pro gress. In addition to defining patient safety outcomes and describing their financial and clinical impact, we argue why the failure to implement patient safety measurement systems has compromised the ability to move the agenda forward. We also present an overview of how patient safety can be assessed and the strengths and weaknesses of each method and comment on some of the consequences created by the absence of a systematic measurement system.

Use of the Spine Adverse Events Severity System (SAVES) in patients with traumatic spinal cord injury. A comparison with institutional ICD-10 coding for the identification of acute care adverse events

STUDY DESIGN

Observational cohort comparison.

OBJECTIVES

To compare the previously validated Spine Adverse Events Severity system (SAVES) with International Classification of Diseases, Tenth Revision codes (ICD-10) codes for identifying adverse events (AEs) in patients with traumatic spinal cord injury (TSCI).

SETTING

Quaternary Care Spine Program.

METHODS

Patients discharged between 2006 and 2010 were identified from our prospective registry. Two consecutive cohorts were created based on the system used to record acute care AEs; one used ICD-10 coding by hospital coders and the other used SAVES data prospectively collected by a multidisciplinary clinical team. The ICD-10 codes were appropriately mapped to the SAVES. There were 212 patients in the ICD-10 cohort and 173 patients in the SAVES cohort. Analyses were adjusted to account for the different sample sizes, and the two cohorts were comparable based on age, gender and motor score.

RESULTS

The SAVES system identified twice as many AEs per person as ICD-10 coding. Fifteen unique AEs were more reliably identified using SAVES, including neuropathic pain (32 × more; P<0.001), urinary tract infections (1.4 × ; P<0.05), pressure sores (2.9 × ; P<0.001) and intra-operative AEs (2.3 × ; P<0.05). Eight of these 15 AEs more frequently identified by SAVES significantly impacted length of stay (P<0.05). Risk factors such as patient age and severity of paralysis were more reliably correlated to AEs collected through SAVES than ICD-10.

CONCLUSION

Implementation of the SAVES system for patients with TSCI captured more individuals experiencing AEs and more AEs per person compared with ICD-10 codes. This study demonstrates the utility of prospectively collecting AE data using validated tools.

Derivation and validation of automated electronic search strategies to extract Charlson comorbidities from electronic medical records

OBJECTIVE

To develop and validate automated electronic note search strategies (automated digital algorithm) to identify Charlson comorbidities.

PATIENTS AND METHODS

The automated digital algorithm was built by a series of programmatic queries applied to an institutional electronic medical record database. The automated digital algorithm was derived from secondary analysis of an observational cohort study of 1447 patients admitted to the intensive care unit from January 1 through December 31, 2006, and validated in an independent cohort of 240 patients. The sensitivity, specificity, and positive and negative predictive values of the automated digital algorithm and International Classification of Diseases, Ninth Revision (ICD-9) codes were compared with comprehensive medical record review (reference standard) for the Charlson comorbidities.

RESULTS

In the derivation cohort, the automated digital algorithm achieved a median sensitivity of 100% (range, 99%-100%) and a median specificity of 99.7% (range, 99%-100%). In the validation cohort, the sensitivity of the automated digital algorithm ranged from 91% to 100%, and the specificity ranged from 98% to 100%. The sensitivity of the ICD-9 codes ranged from 8% for dementia to 100% for leukemia, whereas specificity ranged from 86% for congestive heart failure to 100% for leukemia, dementia, and AIDS.

CONCLUSION

Our results suggest that search strategies that use automated electronic search strategies to extract Charlson comorbidities from the clinical notes contained within the electronic medical record are feasible and reliable. Automated digital algorithm outperformed ICD-9 codes in all the Charlson variables except leukemia, with greater sensitivity, specificity, and positive and negative predictive values.

Population-based estimates of transbronchial lung biopsy utilization and complications

BACKGROUND

Little is known about trends in the utilization or complication rates of transbronchial lung biopsy, particularly in community hospitals.

METHODS

We used the Healthcare Cost and Utilization Project Florida State Inpatient and State Ambulatory Surgical Databases to assess trends in transbronchial lung biopsy utilization in adults from 2000 to 2009. We subsequently calculated population based estimates of complications associated with transbronchial lung biopsy (iatrogenic pneumothorax and procedure-related hemorrhage) and identified characteristics associated with complications.

RESULTS

From 2000 to 2009, the age-adjusted rate of transbronchial biopsies per 100,000 adults in Florida decreased by 25% from 74 to 55 (p < 0.0001), despite stability in the overall utilization of bronchoscopy. Analysis of 82,059 procedures revealed that complications associated with transbronchial biopsy were uncommon and stable over the study period, with 0.97% (95% CI 0.94-1.01%) of procedures complicated by pneumothorax, 0.55% (95% CI 0.52-0.58%) by pneumothorax requiring chest tube placement, and 0.58% (95% CI 0.55-0.61%) by procedure-related hemorrhage. Patients with COPD (OR 1.51, 95% CI 1.31-1.75) and women (OR 1.32, 95% CI 1.15-1.52) were at increased risk for pneumothorax, while renal failure (OR 2.85, 95% CI 2.10-3.87), cirrhosis (OR 2.31, 95% CI 1.18-4.52), older age (OR 1.17, 95% CI 1.09-1.25) and female sex (OR 1.40, 95% CI 1.17-1.68) were associated with higher risk of procedure-related hemorrhage.

CONCLUSIONS

Utilization of transbronchial lung biopsy is decreasing relative to the overall use of bronchoscopy. Nevertheless, it remains a safe procedure with low risk of complications.

Examination of hospital characteristics and patient quality outcomes using four inpatient quality indicators and 30-day all-cause mortality

The study objective was to examine hospital mortality outcomes and structure using 2008 patient-level discharges from general community hospitals. Discharges from Florida administrative files were merged to the state mortality registry. A cross-sectional analysis of inpatient mortality was conducted using Inpatient Quality Indicators (IQIs) for acute myocardial infarction (AMI), congestive heart failure (CHF), stroke, pneumonia, and all-payer 30-day postdischarge mortality. Structural characteristics included bed size, volume, ownership, teaching status, and system affiliation. Outcomes were risk adjusted using 3M APR-DRG. Volume was inversely correlated with AMI, CHF, stroke, and 30-day mortality. Similarities and differences in the direction and magnitude of the relationship of structural characteristics to 30-day postdischarge and IQI mortality measures were observed. Hospital volume was inversely correlated with inpatient mortality outcomes. Other hospital characteristics were associated with some mortality outcomes. Further study is needed to understand the relationship between 30-day postdischarge mortality and hospital quality.

Accuracy of administrative coding in identifying hip and knee primary replacements and revisions

RATIONALE, AIMS AND OBJECTIVES

Hospital discharge notes can be used to identify rates of revisions in hip and knee arthroplasty surgeries if such administrative codes are accurate. In order to trust the data taken from the hospital discharge abstracts it is important to assess their reliability. The purpose of this study is to evaluate the accuracy of the administrative coding used in measuring revision rates for total hip and knee arthroplasty.

METHODS

Validation coding was determined by two orthopaedic surgery residents who reviewed the operative, radiological and discharge summaries in order to identify the revision rates for total hip and knee arthroplasty. A random sample of 637 patients from two tertiary care hospitals was studied. These patients had total hip or knee arthroplasty between 1996 and 2006. All of these patients had an International Classification of Disease (ICD)-9CM or ICD-10CM code indicating what procedure they had done. The validation reviewers were blinded to the administrative codes used. The sensitivity, specificity and positive and negative predictive values of the administrative codes for revision rates were measured.

RESULTS

Based on 1201 procedures performed on 637 patients, when comparing validation review versus hospital administrative chart coding for primary and revision surgeries of total hip and knee arthroplasty, the following data were obtained: for total hip arthroplasty sensitivity is 99%, specificity is 91%, positive predictive value is 91% and negative predictive value is 99%; for total knee arthroplasty sensitivity is 89%, specificity is 98%, positive predictive value is 97% and negative predictive value is 93%. The accuracy of ICD-9CM and ICD-10CM were 96% and 95%, respectively.

CONCLUSION

This study demonstrates that ICD-9CM and ICD-10CM codes can be used accurately when analysing hip and knee arthroplasty. This study was conducted in a large tertiary academic centre where a significant number of records analysts are employed; therefore, there should be little inter-hospital error. These results should help researchers understand the potential accuracy of classification for these procedures as part of an audit or quality assurance project.

A systematic review of validated methods for identifying venous thromboembolism using administrative and claims data

BACKGROUND

Venous thromboembolism (VTE) is a serious complication. Large claims databases can potentially identify the effects that medications have on VTE. The purpose of this study is to evaluate the evidence supporting the validity of VTE codes.

METHODS

A search of MEDLINE database is supplemented by manual searches of bibliographies of key relevant articles. We selected all studies in which a claim code was validated against a medical record. We reported the positive predictive value (PPV) for the VTE claim compared to the medical record.

RESULTS

Our search strategy yielded 345 studies, of which only 19 met our eligibility criteria. All of the studies reported on ICD-9 codes, but only two studies reported on pharmacy codes, and one study reported on procedure codes. The highest PPV (65%-95%) was reported for the combined use of ICD-9 codes 415 (pulmonary embolism), 451, and 453 (deep vein thrombosis) as a VTE event. If a specific event like DVT (PPV 24%-92%) or PE (PPV 31%-97%) was evaluated, the PPV was lower than when the combined events were examined. Studies that included patients after orthopedic surgery reported the highest PPV (96%-100%).

CONCLUSIONS

The use of ICD-9 415, 451, and 453 are appropriate for the identification of VTE in claims databases. The codes performed best when codes were evaluated in patients at higher risk of VTE.

Use of bone morphogenetic proteins in spinal fusion surgery for older adults with lumbar stenosis: trends, complications, repeat surgery, and charges

STUDY DESIGN

Retrospective cohort study of Medicare claims.

OBJECTIVE

Examine trends and patterns in the use of bone morphogenetic proteins (BMP) in surgery for lumbar stenosis; compare complications, reoperation rates, and charges for patients undergoing lumbar fusion with and without BMP.

SUMMARY OF BACKGROUND DATA

Small, randomized trials have demonstrated higher rates of solid fusion with BMP than with allograft bone alone, with few complications and, in some studies, reduced rates of revision surgery. However, complication and reoperation rates from large population-based cohorts in routine care are unavailable.

METHODS

We identified patients with a primary diagnosis of lumbar stenosis who had fusion surgery in 2003 or 2004 (n = 16,822). We identified factors associated with BMP use: major medical complications during the index hospitalization, rates of rehospitalization within 30 days, and rates of reoperation within 4 years of follow-up (through 2008).

RESULTS

Use of BMP increased rapidly, from 5.5% of fusion cases in 2003 to 28.1% of fusion cases in 2008. BMP use was greater among patients with previous surgery and among those having complex fusion procedures (combined anterior and posterior approach, or greater than 2 disc levels). Major medical complications, wound complications, and 30-day rehospitalization rates were nearly identical with or without BMP. Reoperation rates were also very similar, even after stratifying by previous surgery or surgical complexity, and after adjusting for demographic and clinical features. On average, adjusted hospital charges for operations involving BMP were about $15,000 more than hospital charges for fusions without BMP, though reimbursement under Medicare's Diagnosis-Related Group system averaged only about $850 more. Significantly fewer patients receiving BMP were discharged to a skilled nursing facility (15.9% vs. 19.0%, P < 0.001).

CONCLUSION

In this older population having fusion surgery for lumbar stenosis, uptake of BMP was rapid, and greatest among patients with prior surgery or having complex fusion procedures. BMP appeared safe in the perioperative period, with no increase in major medical complications. Use of BMP was associated with greater hospital charges but fewer nursing home discharges, and was not associated with reduced likelihood of reoperation.

The sensitivity of adverse event cost estimates to diagnostic coding error

OBJECTIVE

To examine the impact of diagnostic coding error on estimates of hospital costs attributable to adverse events.

DATA SOURCES

Original and reabstracted medical records of 9,670 complex medical and surgical admissions at 11 hospital corporations in Ontario from 2002 to 2004. Patient specific costs, not including physician payments, were retrieved from the Ontario Case Costing Initiative database.

STUDY DESIGN

Adverse events were identified among the original and reabstracted records using ICD10-CA (Canadian adaptation of ICD10) codes flagged as postadmission complications. Propensity score matching and multivariate regression analysis were used to estimate the cost of the adverse events and to determine the sensitivity of cost estimates to diagnostic coding error.

PRINCIPAL FINDINGS

Estimates of the cost of the adverse events ranged from $16,008 (metabolic derangement) to $30,176 (upper gastrointestinal bleeding). Coding errors caused the total cost attributable to the adverse events to be underestimated by 16 percent. The impact of coding error on adverse event cost estimates was highly variable at the organizational level.

CONCLUSIONS

Estimates of adverse event costs are highly sensitive to coding error. Adverse event costs may be significantly underestimated if the likelihood of error is ignored.

Marginal costs of hospital-acquired conditions: information for priority-setting for patient safety programmes and research

OBJECTIVE

To estimate the relative inpatient costs of hospital-acquired conditions.

METHODS

Patient level costs were estimated using computerized costing systems that log individual utilization of inpatient services and apply sophisticated cost estimates from the hospital's general ledger. Occurrence of hospital-acquired conditions was identified using an Australian 'condition-onset' flag for diagnoses not present on admission. These were grouped to yield a comprehensive set of 144 categories of hospital-acquired conditions to summarize data coded with ICD-10. Standard linear regression techniques were used to identify the independent contribution of hospital-acquired conditions to costs, taking into account the case-mix of a sample of acute inpatients (n = 1,699,997) treated in Australian public hospitals in Victoria (2005/06) and Queensland (2006/07).

RESULTS

The most costly types of complications were post-procedure endocrine/metabolic disorders, adding AU$21,827 to the cost of an episode, followed by MRSA (AU$19,881) and enterocolitis due to Clostridium difficile (AU$19,743). Aggregate costs to the system, however, were highest for septicaemia (AU$41.4 million), complications of cardiac and vascular implants other than septicaemia (AU$28.7 million), acute lower respiratory infections, including influenza and pneumonia (AU$27.8 million) and UTI (AU$24.7 million). Hospital-acquired complications are estimated to add 17.3% to treatment costs in this sample.

CONCLUSIONS

Patient safety efforts frequently focus on dramatic but rare complications with very serious patient harm. Previous studies of the costs of adverse events have provided information on 'indicators' of safety problems rather than the full range of hospital-acquired conditions. Adding a cost dimension to priority-setting could result in changes to the focus of patient safety programmes and research. Financial information should be combined with information on patient outcomes to allow for cost-utility evaluation of future interventions.

The accuracy of present-on-admission reporting in administrative data

OBJECTIVE

To test the accuracy of reporting present-on-admission (POA) and to assess whether POA reporting accuracy differs by hospital characteristics.

DATA SOURCES

We performed an audit of POA reporting of secondary diagnoses in 1,059 medical records from 48 California hospitals.

STUDY DESIGN

We used patient discharge data (PDD) to select records with secondary diagnoses that are powerful predictors of mortality and could potentially represent comorbidities or complications among patients who either had a primary procedure of a percutaneous transluminal coronary angioplasty or a primary diagnosis of acute myocardial infarction, community-acquired pneumonia, or congestive heart failure. We modeled the relationship between secondary diagnoses POA reporting accuracy (over-reporting and under-reporting) and hospital characteristics.

DATA COLLECTION

We created a gold standard from blind reabstraction of the medical records and compared the accuracy of the PDD against the gold standard.

PRINCIPAL FINDINGS

The PDD and gold standard agreed on POA reporting in 74.3 percent of records, with 13.7 percent over-reporting and 11.9 percent under-reporting. For-profit hospitals tended to overcode secondary diagnoses as present on admission (odds ratios [OR] 1.96; 95 percent confidence interval [CI] 1.11, 3.44), whereas teaching hospitals tended to undercode secondary diagnoses as present on admission (OR 2.61; 95 percent CI 1.36, 5.03).

CONCLUSIONS

POA reporting of secondary diagnoses is moderately accurate but varies by hospitals. Steps should be taken to improve POA reporting accuracy before using POA in hospital assessments tied to payments.

Population-based risk for complications after transthoracic needle lung biopsy of a pulmonary nodule: an analysis of discharge records

BACKGROUND

Because pulmonary nodules are found in up to 25% of patients undergoing computed tomography of the chest, the question of whether to perform biopsy is becoming increasingly common. Data on complications after transthoracic needle lung biopsy are limited to case series from selected institutions.

OBJECTIVE

To determine population-based estimates of risks for complications after transthoracic needle biopsy of a pulmonary nodule.

DESIGN

Cross-sectional analysis.

SETTING

The 2006 State Ambulatory Surgery Databases and State Inpatient Databases for California, Florida, Michigan, and New York from the Healthcare Cost and Utilization Project.

PATIENTS

15 865 adults who had transthoracic needle biopsy of a pulmonary nodule.

MEASUREMENTS

Percentage of biopsies complicated by hemorrhage, any pneumothorax, or pneumothorax requiring a chest tube, and adjusted odds ratios for these complications associated with various biopsy characteristics, calculated by using multivariate, population-averaged generalized estimating equations.

RESULTS

Although hemorrhage was rare, complicating 1.0% (95% CI, 0.9% to 1.2%) of biopsies, 17.8% (CI, 11.8% to 23.8%) of patients with hemorrhage required a blood transfusion. In contrast, the risk for any pneumothorax was 15.0% (CI, 14.0% to 16.0%), and 6.6% (CI, 6.0% to 7.2%) of all biopsies resulted in pneumothorax requiring a chest tube. Compared with patients without complications, those who experienced hemorrhage or pneumothorax requiring a chest tube had longer lengths of stay (P < 0.001) and were more likely to develop respiratory failure requiring mechanical ventilation (P = 0.020). Patients aged 60 to 69 years (as opposed to younger or older patients), smokers, and those with chronic obstructive pulmonary disease had higher risk for complications.

LIMITATIONS

Estimated risks may be inaccurate if coding of complications is incomplete. The analyzed databases contain little clinical detail (such as information on nodule characteristics or biopsy pathology) and cannot indicate whether performing the biopsy produced useful information.

CONCLUSION

Whereas hemorrhage is an infrequent complication of transthoracic needle lung biopsy, pneumothorax is common and often necessitates chest tube placement. These population-based data should help patients and physicians make more informed choices about whether to perform biopsy of a pulmonary nodule.

PRIMARY FUNDING SOURCE

Department of Veterans Affairs and National Cancer Institute.

Discovering disease associations by integrating electronic clinical data and medical literature

Electronic health record (EHR) systems offer an exceptional opportunity for studying many diseases and their associated medical conditions within a population. The increasing number of clinical record entries that have become available electronically provides access to rich, large sets of patients' longitudinal medical information. By integrating and comparing relations found in the EHRs with those already reported in the literature, we are able to verify existing and to identify rare or novel associations. Of particular interest is the identification of rare disease co-morbidities, where the small numbers of diagnosed patients make robust statistical analysis difficult. Here, we introduce ADAMS, an Application for Discovering Disease Associations using Multiple Sources, which contains various statistical and language processing operations. We apply ADAMS to the New York-Presbyterian Hospital's EHR to combine the information from the relational diagnosis tables and textual discharge summaries with those from PubMed and Wikipedia in order to investigate the co-morbidities of the rare diseases Kaposi sarcoma, toxoplasmosis, and Kawasaki disease. In addition to finding well-known characteristics of diseases, ADAMS can identify rare or previously unreported associations. In particular, we report a statistically significant association between Kawasaki disease and diagnosis of autistic disorder.

A comparison of comorbidities obtained from hospital administrative data and medical charts in older patients with pneumonia

Background

The use of comorbidities in risk adjustment for health outcomes research is frequently necessary to explain some of the observed variations. Medical charts reviews to obtain information on comorbidities is laborious. Increasingly, electronic health care databases have provided an alternative for health services researchers to obtain comorbidity information. However, the rates obtained from databases may be either over- or under-reported. This study aims to (a) quantify the agreement between administrative data and medical charts review across a set of comorbidities; and (b) examine the factors associated with under- or over-reporting of comorbidities by administrative data.

Methods

This is a retrospective cross-sectional study of patients aged 55 years and above, hospitalized for pneumonia at 3 acute care hospitals. Information on comorbidities were obtained from an electronic administrative database and compared with information from medical charts review. Logistic regression was performed to identify factors that were associated with under- or over-reporting of comorbidities by administrative data.

Results

The prevalence of almost all comorbidities obtained from administrative data was lower than that obtained from medical charts review. Agreement between comorbidities obtained from medical charts and administrative data ranged from poor to very strong (kappa 0.01 to 0.78). Factors associated with over-reporting of comorbidities were increased length of hospital stay, disease severity, and death in hospital. In contrast, those associated with under-reporting were number of comorbidities, age, and hospital admission in the previous 90 days.

Conclusions

The validity of using secondary diagnoses from administrative data as an alternative to medical charts for identification of comorbidities varies with the specific condition in question, and is influenced by factors such as age, number of comorbidities, hospital admission in the previous 90 days, severity of illness, length of hospitalization, and whether inhospital death occurred. These factors need to be taken into account when relying on administrative data for comorbidity information.

Derivation and validation of automated electronic search strategies to identify pertinent risk factors for postoperative acute lung injury

OBJECTIVE

To develop and validate time-efficient automated electronic search strategies for identifying preoperative risk factors for postoperative acute lung injury.

PATIENTS AND METHODS

This secondary analysis of a prospective cohort study included 249 patients undergoing high-risk surgery between November 1, 2005, and August 31, 2006. Two independent data-extraction strategies were compared. The first strategy used a manual review of medical records and the second a Web-based query-building tool. Web-based searches were derived and refined in a derivation cohort of 83 patients and subsequently validated in an independent cohort of 166 patients. Agreement between the 2 search strategies was assessed with percent agreement and Cohen κ statistics.

RESULTS

Cohen κ statistics ranged from 0.34 (95% confidence interval, 0.00-0.86) for amiodarone to 0.85 for cirrhosis (95% confidence interval, 0.57-1.00). Agreement between manual and automated electronic data extraction was almost complete for 3 variables (diabetes mellitus, cirrhosis, H(2)-receptor antagonists), substantial for 3 (chronic obstructive pulmonary disease, proton pump inhibitors, statins), moderate for gastroesophageal reflux disease, and fair for 2 variables (restrictive lung disease and amiodarone). Automated electronic queries outperformed manual data collection in terms of sensitivities (median, 100% [range, 77%-100%] vs median, 87% [range, 0%-100%]). The specificities were uniformly high (≥ 96%) for both search strategies.

CONCLUSION

Automated electronic query building is an iterative process that ultimately results in accurate, highly efficient data extraction. These strategies may be useful for both clinicians and researchers when determining the risk of time-sensitive conditions such as postoperative acute lung injury.

Importance of health system context for evaluating utilization patterns across systems

Measuring health services provided to patients can be difficult when patients see providers across multiple health systems and all visits are rarely captured in a single data source covering all systems where patients receive care. Studies that account for only one system will omit the out-of-system health-care use at the patient level. Combining data across systems and comparing utilization patterns across health systems creates complications for both aggregation and accuracy because data-generating processes (DGPs) tend to vary across systems. We develop a hybrid methodology for aggregation across systems, drawing on the strengths of the DGP in each system, and demonstrate its validity for answering research questions requiring cross-system assessments of health-care utilization. Positive and negative predictive probabilities can be useful to assess the impact of the hybrid methodology. We illustrate these issues comparing public sector (administrative records from the US Department of Veterans Affairs system) and private sector (billing records from the US Medicare system) patient level data to identify primary-care utilization. Understanding the context of a particular health system and its effect on the DGP is important in conducting effective valid evaluations.

Comparative effectiveness research and medical informatics

As is the case for environmental, ecological, astronomical, and other sciences, medical practice and research finds itself in a tsunami of data. This data deluge, due primarily to the introduction of digitalization in routine medical care and medical research, affords the opportunity for improved patient care and scientific discovery. Medical informatics is the subdiscipline of medicine created to make greater use of information in order to improve healthcare. The 4 areas of medical informatics research (information access, structure, analysis, and interaction) are used as a framework to discuss the overlap in information needs of comparative effectiveness research and potential contributions of medical informatics. Examples of progress from the medical informatics literature and the Veterans Affairs Healthcare System are provided.

Complications rates of non-oncologic urologic procedures in population-based data: a comparison to published series

PURPOSE

Published single institutional case series are often performed by one or more surgeons with considerable expertise in specific procedures. The reported incidence of complications in these series may not accurately reflect community-based practice. We sought to compare complication and mortality rates following urologic procedures derived from population-based data to those of published single-institutional case series.

MATERIALS AND METHODS

In-hospital mortality and complications of common urologic procedures (percutaneous nephrostomy, ureteropelvic junction obstruction repair, ureteroneocystostomy, urethral repair, artificial urethral sphincter implantation, urethral suspension, transurethral resection of the prostate, and penile prosthesis implantation) reported in the U.S.'s National Inpatient Sample of the Healthcare Cost and Utilization Project were identified. Rates were then compared to those of published single-institution series using statistical analysis.

RESULTS

For 7 of the 8 procedures examined, there was no significant difference in rates of complication or mortality between published studies and our population-based data. However, for percutaneous nephrostomy, two published single-center series had significantly lower mortality rates (p < 0.001). The overall rate of complications in the population-based data was higher than published single or select multi-institutional data for percutaneous nephrostomy performed for urinary obstruction (p < 0.001).

CONCLUSIONS

If one assumes that administrative data does not suffer from under reporting of complications then for some common urological procedures, complication rates between population-based data and published case series seem comparable. Endorsement of mandatory collection of clinical outcomes is likely the best way to appropriately counsel patients about the risks of these common urologic procedures.

Does aspirin have a role in venous thromboembolism prophylaxis in total knee arthroplasty patients?

The objectives of this study were to compare the risk of venous thromboembolism (VTE), bleeding, surgical site infection, and mortality in patients receiving aspirin or guideline-approved VTE prophylactic therapies (warfarin, low-molecular-weight heparins, synthetic pentasaccharides) in total knee arthroplasty (TKA). We analyzed clinical and administrative data from 93,840 patients who underwent primary TKA at 307 US hospitals over a 24-month period. Fifty-one thousand nine hundred twenty-three (55%) patients received warfarin, 37,198 (40%) received injectable agents, and 4719 (5%) received aspirin. After adjustment for patient and hospital factors, patients who received aspirin VTE prophylaxis (VTEP) had lower odds for thromboembolism compared to warfarin patients but with similar odds compared with injectable VTEP; there were no differences in risk of bleeding, infection, or mortality after adjustment. Our results suggest that aspirin, when used in conjunction with other clinical care protocols, may be effective VTEP for certain TKA patients.

Reinfection following initial cerebrospinal fluid shunt infection

OBJECT

Significant variation exists in the surgical and medical management of CSF shunt infection. The objectives of this study were to determine CSF shunt reinfection rates following initial CSF shunt infection in a large patient cohort and to determine management, patient, hospital, and surgeon factors associated with CSF shunt reinfection.

METHODS

This retrospective cohort study included children who were in the Pediatric Health Information System (PHIS) database, who ranged in age from 0 to 18 years, and who underwent uncomplicated initial CSF shunt placement in addition to treatment for initial CSF shunt infection between January 1, 2001, and December 31, 2008. The outcome was CSF shunt reinfection within 6 months. The main predictor variable of interest was surgical approach to treatment of first infection, which was determined for 483 patients. Covariates included patient, hospital, surgeon, and other management factors.

RESULTS

The PHIS database includes 675 children with initial CSF shunt infection. Surgical approach to treatment of the initial CSF shunt infection was determined for 483 children (71.6%). The surgical approach was primarily shunt removal/new shunt placement (in 286 children [59.2%]), but a substantial number underwent externalization (59 children [12.2%]), of whom a subset went on to have the externalized shunt removed and a new shunt placed (17 children [3.5% overall]). Other approaches included nonsurgical management (64 children [13.3%]) and complete shunt removal without shunt replacement (74 children [15.3%]). The 6-month reinfection rate was 14.8% (100 of 675 patients). The median time from infection to reinfection was 21 days (interquartile range [IQR] 5-58 days). Children with reinfection had less time between shunt placement and initial infection (median 50 vs 79 days, p = 0.06). No differences between those with and without reinfection were seen in patient factors (patient age at either shunt placement or initial infection, sex, race/ethnicity, payer, indication for shunt, number of comorbidities, distal shunt location, and number of shunt revisions at first infection); hospital volume; surgeon volume; or other management factors (for example, duration of intravenous antibiotic use). Nonsurgical management was associated with reinfection, and complete shunt removal was negatively associated with reinfection. However, reinfection rates did not differ between the 2 most common surgical approaches: shunt removal/new shunt placement (44 [15.4%] of 286; 95% CI 11.4%-20.1%) and externalization (total 12 [20.3%] of 59; 95% CI 11.0%-32.8%). Externalization followed by shunt removal/new shunt placement (5 [29.4%] of 17; 95% CI 10.3%-56.0%) and nonsurgical management (15 [23.4%] of 64; 95% CI 13.8%-35.7%) had higher, but nonstatistically significant, reinfection rates. The length of stay was shorter for nonsurgical management.

CONCLUSIONS

Surgical approach to treatment of initial CSF shunt infection was not associated with reinfection in this large cohort of patients.

Signs of the 2009 influenza pandemic in the New York-Presbyterian Hospital electronic health records

Background

In June of 2009, the World Health Organization declared the first influenza pandemic of the 21^st century, and by July, New York City's New York-Presbyterian Hospital (NYPH) experienced a heavy burden of cases, attributable to a novel strain of the virus (H1N1pdm).

Methods and Results

We present the signs in the NYPH electronic health records (EHR) that distinguished the 2009 pandemic from previous seasonal influenza outbreaks via various statistical analyses. These signs include (1) an increase in the number of patients diagnosed with influenza, (2) a preponderance of influenza diagnoses outside of the normal flu season, and (3) marked vaccine failure. The NYPH EHR also reveals distinct age distributions of patients affected by seasonal influenza and the pandemic strain, and via available longitudinal data, suggests that the two may be associated with distinct sets of comorbid conditions as well. In particular, we find significantly more pandemic flu patients with diagnoses associated with asthma and underlying lung disease. We further observe that the NYPH EHR is capable of tracking diseases at a resolution as high as particular zip codes in New York City.

Conclusion

The NYPH EHR permits early detection of pandemic influenza and hypothesis generation via identification of those significantly associated illnesses. As data standards develop and databases expand, EHRs will contribute more and more to disease detection and the discovery of novel disease associations.

Care pathways and patient safety: key concepts, patient outcomes and related interventions

Although care pathways often target efficiency of care through mapping and standardizing care processes, care can also be improved by reducing patient safety events, such as complications. In this paper, the authors review key concepts and literature relevant to parallels between patient safety and pathway interventions, as well as patient safety issues that should be considered in pathway development and implementation. Both care pathways and patient safety interventions are more likely to be effective when based on a theoretical framework related to human or systems factors or behaviour. Care pathways can target patient safety outcomes, but can also produce new hazards, through applying standards too broadly, reducing adaptability to complex situations or changing care processes in unforeseen ways. Both pathways and safety interventions must also be efficient and consider the opportunity costs of the time needed for providers to implement the intervention. Further research should explore how best to standardize care when needed, while evaluating how best to prevent and monitor hazards, allow for innovation and adaptability to customize care when appropriate, and continue to develop new methods for improving quality.

Comparing the effectiveness of computerized adverse drug event monitoring systems to enhance clinical decision support for hospitalized patients

OBJECTIVE

Performance of computerized adverse drug event (ADE) monitoring of electronic health records through a prospective ADE Monitor and ICD9-coded clinical text review operating independently and simultaneously on the same patient population for a 10-year period are compared. Requirements are compiled for clinical decision support in pharmacy systems to enhance ADE detection.

METHODS

A large tertiary care facility in Utah, with a history of quality improvement using its advanced hospital information system, was leveraged in this study. ICD9-based review of clinical charts (ICD9 System) was compared quantitatively and qualitatively to computer-assisted pharmacist-verified ADEs (ADE Monitor). The capture-recapture statistical method was applied to the data to determine an estimated prevalence of ADEs.

RESULTS

A total estimated ADE prevalence of 5.53% (13,420/242,599) was calculated, with the ICD9 system identifying 2,604 or 19.4%, and the ADE monitor 3,386 or 25.2% of all estimated ADEs. Both methods commonly identified 4.9% of all estimated ADEs and matched 62.0% of the time, each having its strength in detecting a slightly different domain of ADEs. 70% of the ADE documentation in the clinical notes was found in the discharge summaries.

CONCLUSION

Coupled with spontaneous reporting, computerized methods account for approximately half of all ADEs that can currently be detected. To enhance ADE monitoring and patient safety in a hospitalized setting, pharmacy information systems should incorporate prospective structuring and coding of the text in clinical charts and using that data alongside computer-generated alerts of laboratory results and drug orders. Natural language processing can aid computerized detection by automating the coding, in real-time, of physician text from clinical charts so that decision support rules can be created and applied. New detection strategies and enhancements to existing systems should be researched to enhance the detection of ADEs since approximately half are not currently detected.

The rising incidence of acromioplasty

BACKGROUND

Acromioplasty is considered a technically simple procedure but has become controversial with regard to its indications and therapeutic value.

METHODS

Two complementary databases were used to ascertain the frequency of acromioplasty over a recent span of time. In Part A, the New York Statewide Planning and Research Cooperative System (SPARCS) ambulatory surgery database was searched from 1996 to 2006 to identify all ambulatory surgery acromioplasties as well as all orthopaedic ambulatory surgery procedures. In Part B, the American Board of Orthopaedic Surgery (ABOS) database was searched from 1999 to 2008 to identify all arthroscopic acromioplasties as well as all orthopaedic procedures.

RESULTS

Part A revealed that in 1996 there were 5571 acromioplasties in New York State, representing a population incidence of 30.0 per 100,000. In 2006 there were 19,743 acromioplasties, representing a population incidence of 101.9 per 100,000. Over these eleven years, the volume of acromioplasties increased by 254.4%, compared with only a 78.3% increase in the volume of all orthopaedic ambulatory surgery procedures. In 2006, as compared with 1996, patients were 2.4 times more likely to have an acromioplasty compared with all other orthopaedic ambulatory procedures (p < 0.0001). Part B revealed that, in 1999, a mean of 2.6 arthroscopic acromioplasties were reported per candidate for Board certification. In 2008 a mean of 6.3 arthroscopic acromioplasties per candidate were reported. Over these ten years, the mean number of arthroscopic acromioplasties reported increased by 142.3%, compared with only a 13.0% increase in the mean number of all orthopaedic surgery procedures. In 2008, as compared with 1999, candidates were 2.2 times more likely to report an arthroscopic acromioplasty compared with all other orthopaedic procedures (p < 0.0001).

CONCLUSIONS

There has been a substantial increase in the overall volume and the population-based incidence of acromioplasties in recent years on both the state and national levels in the United States. The reasons for this increase have yet to be determined and are likely multifactorial, with patient-based, surgeon-based, and systems-based factors all playing a role.

Did duty hour reform lead to better outcomes among the highest risk patients?

BACKGROUND

Earlier work demonstrated that ACGME duty hour reform did not adversely affect mortality, with slight improvement noted among specific subgroups.

OBJECTIVE

To determine whether resident duty hour reform differentially affected the mortality risk of high severity patients or patients who experienced post-operative complications (failure-to-rescue).

DESIGN

Observational study using interrupted time series analysis with data from July 1, 2000 - June 30, 2005. Fixed effects logistic regression was used to examine the change in the odds of mortality or failure-to-rescue (FTR) in more versus less teaching-intensive hospitals before and after duty hour reform.

PARTICIPANTS

All unique Medicare patients (n = 8,529,595) admitted to short-term acute care non-federal hospitals and all unique VA patients (n = 318,636 patients) with principal diagnoses of acute myocardial infarction, congestive heart failure, gastrointestinal bleeding, stroke or a DRG classification of general, orthopedic or vascular surgery.

MEASUREMENTS AND MAIN RESULTS

We measured mortality within 30 days of hospital admission and FTR, measured by death among patients who experienced a surgical complication. The odds of mortality and FTR generally changed at similar rates for higher and lower risk patients in more vs. less teaching intensive hospitals. For example, comparing the mortality risk for the 10% of Medicare patients with highest risk to the other 90% of patients in post-reform year 1 for combined medical an OR of 1.01 [95% CI 0.90, 1.13], for combined surgical an OR of 0.91 [95% CI 0.80, 1.04], and for FTR an OR of 0.94 [95% CI 0.80, 1.09]. Findings were similar in year 2 for both Medicare and VA. The two exceptions were a relative increase in mortality for the highest risk medical (OR 1.63 [95% CI 1.08, 2.46]) and a relative decrease in the high risk surgical patients within VA in post-reform year 1 (OR 0.52 [95% CI 0.29, 0.96]).

CONCLUSIONS

ACGME duty hour reform was not associated with any consistent improvements or worsening in mortality or failure-to-rescue rates for high risk medical or surgical patients.

Infection rates following initial cerebrospinal fluid shunt placement across pediatric hospitals in the United States. Clinical article

OBJECT

Reported rates of CSF shunt infection vary widely across studies. The study objective was to determine the CSF shunt infection rates after initial shunt placement at multiple US pediatric hospitals. The authors hypothesized that infection rates between hospitals would vary widely even after adjustment for patient, hospital, and surgeon factors.

METHODS

This retrospective cohort study included children 0-18 years of age with uncomplicated initial CSF shunt placement performed between January 1, 2001, and December 31, 2005, and recorded in the Pediatric Health Information System (PHIS) longitudinal administrative database from 41 children's hospitals. For each child with 24 months of follow-up, subsequent CSF shunt infections and procedures were determined.

RESULTS

The PHIS database included 7071 children with uncomplicated initial CSF shunt placement during this time period. During the 24 months of follow-up, these patients had a total of 825 shunt infections and 4434 subsequent shunt procedures. Overall unadjusted 24-month CSF shunt infection rates were 11.7% per patient and 7.2% per procedure. Unadjusted 24-month cumulative incidence rates for each hospital ranged from 4.1 to 20.5% per patient and 2.5-12.3% per procedure. Factors significantly associated with infection (p < 0.05) included young age, female sex, African-American race, public insurance, etiology of intraventricular hemorrhage, respiratory complex chronic condition, subsequent revision procedures, hospital volume, and surgeon case volume. Malignant lesions and trauma as etiologies were protective. Infection rates for each hospital adjusted for these factors decreased to 8.8-12.8% per patient and 1.4-5.3% per procedure.

CONCLUSIONS

Infections developed in > 11% of children who underwent uncomplicated initial CSF shunt placements within 24 months. Patient, hospital, and surgeon factors contributed somewhat to the wide variation in CSF shunt infection rates across hospitals. Additional factors may contribute to variation in CSF shunt infection rates between centers, but further study is needed. Benchmarking and future prospective multicenter studies of CSF shunt infection will need to incorporate these and other patient, hospital, and surgeon factors.

Determining perioperative complications associated with vaginal hysterectomy: code classification versus chart review

BACKGROUND

Improvement in outcomes after vaginal hysterectomy (VH) requires accurate identification of complications. We hypothesized that coded data, commonly used to determine morbidity, would miss more complications than chart review would.

STUDY DESIGN

Medical records of women who underwent VH from January 2004 through December 2005 were reviewed for cardiac or respiratory arrest, congestive heart failure, pulmonary edema, pulmonary embolism, urinary tract infection, ureteral obstruction, hemorrhage, and delirium. Complications were identified with use of coded data, in which diagnoses were classified with a modification of the Hospital Adaptation of the International Classification of Diseases.

RESULTS

Records of 712 patients were reviewed. Of the 161 complications identified, 158 (98.1%) were identified through chart review and 48 (29.8%) through coded data. Codes captured all diagnoses of cardiac arrest, respiratory arrest, and pulmonary embolism but missed other complications.

CONCLUSIONS

Codes captured life-threatening complications, but other complications were underestimated or missed entirely. Reliance on coded data for outcomes assessments can be misleading and should be combined with other methods to maximize validity.

Hospital teaching intensity, patient race, and surgical outcomes

OBJECTIVES

To determine if the lower mortality often observed in teaching-intensive hospitals is because of lower complication rates or lower death rates after complications (failure to rescue) and whether the benefits at these hospitals accrue equally to white and black patients, since black patients receive a disproportionate share of their care at teaching-intensive hospitals.

DESIGN

A retrospective study of patient outcomes and teaching intensity using logistic regression models, with and without adjusting for hospital fixed and random effects.

SETTING

Three thousand two hundred seventy acute care hospitals in the United States.

PATIENTS

Medicare claims on general, orthopedic, and vascular surgery admissions in the United States for 2000-2005 (N = 4,658,954 unique patients).

MAIN OUTCOME MEASURES

Thirty-day mortality, in-hospital complications, and failure to rescue (the probability of death following complications).

RESULTS

Combining all surgeries, compared with nonteaching hospitals, patients at very major teaching hospitals demonstrated a 15% lower odds of death (P < .001), no difference in complications, and a 15% lower odds of death after complications (failure to rescue) (P < .001). These relative benefits associated with higher resident-to-bed ratio were not experienced by black patients, for whom the odds of mortality and failure to rescue were similar at teaching and nonteaching hospitals, a pattern that is significantly different from that of white patients (P < .001).

CONCLUSIONS

Survival after surgery is higher at hospitals with higher teaching intensity. Improved survival is because of lower mortality after complications (better failure to rescue) and generally not because of fewer complications. However, this better survival and failure to rescue at teaching-intensive hospitals is seen for white patients, not for black patients.

The Risk and Consequences of Clinical Miscoding Due to Inadequate Medical Documentation: A Case Study of the Impact on Health Services Funding

As coded clinical data are used in a variety of areas (e.g. health services funding, epidemiology, health sciences research), coding errors have the potential to produce far-reaching consequences. In this study the causes and consequences of miscoding were reviewed. In particular, the impact of miscoding due to inadequate medical documentation on hospital funding was examined. Appropriate reimbursement of hospital revenue in the casemix-based (output-based) funding system in the state of Victoria, Australia relies upon accurate, comprehensive, and timely clinical coding. In order to assess the reliability of these data in a Melbourne tertiary hospital, this study aimed to: (a) measure discrepancies in clinical code assignment; (b) identify resultant Diagnosis Related Group (DRG) changes; (c) identify revenue shifts associated with the DRG changes; (d) identify the underlying causes of coding error and DRG change; and (e) recommend strategies to address the aforementioned. An internal audit was conducted on 752 surgical inpatient discharges from the hospital within a six-month period. In a blind audit, each episode was re-coded. Comparisons were made between the original codes and the auditor-assigned codes, and coding errors were grouped and statistically analysed by categories. Changes in DRGs and weighted inlier-equivalent separations (WIES) were compared and analysed, and underlying factors were identified. Approximately 16% of the 752 cases audited reflected a DRG change, equating to a significant revenue increase of nearly AU$575,300. Fifty-six percent of DRG change cases were due to documentation issues. Incorrect selection or coding of the principal diagnosis accounted for a further 13% of the DRG changes, and missing additional diagnosis codes for 29%.The most significant of the factors underlying coding error and DRG change was poor quality of documentation. It was concluded that the auditing process plays a critical role in the identification of causes of coding inaccuracy and, thence, in the improvement of coding accuracy in routine disease and procedure classification and in securing proper financial reimbursement.

The economic value of professional nursing

BACKGROUND

Improved understanding of the economic value of registered nurse services can help inform staffing decisions and policies.

OBJECTIVES

To quantify the economic value of professional nursing.

METHODS

We synthesize findings from the literature on the relationship between registered nurse staffing levels and nursing-sensitive patient outcomes in acute care hospitals. Using hospital discharge data to estimate incidence and cost of these patient outcomes together with productivity measures, we estimate the economic implications of changes in registered nurse staffing levels.

SUBJECTS

Medical and surgical patients in nonfederal acute care hospitals. Data come from a literature review, and hospital discharge data from the 2005 Nationwide Inpatient Sample.

MEASURES

Patient nosocomial complications, healthcare expenditures, and national productivity.

RESULTS

As nurse staffing levels increase, patient risk of nosocomial complications and hospital length of stay decrease, resulting in medical cost savings, improved national productivity, and lives saved.

CONCLUSIONS

Only a portion of the services that professional nurses provide can be quantified in pecuniary terms, but the partial estimates of economic value presented illustrate the economic value to society of improved quality of care achieved through higher staffing levels.

Validity of selected AHRQ patient safety indicators based on VA National Surgical Quality Improvement Program data

OBJECTIVES

To examine the criterion validity of the Agency for Health Care Research and Quality (AHRQ) Patient Safety Indicators (PSIs) using clinical data from the Veterans Health Administration (VA) National Surgical Quality Improvement Program (NSQIP).

DATA SOURCES

Fifty five thousand seven hundred and fifty two matched hospitalizations from 2001 VA inpatient surgical discharge data and NSQIP chart-abstracted data.

STUDY DESIGN

We examined the sensitivities, specificities, positive predictive values (PPVs), and positive likelihood ratios of five surgical PSIs that corresponded to NSQIP adverse events. We created and tested alternative definitions of each PSI.

DATA COLLECTION

FY01 inpatient discharge data were merged with 2001 NSQIP data abstracted from medical records for major noncardiac surgeries.

PRINCIPAL FINDINGS

Sensitivities were 19-56 percent for original PSI definitions; and 37-63 percent using alternative PSI definitions. PPVs were 22-74 percent and did not improve with modifications. Positive likelihood ratios were 65-524 using original definitions, and 64-744 using alternative definitions. "Postoperative respiratory failure" and "postoperative wound dehiscence" exhibited significant increases in sensitivity after modifications.

CONCLUSIONS

PSI sensitivities and PPVs were moderate. For three of the five PSIs, AHRQ has incorporated our alternative, higher sensitivity definitions into current PSI algorithms. Further validation should be considered before most of the PSIs evaluated herein are used to publicly compare or reward hospital performance.

Impact of date stamping on patient safety measurement in patients undergoing CABG: experience with the AHRQ Patient Safety Indicators

Background

The Agency for Healthcare Research and Quality (AHRQ) Patient Safety Indicators (PSIs) provide information on hospital risk-adjusted rates for potentially preventable adverse events. Although designed to work with routine administrative data, it is unknown whether the PSIs can accurately distinguish between complications and pre-existing conditions. The objective of this study is to examine whether the AHRQ PSIs accurately measure hospital complication rates, using the data with present-on-admission (POA) codes to distinguish between complications and pre-existing conditions

Methods

Retrospective cohort study of patients undergoing isolated CABG surgery in California conducted using the 1998–2000 California State Inpatient Database. We calculated the positive predictive value of selected AHRQ PSIs using information from the POA as the gold standard, and the intra-class correlation coefficient to assess the level of agreement between the hospital risk-adjusted PSI rates with and without the information contained in the POA modifier.

Results

The false positive error rate, defined as one minus the positive predictive value, was greater than or equal to 20% for four of the eight PSIs examined: decubitus ulcer, failure-to-rescue, postoperative physiologic and metabolic derangement, and postoperative pulmonary embolism or deep venous thrombosis. Pairwise comparison of the hospital risk-adjusted PSI rates, with and without POA information, demonstrated almost perfect agreement for five of the eight PSI's. For decubitus ulcer, failure-to-rescue, and postoperative pulmonary embolism or DVT, the intraclass-correlation coefficient ranged between 0.63 to 0.79.

Conclusion

For some of the AHRQ Patient Safety Indicators, there are significant differences in the risk-adjusted rates of adverse events depending on whether the POA indicator is used to distinguish between pre-existing conditions and complications. The use of the POA indicator will increase the accuracy of the AHRQ PSIs as measures of adverse outcomes.

Racial disparities in the development of dysphagia after stroke: analysis of the California (MIRCal) and New York (SPARCS) inpatient databases

OBJECTIVES

To determine whether the proportion of patients with stroke experiencing dysphagia differs among racial groups and whether this relation can be explained by stroke type or severity.

DESIGN

Case-control study using California's Medical Information Reporting and New York's Statewide Planning and Research Cooperative System databases for 2002. Cases had primary diagnosis of cerebrovascular disease (International Classification of Disease, 9th Revision [ICD-9] codes 430-438.9, excluding transient [435-435.9] and late-effects [438-438.9]), and self-identified race was white, black, or Asian. Two comparison groups were selected: (1) Parkinson's disease (ICD-9 codes 332-332.1) and (2) oral cancer (ICD-9 codes 141-149).

SETTING

Inpatient admissions in the respective states.

PARTICIPANTS

Cases with primary diagnosis of cerebrovascular disease whose self-identified race was white, black, or Asian.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Dysphagia, defined by ICD-9 codes 787.2 (dysphagia), 507.0 (aspiration pneumonia), or presence of a feeding tube in the absence of a diagnosis of coma (Current Procedural Terminology codes 432.46 or 437.50 without ICD-9 code 780.01).

RESULTS

In the stroke group, the adjusted odds ratio (OR) with 95% confidence interval (CI) for dysphagia was significantly higher for Asians than whites in New York (OR=1.64; 95% CI, 1.50-1.79) and California (OR=1.69; 95% CI, 1.34-2.13). The adjusted OR was slightly but significantly higher for blacks than whites in New York (OR=1.15; 95% CI, 1.03-1.28), but not in California (OR=1.08; 95% CI, 0.97-1.19). No statistically significant differences among racial groups were found in patients with Parkinson's disease or oral cancer. Other factors strongly associated with dysphagia included hemiplegia (OR=2.19; 95% CI, 2.07-2.32) and aphasia (OR=1.97; 95% CI, 1.83-2.11).

CONCLUSIONS

Asians were more likely to have dysphagia after stroke. This association was statistically significant after adjusting for age, sex, stroke severity indicators, comorbidities, and stroke type.