David M. Studdert

Incidence and types of adverse events and negligent care in Utah and Colorado

BACKGROUND The ongoing debate on the incidence and types of iatrogenic injuries in American hospitals has been informed primarily by the Harvard Medical Practice Study, which analyzed hospitalizations in New York in 1984. The generalizability of these findings is unknown and has been questioned by other studies. OBJECTIVE We used methods similar to the Harvard Medical Practice Study to estimate the incidence and types of adverse events and negligent adverse events in Utah and Colorado in 1992. DESIGN AND SUBJECTS We selected a representative sample of hospitals from Utah and Colorado and then randomly sampled 15,000 nonpsychiatric 1992 discharges. Each record was screened by a trained nurse-reviewer for 1 of 18 criteria associated with adverse events. If > or =1 criteria were present, the record was reviewed by a trained physician to determine whether an adverse event or negligent adverse event occurred and to classify the type of adverse event. MEASURES The measures were adverse events and negligent adverse events. RESULTS Adverse events occurred in 2.9+/-0.2% (mean+/-SD) of hospitalizations in each state. In Utah, 32.6+/-4% of adverse events were due to negligence; in Colorado, 27.4+/-2.4%. Death occurred in 6.6+/-1.2% of adverse events and 8.8+/-2.5% of negligent adverse events. Operative adverse events comprised 44.9% of all adverse events; 16.9% were negligent, and 16.6% resulted in permanent disability. Adverse drug events were the leading cause of nonoperative adverse events (19.3% of all adverse events; 35.1% were negligent, and 9.7% caused permanent disability). Most adverse events were attributed to surgeons (46.1%, 22.3% negligent) and internists (23.2%, 44.9% negligent). CONCLUSIONS The incidence and types of adverse events in Utah and Colorado in 1992 were similar to those in New York State in 1984. Iatrogenic injury continues to be a significant public health problem. Improving systems of surgical care and drug delivery could substantially reduce the burden of iatrogenic injury.

Negligent Care and Malpractice Claiming Behavior in Utah and Colorado

BACKGROUND Previous studies relating the incidence of negligent medical care to malpractice lawsuits in the United States may not be generalizable. These studies are based on data from 2 of the most populous states (California and New York), collected more than a decade ago, during volatile periods in the history of malpractice litigation. OBJECTIVES The study objectives were (1) to calculate how frequently negligent and nonnegligent management of patients in Utah and Colorado in 1992 led to malpractice claims and (2) to understand the characteristics of victims of negligent care who do not or cannot obtain compensation for their injuries from the medical malpractice system. DESIGN We linked medical malpractice claims data from Utah and Colorado with clinical data from a review of 14,700 medical records. We then analyzed characteristics of claimants and nonclaimants using evidence from their medical records about whether they had experienced a negligent adverse event. MEASURES The study measures were negligent adverse events and medical malpractice claims. RESULTS Eighteen patients from our study sample filed claims: 14 were made in the absence of discernible negligence and 10 were made in the absence of any adverse event. Of the patients who suffered negligent injury in our study sample, 97% did not sue. Compared with patients who did sue for negligence occurring in 1992, these nonclaimants were more likely to be Medicare recipients (odds ratio [OR], 3.5; 95% CI [CI], 1.3 to 9.6), Medicaid recipients (OR, 3.6; 95% CI, 1.4 to 9.0), > or =75 years of age (OR, 7.0; 95% CI, 1.7 to 29.6), and low income earners (OR, 1.9; 95% CI, 0.9 to 4.2) and to have suffered minor disability as a result of their injury (OR, 6.3; 95% CI, 2.7 to 14.9). CONCLUSIONS The poor correlation between medical negligence and malpractice claims that was present in New York in 1984 is also present in Utah and Colorado in 1992. Paradoxically, the incidence of negligent adverse events exceeds the incidence of malpractice claims but when a physician is sued, there is a high probability that it will be for rendering nonnegligent care. The elderly and the poor are particularly likely to be among those who suffer negligence and do not sue, perhaps because their socioeconomic status inhibits opportunities to secure legal representation.

The Reliability of Medical Record Review for Estimating Adverse Event Rates

Context The Institute of Medicine report that caused concern about adverse events in hospitals relied on studies that used medical record review to identify adverse events. Many people question whether medical record reviews can accurately identify negligent adverse events. Contribution The following changes in the review process markedly reduced the rates of negligent adverse events: 1) increasing the number of reviewers from one to three and 2) requiring reviewers to be highly confident that an event was due to negligence. Implications Because review criteria can affect adverse event rates, the estimates cited by the Institute of Medicine could be inaccurate. The Editors Implicit judgments, based on medical record review, about adverse events caused by medical care have moderate to poor inter-rater reliability (1-7). However, the influential report on medical errors issued by the U.S. Institute of Medicine (IOM) in 2000 (8) relied on studies based on medical record review to estimate that 44 000 (9) to 98 000 (10) Americans die each year because of medical errors. These studies used one (9) or up to three (10) physician reviewers per record to detect adverse events. The IOM estimates are important because they have prompted health care providers and administrators to reduce errors and have influenced the U.S. research budget. We report details on the reliability of physician judgments about adverse events and negligent adverse events in the study from which the IOM derived its estimate of 44 000 error-related deaths per year (9). We also report the effects of varying criteria for reviewer confidence in and reviewer agreement about the presence of adverse events. Methods Data Sources This study was conducted as part of the Utah and Colorado Medical Practice Study (UCMPS) (5). In UCMPS, trained nurses reviewed medical records to identify 1 of 19 screening criteria that could indicate the presence of an adverse event. A trained physician then reviewed flagged records by using a structured chart abstraction form. Previously, the nurse review process was found to be a good screening tool, with a sensitivity of 84% (1). We began the current study with all 2868 records referred for physician review by nurse screeners from the original 15 000-record sample (5000 from Utah and 10 000 from Colorado) (Appendix Figure). Two physician investigators confirmed all adverse events detected during this initial review. As a result of this confirmation process, we eliminated 13 false-positive cases. We eliminated cases only if they failed to meet explicit criteria for an adverse event, not if there was a concern about the reviewers judgment regarding whether medical management caused the adverse event. Next, we randomly selected 500 of the 2868 records referred for physician review by nurse screeners (167 from Utah and 333 from Colorado), maintaining the original 1 to 2 ratio of Utah to Colorado records (Appendix Figure). The general characteristics of this sample are described elsewhere (5). Of these 500 records, 400 were randomly sampled from referred records that a single physician reviewer had previously judged to show no adverse events. Fifty records were randomly sampled from records initially found to show nonnegligent adverse events, and the remaining 50 were sampled from records initially judged to show negligent adverse events. This mix provided a sample similar to the one originally reviewed by the physicians. Record Review We completed three independent physician reviews of the original 500 medical records (not photocopies). The first was the original review for the UCMPS. The two subsequent physician reviews were conducted by physicians from the original UCMPS and by newly recruited physician reviewers who were trained in the same manner as the original UCMPS physician reviewers (5). Physicians could participate in more than one review; however, all reviewers were blinded to the purpose of these additional reviews, and none of them reviewed a record that they had previously reviewed. All physician reviewers used the same data form, which included the same definition of adverse event: an injury caused by medical management (rather than the disease process) that resulted in prolonged hospital stay or disability at discharge. Negligence was defined as care that fell below the standard expected of physicians in the community. Because judgments about adverse events may be complex, reviewers used a six-point confidence scale that has been used in previous studies (5, 6). We required a confidence score of at least four (>50% chance that medical management caused the adverse event) to indicate the presence of adverse events or negligent adverse events. For each of the three reviews, two investigators independently reviewed all detected adverse events to confirm that they met the study criteria. Statistical Analysis We calculated the rates of adverse events and negligent adverse events detected during each review. We report statistics for adverse events and negligent adverse events as the measure of inter-rater reliability. For all statistical analyses, we used SAS software, release 6.12 (SAS Institute, Inc., Cary, North Carolina). Role of the Funding Source The funding source contributed to the design of the study but had no role in conducting the study or in reporting its results. Results The first independent review of the study sample detected 64 adverse events; the second, 95; and the third, 86. Table 1 shows the agreement and disagreement among the three reviews. Comparisons between sets of reviews (review 1 compared with review 2, review 1 compared with review 3, and review 2 compared with review 3) demonstrated similar reliability. The statistics ranged from 0.40 to 0.41 (the lowest bound of the three 95% CIs was 0.30, and the highest was 0.51) for adverse events and from 0.19 to 0.24 (the lowest bound of the 95% CIs was 0.05, and the highest was 0.37) for negligent adverse events. The former is considered moderate; the latter is considered poor (11). We had hypothesized that reliability would increase as the reviewer confidence score required to indicate an adverse event decreased. However, when adverse events were defined as having a confidence score of two or greater instead of four or greater, the overall statistic for adverse events decreased slightly, from 0.41 to 0.37 (P = 0.19). Table 1. Number of Cases Resulting in Agreement and Disagreement among Three Sets of Reviews Different review strategies produced different estimates of the total number of adverse events and negligent adverse events. Increasing the confidence score to indicate the presence of an adverse event and increasing the degree of consensus between independent reviewers (agreement of one, two, or three reviewers) substantially affected adverse event rates in this sample of 500 records (Table 2). For example, if all three reviewers had a confidence score of four or greater, the adverse event rate would be 7.58% and the negligent adverse event rate would be 0.82%. If we required a score of four or greater on only one of three reviews to confirm the presence of an adverse event, the adverse event rate would be 37.68% and the negligent adverse event rate would be 15.13%. When the required confidence score was decreased to two, estimates among the three reviewers varied even more. Table 2. Adverse Event Rates Using Different Thresholds Discussion We found moderate to poor inter-rater reliability among physicians trying to identify adverse events and negligent adverse events by medical record review. Increasing the required levels of reviewer confidence to indicate the presence of an event or increasing the number of physician reviewers who detected an event resulted in markedly different event rates. Similar studies of medical record review have found almost identical reliability ( statistics of approximately 0.4 for both studies) (6, 7). Our study is limited because our data come from hospital records in two states that may not be generalizable to other geographic locations. Furthermore, we could not measure the validity of chart review because there is no true gold standard that avoids some type of implicit assessment. Despite the poor to moderate reliability of medical record review, each of the adverse events identified represents a potential opportunity for quality improvement (12, 13). Each case involving an adverse event may contain valuable information for improving patient safety. However, researchers should use caution when estimating incidence and prevalence of errors solely on the basis of these data. For example, the IOM used data from our larger study (9), which used medical record review, to estimate that 44 000 Americans die each year of preventable adverse events (or, to use the IOM term, medical errors) (8). Our results suggest that these estimates are sensitive to the reviewer consensus and confidence required to indicate the presence of adverse events. The estimate of 44 000 deaths could be approximately 50% lower if the study used to estimate that figure required independent agreement by two physician reviewers and could be 30% higher if the required reviewer confidence about the presence of an adverse event was lower (Table 2). We cannot quantify the reduction more precisely because the IOM figures are based on judgments about the number of preventable adverse events and our results are based on judgments about adverse events and negligent adverse events. The figures for error-related death reported by the IOM are imprecise. However, it is shortsighted to focus on the exact number of deaths and thereby ignore the vast additional research on errors and adverse events cited by the IOM (8, 14). Regardless of whether the number of annual U.S. deaths due to medical error is 30 000 or 300 000, the need to test interventions to reduce errors and adverse events is clear. Our findings suggest that persons and institutions interested

National Costs Of The Medical Liability System

Concerns about reducing the rate of growth of health expenditures have reignited interest in medical liability reforms and their potential to save money by reducing the practice of defensive medicine. It is not easy to estimate the costs of the medical liability system, however. This article identifies the various components of liability system costs, generates national estimates for each component, and discusses the level of evidence available to support the estimates. Overall annual medical liability system costs, including defensive medicine, are estimated to be

Relationship Between Malpractice Litigation Pressure and Rates of Cesarean Section and Vaginal Birth After Cesarean Section

55.6 billion in 2008 dollars, or 2.4 percent of total health care spending.

Patterns of Technical Error Among Surgical Malpractice Claims An Analysis of Strategies to Prevent Injury to Surgical Patients

Background:Since the 1990s, nationwide rates of vaginal birth after cesarean section (VBAC) have decreased sharply and rates of cesarean section have increased sharply. Both trends are consistent with clinical behavior aimed at reducing obstetricians’ exposure to malpractice litigation. Objective:To estimate the effects of malpractice pressure on rates of VBAC and cesarean section. Research Design, Subjects, Measures:We used state-level longitudinal mixed-effects regression models to examine data from the Natality Detail File on births in the United States (1991–2003). Malpractice pressure was measured by liability insurance premiums and tort reforms. Outcome measures were rates of VBAC, cesarean section, and primary cesarean section. Results:Malpractice premiums were positively associated with rates of cesarean section (&bgr; = 0.15, P = 0.02) and primary cesarean section (&bgr; = 0.16, P = 0.009), and negatively associated with VBAC rates (&bgr; = −0.35, P = 0.01). These estimates imply that a

Relationship between complaints and quality of care in New Zealand: a descriptive analysis of complainants and non-complainants following adverse events

10,000 decrease in premiums for obstetrician-gynecologists would be associated with an increase of 0.35 percentage points (1.45%) in the VBAC rate and decreases of 0.15 and 0.16 percentage points (0.7% and 1.18%) in the rates of cesarean section and primary cesarean section, respectively; this would correspond to approximately 1600 more VBACs, 6000 fewer cesarean sections, and 3600 fewer primary cesarean sections nationwide in 2003. Two types of tort reform—caps on noneconomic damages and pretrial screening panels—were associated with lower rates of cesarean section and higher rates of VBAC. Conclusions:The liability environment influences choice of delivery method in obstetrics. The effects are not large, but reduced litigation pressure would likely lead to decreases in the total number cesarean sections and total delivery costs.

Accountability sought by patients following adverse events from medical care: the New Zealand experience

Objective:To identify the most prevalent patterns of technical errors in surgery, and evaluate commonly recommended interventions in light of these patterns. Summary Background Data:The majority of surgical adverse events involve technical errors, but little is known about the nature and causes of these events. We examined characteristics of technical errors and common contributing factors among closed surgical malpractice claims. Methods:Surgeon reviewers analyzed 444 randomly sampled surgical malpractice claims from four liability insurers. Among 258 claims in which injuries due to error were detected, 52% (n = 133) involved technical errors. These technical errors were further analyzed with a structured review instrument designed by qualitative content analysis. Results:Forty-nine percent of the technical errors caused permanent disability; an additional 16% resulted in death. Two-thirds (65%) of the technical errors were linked to manual error, 9% to errors in judgment, and 26% to both manual and judgment error. A minority of technical errors involved advanced procedures requiring special training (“index operations”; 16%), surgeons inexperienced with the task (14%), or poorly supervised residents (9%). The majority involved experienced surgeons (73%), and occurred in routine, rather than index, operations (84%). Patient-related complexities—including emergencies, difficult or unexpected anatomy, and previous surgery—contributed to 61% of technical errors, and technology or systems failures contributed to 21%. Conclusions:Most technical errors occur in routine operations with experienced surgeons, under conditions of increased patient complexity or systems failure. Commonly recommended interventions, including restricting high-complexity operations to experienced surgeons, additional training for inexperienced surgeons, and stricter supervision of trainees, are likely to address only a minority of technical errors. Surgical safety research should instead focus on improving decision-making and performance in routine operations for complex patients and circumstances.

Results of a clinical trial on care improvement for the critically ill

Objectives: To estimate the proportion and characteristics of patients injured by medical care in New Zealand public hospitals who complain to an independent health ombudsman, the Health and Disability Commissioner (“the Commissioner”). Design: The percentage of injured patients who lodge complaints was estimated by linking the Commissioner’s complaints database to records reviewed in the New Zealand Quality of Healthcare Study (NZQHS). Bivariate and multivariate analyses investigated sociodemographic and socioeconomic differences between complainants and non-complainants. Setting: New Zealand public hospitals and the Office of the Commissioner in 1998. Population: Patients who lodged claims with the Commissioner (n = 398) and patients identified by the NZQHS as having suffered an adverse event who did not lodge a complaint with the Commissioner (n = 847). Main outcome measures: Adverse events, preventable adverse events, and complaints lodged with the Commissioner. Results: Among adverse events identified by the NZQHS, 0.4% (3/850) resulted in complaints; among serious, preventable adverse events 4% (2/48) resulted in complaints. The propensity of injured patients to complain increased steeply with the severity of the injury: odds of complaint were 11 times greater after serious permanent injuries than after temporary injuries, and 18 times greater after deaths. Odds of complaining were significantly lower for patients who were elderly (odds ratio (OR) 0.2, 95% confidence interval (CI) 0.1 to 0.4), of Pacific ethnicity (OR 0.3, 95% CI 0.1 to 0.9), or lived in the most deprived areas (OR 0.3, 95% CI 0.2 to 0.6). Conclusion: Most medical injuries never trigger a complaint to the Commissioner. Among complaints that are brought, severe and preventable injuries are common, offering a potentially valuable “window” on serious threats to patient safety. The relatively low propensity to complain among patients who are elderly, socioeconomically deprived, or of Pacific ethnicity suggests troubling disparities in access to and utilisation of complaints processes.

Strategies and Practices in Off-Label Marketing of Pharmaceuticals: A Retrospective Analysis of Whistleblower Complaints

Background: Unlike Canadas medical malpractice system, patients in New Zealand who are dissatisfied with the quality of their care may choose between 2 well-established medicolegal paths: one leads to monetary compensation and the other to nonmonetary forms of accountability. We compared the forms of accountability sought by patients and families in New Zealand who took different types of legal action following a medical injury. This study offers insights into the forms of accountability sought by injured patients and may help to inform tort-reform initiatives. Methods: We reviewed compensation claims submitted to the Accident Compensation Corporation (ACC), New Zealands national no-fault insurer, following injuries associated with admission to a public hospital in 1998 (n = 582). We also reviewed complaint letters (n = 254) submitted to the national Health and Disability Commissioner (HDC) that same year to determine the forms of accountability sought by injured patients. We used univariable and multivariable analyses to compare sociodemographic and socioeconomic characteristics of patients who sought nonmonetary forms of accountability with those of patients who claimed compensation. Results: Of 154 injured patients whose complaints were sufficiently detailed to allow coding, 50% sought corrective action to prevent similar harm to future patients (45% system change, 6% review of involved clinicians competence) and 40% wanted more satisfying communication (34% explanation, 10% apology). The odds that patients would seek compensation were significantly increased if they were in their prime working years (aged between 30 and 64 years) (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.14–2.41) or had a permanent disability as a result of their injury (OR 1.75, 95% CI 1.14–2.70). When injuries resulted in death, the odds of a compensation claim to the ACC were about one-eighth those of a complaint to the HDC (OR 0.13, 95% CI 0.08–0.23). Interpretation: Injured patients who pursue medicolegal action seek various forms of accountability. Compensation is important to some, especially when economic losses are substantial (e.g., with injury during prime working years or severe nonfatal injuries). However, others have purely nonmonetary goals, and ensuring alternative options for redress would be an efficient and effective response to their needs.