Liesi E. Hebert

Incidence of adverse events and negligence in hospitalized patients. Results of the Harvard Medical Practice Study I.

BACKGROUND As part of an interdisciplinary study of medical injury and malpractice litigation, we estimated the incidence of adverse events, defined as injuries caused by medical management, and of the subgroup of such injuries that resulted from negligent or substandard care. METHODS We reviewed 30,121 randomly selected records from 51 randomly selected acute care, nonpsychiatric hospitals in New York State in 1984. We then developed population estimates of injuries and computed rates according to the age and sex of the patients as well as the specialties of the physicians. RESULTS Adverse events occurred in 3.7 percent of the hospitalizations (95 percent confidence interval, 3.2 to 4.2), and 27.6 percent of the adverse events were due to negligence (95 percent confidence interval, 22.5 to 32.6). Although 70.5 percent of the adverse events gave rise to disability lasting less than six months, 2.6 percent caused permanently disabling injuries and 13.6 percent led to death. The percentage of adverse events attributable to negligence increased in the categories of more severe injuries (Wald test chi 2 = 21.04, P less than 0.0001). Using weighted totals, we estimated that among the 2,671,863 patients discharged from New York hospitals in 1984 there were 98,609 adverse events and 27,179 adverse events involving negligence. Rates of adverse events rose with age (P less than 0.0001). The percentage of adverse events due to negligence was markedly higher among the elderly (P less than 0.01). There were significant differences in rates of adverse events among categories of clinical specialties (P less than 0.0001), but no differences in the percentage due to negligence. CONCLUSIONS There is a substantial amount of injury to patients from medical management, and many injuries are the result of substandard care.

Annual incidence of Alzheimer disease in the United States projected to the years 2000 through 2050

Alzheimer disease will affect increasing numbers of people as baby boomers (persons born between 1946 and 1964) age. This work reports projections of the incidence of Alzheimer disease(AD) that will occur among older Americans in the future. Education adjusted age-specific incidence rates of clinically diagnosed probable AD were obtained from stratified random samples of residents 65 years of age and older in a geographically defined community. These rates were applied to U.S. Census Bureau projections of the total U.S. population by age and sex to estimate the number of people newly affected each year. The annual number of incident cases is expected to more than double by the midpoint of the twenty-first century: from 377,000 (95% confidence interval = 159,000–595,000) in 1995 to 959,000 (95% confidence interval = 140,000–1,778,000) in 2050. The proportion of new onset casess who are age 85 or older will increase from 40% in 1995 to 62% in 2050 when the youngest of the baby boomers will attain that age. Without progress in preventing or delaying onset of Alzheimer disease, both the number of people with Alzheimer disease and the proportion of the total population affected will increase substantially.

Vitamin E and vitamin C supplement use and risk of incident Alzheimer disease.

Oxidative stress may play a role in neurologic disease. The present study examined the relation between use of vitamin E and vitamin C and incident Alzheimer disease in a prospective study of 633 persons 65 years and older. A stratified random sample was selected from a disease-free population. At baseline, all vitamin supplements taken in the previous 2 weeks were identified by direct inspection. After an average follow-up period of 4.3 years, 91 of the sample participants with vitamin information met accepted criteria for the clinical diagnosis of Alzheimer disease. None of the 27 vitamin E supplement users had Alzheimer disease compared with 3.9 predicted based on the crude observed incidence among nonusers (p = 0.04) and 2.5 predicted based on age, sex, years of education, and length of follow-up interval (p = 0.23). None of the 23 vitamin C supplement users had Alzheimer disease compared with 3.3 predicted based on the crude observed incidence among nonusers (p = 0.10) and 3.2 predicted adjusted for age, sex, education, and follow-up interval (p = 0.04). There was no relation between Alzheimer disease and use of multivitamins. These data suggest that use of the higher-dose vitamin E and vitamin C supplements may lower the risk of Alzheimer disease.

Level of education and change in cognitive function in a community population of older persons

In a community population of persons over the age of 65, cognitive function was assessed using brief performance tests on two occasions 3 years apart. Those with fewer years of formal education consistently had greater declines in cognitive function, independently of age, birthplace, language of interview, occupation, and income. These prospective findings suggest that low educational attainment or a correlate predicts cognitive decline. It is not clear, however, whether this relation represents a direct effect of education on future cognition, whether education might be related to occurrence of a disease leading to cognitive decline in older persons, or whether education might be a surrogate for some variable not included in the study.

Trends in the incidence and prevalence of Alzheimer’s disease, dementia, and cognitive impairment in the United States

Declines in heart disease and stroke mortality rates are conventionally attributed to reductions in cigarette smoking, recognition and treatment of hypertension and diabetes, effective medications to improve serum lipid levels and to reduce clot formation, and general lifestyle improvements. Recent evidence implicates these and other cerebrovascular factors in the development of a substantial proportion of dementia cases. Analyses were undertaken to determine whether corresponding declines in age‐specific prevalence and incidence rates for dementia and cognitive impairment have occurred in recent years. Data spanning 1 or 2 decades were examined from community‐based epidemiological studies in Minnesota, Illinois, and Indiana, and from the Health and Retirement Study, which is a national survey. Although some decline was observed in the Minnesota cohort, no statistically significant trends were apparent in the community studies. A significant reduction in cognitive impairment measured by neuropsychological testing was identified in the national survey. Cautious optimism appears justified.

Elder Self-neglect and Abuse and Mortality Risk in a Community-Dwelling Population

CONTEXT Both elder self-neglect and abuse have become increasingly prominent public health issues. The association of either elder self-neglect or abuse with mortality remains unclear. OBJECTIVE To examine the relationship of elder self-neglect or abuse reported to social services agencies with all-cause mortality among a community-dwelling elderly population. DESIGN, SETTING, AND PARTICIPANTS Prospective, population-based cohort study (conducted from 1993 to 2005) of residents living in a geographically defined community of 3 adjacent neighborhoods in Chicago, Illinois, who were participating in the Chicago Health and Aging Project (CHAP; a longitudinal, population-based, epidemiological study of residents aged > or = 65 years). A subset of these participants had suspected elder self-neglect or abuse reported to social services agencies. MAIN OUTCOME MEASURES Mortality ascertained during follow-up and by use of the National Death Index. Cox proportional hazard models were used to assess independent associations of self-neglect or elder abuse reporting with the risk of all-cause mortality using time-varying covariate analyses. RESULTS Of 9318 CHAP participants, 1544 participants were reported for elder self-neglect and 113 participants were reported for elder abuse from 1993 to 2005. All CHAP participants were followed up for a median of 6.9 years (interquartile range, 7.4 years), during which 4306 deaths occurred. In multivariable analyses, reported elder self-neglect was associated with a significantly increased risk of 1-year mortality (hazard ratio [HR], 5.82; 95% confidence interval [CI], 5.20-6.51). Mortality risk was lower but still elevated after 1 year (HR, 1.88; 95% CI, 1.67-2.14). Reported elder abuse also was associated with significantly increased risk of overall mortality (HR, 1.39; 95% CI, 1.07-1.84). Confirmed elder self-neglect or abuse also was associated with mortality. Increased mortality risks associated with either elder self-neglect or abuse were not restricted to those with the lowest levels of cognitive or physical function. CONCLUSION Both elder self-neglect and abuse reported to social services agencies were associated with increased risk of mortality.

National estimates of the prevalence of Alzheimer's disease in the United States*

Several methods of estimating prevalence of dementia are presented in this article. For both Brookmeyer and the Chicago Health and Aging project (CHAP), the estimates of prevalence are derived statistically, forward calculating from incidence and survival figures. The choice of incidence rates on which to build the estimates may be critical. Brookmeyer used incidence rates from several published studies, whereas the CHAP investigators applied the incidence rates observed in their own cohort. The Aging, Demographics, and Memory Study (ADAMS) and the East Boston Senior Health Project (EBSHP) were sample surveys designed to ascertain the prevalence of Alzheimers disease and dementia. ADAMS obtained direct estimates by relying on probability sampling nationwide. EBSHP relied on projection of localized prevalence estimates to the national population. The sampling techniques of ADAMS and EBSHP were rather similar, whereas their disease definitions were not. By contrast, EBSPH and CHAP have similar disease definitions internally, but use different calculation techniques, and yet arrive at similar prevalence estimates, which are considerably greater than those obtained by either Brookmeyer or ADAMS. Choice of disease definition may play the larger role in explaining differences in observed prevalence between these studies.

Educational attainment and cognitive decline in old age

Background: Level of education is a well-established risk factor for Alzheimer disease but its relation to cognitive decline, the principal clinical manifestation of the disease, is uncertain. Methods: More than 6,000 older residents of a community on the south side of Chicago were interviewed at approximately 3-year intervals for up to 14 years. The interview included administration of four brief tests of cognitive function from which a previously established composite measure of global cognition was derived. We estimated the associations of education with baseline level of cognition and rate of cognitive change in a series of mixed-effects models. Results: In an initial analysis, higher level of education was related to higher level of cognition at baseline, but there was no linear association between education and rate of change in cognitive function. In a subsequent analysis with terms to allow for nonlinearity in education and its relation to cognitive decline, rate of cognitive decline at average or high levels of education was slightly increased during earlier years of follow-up but slightly decreased in later years in comparison to low levels of education. Findings were similar among black and white participants. Cognitive performance improved with repeated test administration, but there was no evidence that retest effects were related to education or attenuated education’s association with cognitive change. Conclusions: The results suggest that education is robustly associated with level of cognitive function but not with rate of cognitive decline and that the former association primarily accounts for education’s correlation with risk of dementia in old age.

Identifying Adverse Events Caused by Medical Care: Degree of Physician Agreement in a Retrospective Chart Review

Retrospective case review has long been a main-stay of peer review. It supports scientific studies and medical audits as well as assessments of the appropriateness, effectiveness, and quality of health care provided by physicians, hospitals, or regions. As part of quality assurance, hospitals and clinics regularly use formal and informal case review. Insurers and managed care organizations rely on case review when making decisions about coverage. All forms of case review depend heavily on expert opinion. Case review also underlies current and proposed systems of compensating patients for injuries caused by medical care. Under the current litigation system, the patient must prove, with the support of expert medical opinion, that medical care contributed to the injury (causation) and fell below the standards of practice in the community (negligence). Under proposed no-fault alternatives to litigation, entitlement to compensation and liability for payment might also depend on an experts opinion as to whether the patients outcome was caused by medical care rather than by a preexisting disease or condition [1-4]. Critics have identified several problems with case review. First, experts cannot form a consensus about which outcomes are adverse. Second, medical technology changes rapidly and creates uncertainty about the appropriateness and effectiveness of practices. Third, administrative or transaction costs in making individualized determinations of causation might be high [5-8]. The American College of Physicians [9] and others [10] have called for further demonstration projects. Building on previous research on the reliability of clinical judgments, we used a large sample of physician reviews of medical records to estimate the degree of agreement on the cause of adverse patient outcomes. We also discuss the implications of the results for quality assurance, performance assessment, and proposals for no-fault patient compensation. Methods Cases were obtained from the Medical Practice Study, a project designed to estimate the rate of adverse events occurring among inpatients in a random sample of 31 429 medical records from 51 health care facilities in New York State. We defined an adverse event as an injury that 1) was caused at least in part by medical management and 2) required or prolonged hospitalization or led to disability after discharge. The injury could result from a providers action or inaction in either inpatient or outpatient settings or from a drug or medical device. The medical management did not have to be substandard or inappropriate; the injury could follow an unexpected complication. Adverse outcomes caused solely by underlying disease or by the intended consequences of treatment were not considered to be adverse events. For example, an injury to the recurrent laryngeal nerve during partial thyroidectomy (an unplanned and unintended but recognized complication) would be considered an adverse event, but the intentional destruction of the same nerve in a radical thyroid resection for cancer would not. A broken experimental balloon that led to an embolus and stroke during cardiac catheterization would, as a complication of treatment, also be an adverse event, especially if the patients risk was unknown. This result would apply even in a study approved by a Human Subjects Committee. Other aspects of the Medical Practice Study and the general methods have been widely reported [11-15]. The following methods are relevant to our report. Record Review Records were reviewed in two stages. In stage 1 (which is not the subject of this report), nurses and medical records administrators used a single review per case to screen the entire sample of records for the presence of 1 or more of 18 explicit criteria (Figure 2). These criteria were based primarily on previous research [16] and were revised by the physician investigators of the Medical Practice Study. Although explicit, the criteria were broad and open to interpretation. The nurses and records administrators received an extensive manual, which contained detailed examples of the criteria, and 2 hours of focused classroom training from team leaders chosen for this project. To increase the efficiency and accuracy of screening, the nurses and records administrators used preprinted forms generated by the project management team. Nurses were instructed to refer any questionable cases for stage 2 review. Questions of a more general nature were referred to supervisors and then to the project office for consistent responses. The estimated negative predictive value of the screening was 99.5% [17]. Figure 2. Screening Criteria Implemented at Stage 1 Review by Nurses and Medical Records Administrators. Judgments on adverse events by pairs of physician-reviewers and rate of agreement on occurrence of adverse events compared with extreme disagreement. If a = cases of extreme disagreement (one reviewer scored the outcome as 0 [no possible adverse event] and the other scored the case as 4, 5, or 6) and b = cases for which both reviewers found adverse events (both scored the case as 4, 5, or 6), then the reported rate of agreement = a/(a + b). Bars represent exact binomial 95% CIs. Numbers in parentheses are the population-weighted estimates of the number of cases in New York State in 1984 that are represented by the sampled cases reported in this figure. In stage 2, each record that had or may have had at least one criterion present was further analyzed by two physicians who worked independently. Physicians were recruited primarily from New York State through a network of personal contacts of the study investigators. The physicians could not review records at the hospitals in which they practiced. Most were board certified in surgery (23%) or internal medicine (68%); the remaining were certified in obstetrics and gynecology, family practice, pediatrics, urology, or emergency medicine. Eighty-five percent were male. Most physicians were in the early stage of their careers: Fifty-five percent had received board certification within the 10 years before the study began. All physicians had telephone access to a panel of experts. A separate manual and a structured abstraction form guided the stage 2 review. As described previously [17], both were revised repeatedly after extensive pilot testing. This 65-page manual included explicit instructions on several types of adverse events. According to the manual, for example, all surgical wound infections were almost invariably adverse events, as were all falls and all drug reactions that prolonged hospitalization or caused disability. A 14-page abstraction form first asked the physician reviewer to assess whether an adverse event might have occurred. If the physician found no possible adverse event, the review was stopped and the case received a score of 0. If an adverse event might have occurred, the reviewer considered a list of factors on the cause of the injury and rated his or her confidence about the occurrence of an adverse event on an interval scale of 1 to 6 (Figure 1). For a confidence score of 2 (slight to modest evidence of an adverse event) or greater, the reviewer indicated the type of event (fall, drug reaction, wound infection, error of omission, or failure to diagnose), the number of additional days of hospitalization (if applicable), and the degree of disability over and above the underlying disease. Finally, the reviewers considered whether the error amounted to negligence. Within this structure, however, the physician could be discreet in judging the cause of the injury, hospitalization, or disability (a structured implicit review). All physician reviewers identified themselves by number, with the understanding that their confidential opinions would not be used for quality assurance, peer review, or litigation. Copies of the abstraction booklet are available from the authors. Figure 1. Our report focuses on the two independent expert opinions obtained during stage 2 review as to whether an adverse outcome identified during stage 1 had been caused at least in part by medical management. Results of each assessment of causation were linked to the patients computerized discharge data summary to identify the patients age, diagnosis, and discharge status. Statistical Analysis Agreement between Reviewers We calculated a rate of agreement between the two physician reviewers in each pair on adverse events using a statistic described by Grant [18] for assessing agreement on abnormal tracings from electronic fetal monitoring. In our application, the numerator of this statistic was the number of cases in which both reviewers assessed their confidence in an adverse event as more likely than not or greater. This assessment corresponded to a score of 4, 5, or 6. The denominator was the sum of the numerator and the number of cases of extreme disagreement, for which one reviewer scored the case as 4, 5, or 6 and the other physician found no possible adverse event (a score of 0). The statistic therefore compared the number of cases with agreed-upon adverse events with the number of clear disagreements. This statistic does not include cases for which both physicians agreed that no adverse event had occurred. It recognizes that agreement about whether a patients condition is normal (no adverse event) is usually greater than agreement about whether a patient has disease or an abnormal condition [19-22]. The statistic is also not affected by the number of clearly normal cases in the samples of cases for review. In our study, the number of cases clearly without adverse events at stage 2 was influenced by the coarseness of the previous screening process. The stage 1 reviewers were cautioned to avoid false-negative determinations if they were in doubt, so that adverse events would not be overlooked. This statistic also facilitated comparisons of rates of agreement across subsets of such adverse events as drug reactions, which are

Contribution of Alzheimer disease to mortality in the United States

Objective: To assess the burden of mortality attributable to Alzheimer disease (AD) dementia in the United States. Methods: Data came from 2,566 persons aged 65 years and older (mean 78.1 years) without dementia at baseline from 2 cohort studies of aging with identical annual diagnostic assessments of dementia. Because both studies require organ donation, ascertainment of mortality was complete and dates of death accurate. Mortality hazard ratios (HRs) after incident AD dementia were estimated per 10-year age strata from proportional hazards models. Population attributable risk percentage was derived to estimate excess mortality after a diagnosis of AD dementia. The number of excess deaths attributable to AD dementia in the United States was then estimated. Results: Over an average of 8 years, 559 participants (21.8%) without dementia at baseline developed AD dementia and 1,090 (42.4%) died. Median time from AD dementia diagnosis to death was 3.8 years. The mortality HR for AD dementia was 4.30 (confidence interval = 3.33, 5.58) for ages 75–84 years and 2.77 (confidence interval = 2.37, 3.23) for ages 85 years and older (too few deaths after AD dementia in ages 65–74 were available to estimate HR). Population attributable risk percentage was 37.0% for ages 75–84 and 35.8% for ages 85 and older. An estimated 503,400 deaths in Americans aged 75 years and older were attributable to AD dementia in 2010. Conclusions: A larger number of deaths are attributable to AD dementia in the United States each year than the number (<84,000 in 2010) reported on death certificates.