Case-finding Methods Research Articles

Incidence of parkinsonism and Parkinson disease in a general population: the Rotterdam Study.

To investigate the incidence of parkinsonism and Parkinson disease (PD) in the general population using in-person screening along with clinical data. In the Rotterdam study, a prospective population-based cohort study of people aged > or =55 years, the authors assessed age- and sex-specific incidence rates of parkinsonism and PD among 6,839 participants who were free of parkinsonism at baseline. Case finding involved in-person screening at baseline and two follow-up visits, and additional information was obtained through continuous monitoring of the cohort by computer linkage to general practitioners' and pharmacy records. After a mean follow-up period of 5.8 years, 132 subjects with incident parkinsonism were identified, of whom 67 (51%) had PD. The incidence of parkinsonism and PD increased with age, with incidence rates for PD increasing from 0.3 per 1000 person-years in subjects aged 55 to 65 years, to 4.4 per 1000 person-years for those aged > or =85 years. The overall age-adjusted incidence rate of any parkinsonism was not different in men and women, but men seem to have a higher risk for PD (male-to-female ratio, 1.54; 95% CI, 0.95 to 2.51). Incidence rates for parkinsonism and Parkinson disease were higher than those reported by most previous studies, possibly because of the authors' intensive case-finding methods involving in-person screening.

Development and evaluation of a patient self-report case-finding method for rheumatoid arthritis

Objective To describe the development and evaluation of a patient self-report case-finding method for rheumatoid arthritis (RA) not dependent on direct contact with the treating physicians. Methods The American College of Rheumatology criteria for RA diagnosis were adapted for patient self-report using a questionnaire, and alternative scoring algorithms were evaluated to balance case-finding sensitivity and specificity. Positive rheumatoid factor tests were used to identify 1053 individuals in 2 large healthcare organizations; 440 agreed to receive study materials. Case-finding results were validated by medical record review (MRR) for a random sample of 90 patients. Three scoring algorithms were compared with MRR for likelihood of RA diagnosis. Cases not classifiable by algorithm were flagged and reviewed by 2 expert physicians for likelihood of RA diagnosis. Results Pilot testing demonstrated that patients comprehended the questionnaire and were willing to answer the questions. Completed questionnaires were returned by 265 (60%) of the 440 patients contacted. Following expert physician review of 16 flagged cases in the 90-patient MRR subsample, the most accurate scoring algorithm demonstrated 80% sensitivity, 67% specificity, 74% accuracy, and 77% positive predictive value for detecting early RA. Conclusion The case-finding method represents a promising tool for identifying RA patients, with potential application in research and quality-assurance activities. Relevance This case-finding method should be useful in research and quality-assurance efforts requiring identification of RA patients treated by all types of providers in healthcare organizations in which centralized laboratory data are available.

Epidemiology of primary biliary cirrhosis in Victoria, Australia: High prevalence in migrant populations

Background & Aims: The prevalence of primary biliary cirrhosis (PBC) reported in different countries varies widely, indicating that genetic or environmental factors may be important in the etiology of the disease. The aim of this study was to examine this issue further by determining the overall prevalence of PBC in one state in Australia and to examine the prevalence among different migrant groups within this population. Methods: Thorough case-finding methods were used to identify all cases of PBC in Victoria, Australia. Age-adjusted prevalence rates among different migrant groups were examined. Results: A total of 249 cases were identified, giving a prevalence of 51 cases per million. This is significantly higher than the rate documented in a 1991 Victorian study. Prevalence in the 3 largest migrant groups was greater than that of Victoria as a whole (141, 200, and 208 cases per million in British, Italian, and Greek migrants, respectively). In women older than 40 years, previous studies have documented a prevalence of 940 cases per million in women in the United Kingdom; however, the prevalence was 344 cases per million in British-born immigrants to Victoria and 160 cases per million in Australian-born women. Conclusions: The current prevalence of PBC in Victoria is higher than previously reported, but the age-adjusted prevalence in those born in Victoria remains significantly lower than in the United Kingdom and is less than in migrant communities. These findings suggest that Victorians may be relatively protected from developing the disease and add further weight to the suggestion that environmental factors may play a role in the etiology of PBC.

A Comparison of Three Dementia Screening Instruments Administered by Telephone in China

Implementation of valid and efficient case-finding methods to screen for cognitive impairment is important for identifying people during the earliest stages of dementia. The Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), Information-Memory-Concentration Test (IMCT), and Blessed-Roth Dementia Scale (BRDS) are assessment tools commonly used in China. This study investigated the usefulness of administering these scales by telephone. Subjects ( N= 132: 74 females, 58 males) from Xuanwu Hospital, Capital University of Medical Sciences in Beijing, China were recruited for participation in this study; 132 collateral informants who accompanied the subjects to their appointments provided IQCODE and BRDS data. Senior neurologists using Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria (American Psychiatric Publishing, 2000), patient history, physical examination, neuropsychological tests, neuroradiology, and laboratory tests made the dementia diagnoses. Blinded personnel administered the IQCODE, IMCT, and BRDS by telephone and face-to-face in the clinic in counter-balanced administration order. Independent subsamples of 20 subjects were selected for assessment of test-retest and inter-rater reliabilities of the telephone assessments. Correlations between the face-to-face and telephone administrations of the scales were good, ranging from .80 to .97. The administration order of assessment methods did not affect the results. Inter-rater and test-retest reliabilities were satisfactory. The sensitivity and specificity of each scale exceeded 80 percent, demonstrating scale validity and clinical utility. The results support reliable and valid administration of these dementia assessments in person or over the telephone. The appropriate selection of assessment instruments is dependent upon the characteristics of the patient population and the intended use of the results. Use of telephone assessments may provide a valid and efficient method to screen elderly people for early detection of dementia symptoms and to monitor the effectiveness of treatment.

Somatization disorder in young adult population

Somatization is a widespread problem in health care. We estimated the occurrence of Somatization Disorder (SD) using three different case-finding methods in a general population cohort. The sample consists of 1,598 subjects born in 1966. The case-finding methods according to the DSM-III-R criteria for SD were: 1) Finnish Hospital Discharge Register (FHDR) data, 2) analysis of the patient records in public outpatient care 1982-1997, and 3) Structured Clinical Interview for DSM-III-R (SCID) for 321 selected cases. The prevalence of SD was 1.1% ( N = 18), giving a female-to-male ratio of 5:1. All cases were found among the public outpatient care records. No cases appeared in the FHDR or were recognized in the psychiatric interview. The lifetime prevalence of SD was comparable with previous western population studies. Methodologically, information from outpatient records may be more sensitive in detecting SD than hospital diagnosis or even psychiatric interview. Clinically we stress the importance of recognizing these cases by liaison psychiatrists especially because SD has been recognized as being difficult to treat among somatic and primary health service providers and because some promising treatment alternatives such as cognitive-behavioral therapy and antidepressants have emerged for SD patients.

Strongly Positive Tissue Transglutaminase Antibody Assays without Celiac Disease

Celiac disease is a small bowel disorder characterized by flattened villi and crypt hyperplasia, often with malabsorption. Improvement occurs with a gluten-free diet. Sensitive and specific assays (eg, immunoglobulin A antibodies to tissue transglutaminase [tTG]) that can be quantified appear to be valuable tools for population screening studies. In addition, their use is expanding widely in the clinical practice arena, being employed as a method of case finding. In this evaluation, clinical use of a commercially available test kit was explored. Of 1330 samples submitted to our hospital laboratory by physicians in British Columbia, Alberta and the Yukon Territory (from 1999 to 2003, inclusive), 96 patients (7%) had increased values (normal range greater than 20 units) and markedly increased levels greater than 100 units were detected in 36 patients (3%). Of these, 14 patients (almost 40%) were referred to gastroenterologists in our hospital and all 14 had small intestinal biopsies. Of these, three patients (more than 20%) did not have celiac disease. Two had normal small bowel biopsies and one had unclassified sprue or 'sprue-like' intestinal disease that failed to respond to a gluten-free diet. The other 11 had biopsy-defined celiac disease. While the tTG assay may be a useful predictor of celiac disease, small intestinal biopsy is still required to confirm the diagnosis. In clinical practice, even strongly positive tTG results are not specific in individual patients, do not necessarily correlate with the degree of severity of biopsy change and, as a result, are also unlikely to be useful for monitoring diet compliance.

Retrospective drug utilization review: incidence of clinically relevant potential drug-drug interactions in a large ambulatory population.

To determine the incidence of clinically relevant potential drug-drug interactions (DDIs) in a large population of ambulatory patients utilizing a computerized, retrospective drug utilization review (DUR) program followed by clinical pharmacist audit. The drug claims database included approximately 2.9 million patients with more than 30 million prescriptions dispensed in the 12-month period from September 2001 through August 2002. Cases were identified by a computerized, retrospective DUR program with embedded triggers to detect 69 prespecified potentially serious DDIs, with "serious" defined as an interaction that would likely require a change in therapy or use of additional clinical or laboratory monitoring. Two types of automated, computerized assessments were conducted: the first simply detected coprescribed drug pairs, and the second assessment used more sophisticated filters to reduce false positive alerts for coprescribed drug pairs. Clinical pharmacist audit then determined the final incidence of clinically relevant warnings; in this audit, coprescribed drug pairs were defined as clinically relevant if they could cause potentially serious DDIs. Eighteen drug pairs had insufficient cases for inclusion, leaving 51 drug pairs for evaluation. A total of 244,703 cases of potential DDIs were identified (0.8% of total prescription claims) by simple automated screens. More sophisticated DDI filters reduced the 244,703 potential DDIs by 70.8%, to a total of 65,544 pairs (0.2% of total prescription claims). Clinical pharmacist review reduced the number of potential DDIs by an additional 80.6%, to 12,722 drug pairs (0.04% of total prescription claims) deemed clinically relevant. The combination of sophisticated DDI filters and clinical pharmacist review reduced the incidence of potentially serious DDIs by 94.3%. The incidence of potentially serious DDIs is relatively low (less than 1%) among ambulatory patients; however, the incidence depends on the method of case finding. Retrospective DUR programs, especially those with additional automated filters or that utilize additional pharmacist review, appear to be important screening tools in determining true rates of coprescribed drug pairs that can lead to potentially serious DDIs.

Familiarity breeds neglect? Unanticipated benefits of discontinuous primary care.

Continuity of medical care is generally considered to be beneficial to patients. The aim of this study was to investigate the possibility that familiarity with patients may sometimes discourage case finding. Extensive qualitative interviews were carried out with a sample of Australian adults with type 2 diabetes, focusing in particular on their experience of diagnosis. Interviews were conducted with 119 participants, 75% of whom supplied sufficient information to enable the coding of whether diagnosis occurred under circumstances of discontinuity. Half of all participants (two-thirds of the coded subsample) had a diagnosis that could be categorized as resulting from discontinuous primary care: hospital admission, change of doctor, patient initiative and/or diabetic emergency. The same circumstances that enhance the management of chronic disease can at times hinder its diagnosis. Primary care service providers may need to instigate more active methods of case finding in order to avoid this paradoxical effect of familiarity with the patient.

Incidence and short-term prognosis of status epilepticus in adults in Bologna, Italy.

To determine the incidence and the 30-day case fatality of status epilepticus (SE) in the adult resident population of the city of Bologna, Italy. Over a 1-year period (March 1, 1999 to February 29, 2000), all patients older than 20 years with SE were included. The case-finding method was based on (a) a prospective surveillance of all public general hospitals in the city by neurologic units, and (b) a review of all discharge codes concerning epilepsy. The crude and standardized annual incidence rate of SE was 13.1 per 100,000 [95% confidence interval (CI), 9.5-17.5] and 10.7 (95% CI, 7.5-13.8). It was higher in the elderly (older than 60 years) than in young adults (26.2 vs. 5.2) and in women than in men (14.9 vs. 11.0). Acute symptomatic SE accounted for 48%, and a cerebrovascular pathology was the most frequently associated etiologic condition (41%). A history of seizures was reported in 39% of patients. The 30-day case fatality was 39% (33% excluding postanoxic patients). This study reports the first data on the epidemiology of SE in Italy. The incidence rate found in the population of Bologna is in the same range as that of the other European countries. The 30-day case fatality is higher than all the other population studies (both European and American), despite the broadly similar clinical features of patients. Indirect evidence suggests that some inaccurate patient management could have negatively influenced the outcome of SE.

Strengthening the BTWC: The role of the Biological and Toxin Weapons Convention in combating natural and deliberate disease outbreaks

Strengthening the BTWC: The role of the Biological and Toxin Weapons Convention in combating natural and deliberate disease outbreaks

What is the limit to case detection under the DOTS strategy for tuberculosis control?

In year 2000, the WHO DOTS strategy for tuberculosis (TB) control had been adopted by 148 out of 212 countries, but only 27% of all estimated sputum smear-positive patients were notified under DOTS in that year. Here we investigate the way in which gains in case detection under DOTS were made up until 2000 in an attempt to anticipate future progress towards the global target of 70% case detection. The analysis draws on annual reports of DOTS geographical coverage and case notifications, and focuses on the 22 high-burden countries (HBCs) that account for about 80% of new TB cases arising globally each year. Our principal observation is that, as TB programmes in the 22 HBCs have expanded geographically, the fraction of the estimated number of sputum smear-positive cases detected within designated DOTS areas has remained constant at 40–50% although there are significant differences between countries. This fraction is about the same as the percentage of all smear-positive cases notified annually to WHO via public health systems worldwide. The implication is that, unless the DOTS strategy can reach beyond traditional public health reporting systems, or unless these systems can be improved, case detection will not rise much above 40% in the 22 HBCs, or in the world as a whole, even when the geographical coverage of DOTS is nominally 100%. We estimate that, under full DOTS coverage, three-quarters of the undetected smear-positive cases will be living in India, China, Indonesia, Nigeria, Bangladesh and Pakistan. But case detection could also remain low in countries with smaller populations: in year 2000, over half of all smear-positive TB cases were living in 49 countries that detected less than 40% of cases within DOTS areas. Substantial efforts are therefore needed (a) to develop new case finding and management methods to bridge the gap between current and target case detection, and (b) to improve the accuracy of national estimates of TB incidence, above all by reinforcing and expanding routine surveillance.

Endocrinological disorders and celiac disease.

Celiac disease is a permanent intolerance to dietary gluten. Its well known features are abdominal symptoms, malabsorption of nutrients, and small-bowel mucosal inflammation with villous atrophy, which recover on a gluten-free diet. Diagnosis is challenging in that patients often suffer from subtle, if any, symptoms. The risk of clinically silent celiac disease is increased in various autoimmune conditions. The endocrinologist, especially, should maintain high suspicion and alertness to celiac disease, which is to be found in 2-5% of patients with insulin-dependent diabetes mellitus or autoimmune thyroid disease. Patients with multiple endocrine disorders, Addison's disease, alopecia, or hypophysitis may also have concomitant celiac disease. Similar heredity and proneness to autoimmune conditions are considered to be explanations for these associations. A gluten-free diet is essential to prevent celiac complications such as anemia, osteoporosis, and infertility. The diet may also be beneficial in the treatment of the underlying endocrinological disease; prolonged gluten exposure may even contribute to the development of autoimmune diseases. The diagnosis of celiac disease requires endoscopic biopsy, but serological screening with antiendomysial and antitissue transglutaminase antibody assays is an easy method for preliminary case finding. Celiac disease will be increasingly detected provided the close association with autoimmune endocrinological diseases is recognized.

An epidemiological survey of hemiplegic migraine.

The objective of the present study was to use systematic nation-wide case-finding methods to establish the prevalence and sex ratio of hemiplegic migraine (HM) in the entire Danish population of 5.2 million inhabitants. Affected patients were identified from three different recruitment sources: the National Patient Register, case records from private practising neurologists and advertisements. Based on the observed number of affected patients from each case-finding method, it was attempted to estimate the total number of affected patients by means of the statistical method known as capture-recapture. Two hundred and ninety-one affected patients were identified; 147 were familial HM from 44 different families, 105 were sporadic HM and 39 were unclassifiable HM. The HM sex ratio (M:F) was 1:3. Based on the identified number of affected patients the prevalence of HM at the end of 1999 was estimated to be 0.01% in Denmark, where the familial and sporadic form were equally frequent.

Sixteen years' surveillance of surgical sites in an Irish acute-care hospital.

To report a program of continuous surveillance of surgical-site infections (SSIs) using basic surveillance methods. Analysis of routine prospective surveillance data. Two hospitals in Ireland (300 and 350 beds) that merged and moved to a new 650-bed hospital in 1987. 59,335 surgical sites of postoperative patients. Surgical sites were surveyed by one infection control nurse and SSI rates were produced for selected operations and surgical services. The program was conducted in general accordance with the 1999 HICPAC guidelines, but differed in surveillance strategy. Operations were limited to two to three risk classifications, assigned by the infection control nurse. The overall SSI rate was 4.5%, with 2.4% in clean surgery. Apart from increases in the 3rd, 4th, 13th, and 14th years, rates remained relatively stable during the 16 years. Few significant decreases in SSI rates in surgical services or specific operations were shown, apart from the following: vascular surgery, 8.1% to 5% between the first 8 years and the last 8 years; general surgery services, 9% to 5%, and gynecology, 15.8% to 1.7%, both in the first year compared with in subsequent years; and gastric operations, 21% to 4.3% between the first year and the second year. Organ/space infection was identified in 0.5% of 17,804 operations, including 0.4% meningitis after neurosurgical procedures, 3% graft infections after vascular bypass operations, and 0.2% intra-abdominal infections after abdominal surgery. With the use of basic principles of surveillance and modest resources, procedure-specific SSI rates were produced, with little significant change during the 16 years. Despite limitations in case-finding, risk stratification, feedback, and surveillance methods, the overall SSI rates were comparable with other published data.

Prevalence of autism in a United States population: the Brick Township, New Jersey, investigation.

This study determined the prevalence of autism for a defined community, Brick Township, New Jersey, using current diagnostic and epidemiologic methods. The target population was children who were 3 to 10 years of age in 1998, who were residents of Brick Township at any point during that year, and who had an autism spectrum disorder. Autism spectrum disorder was defined as autistic disorder, pervasive developmental disorder-not otherwise specified (PDD-NOS), and Asperger disorder. The study used 4 sources for active case finding: special education records, records from local clinicians providing diagnosis or treatment for developmental or behavioral disabilities, lists of children from community parent groups, and families who volunteered for participation in the study in response to media attention. The autism diagnosis was verified (or ruled out) for 71% of the children through clinical assessment. The assessment included medical and developmental history, physical and neurologic evaluation, assessment of intellectual and behavioral functioning, and administration of the Autism Diagnostic Observation Schedule-Generic. The prevalence of all autism spectrum disorders combined was 6.7 cases per 1000 children. The prevalence for children whose condition met full diagnostic criteria for autistic disorder was 4.0 cases per 1000 children, and the prevalence for PDD-NOS and Asperger disorder was 2.7 cases per 1000 children. Characteristics of children with autism in this study were similar to those in previous studies of autism. The prevalence of autism in Brick Township seems to be higher than that in other studies, particularly studies conducted in the United States, but within the range of a few recent studies in smaller populations that used more thorough case-finding methods.

Multicenter surveillance study for nosocomial infections in major hospitals in Korea

Background: The goals of a surveillance for nosocomial infections (NIs) are to observe the magnitude and characteristics of NIs and to plan and evaluate policies and guidelines of infection control. This study was designed to determine the rate and distribution of NIs and their causative pathogens in Korean hospitals. Methods: Prospective surveillance was performed at 15 acute care hospitals with more than 500 beds during a 3-month period from June to August 1996. The case-finding methods were laboratory-based surveillance for patients in the general wards and a direct review of medical charts done regularly for all the patients in the intensive care units. Results: A total of 3162 NIs were found among 85,547 discharged patients, with an overall nosocomial infection rate of 3.70 per 100 patients discharged. Urinary tract infections constituted 30.3% of all NIs. Other infections were pneumonias, 17.2%, surgical site infections, 15.5%, and primary bloodstream infections, 14.5%. The infection rate was the highest in neurosurgery (14.21), followed by neurology (8.62) and ontology services (6.70). The infection rate in intensive care units was higher than it was in the general wards (10.74 vs 2.57, P =.001). The commonly isolated organisms were Staphylococcus aureus (17.2%), Pseudomonas aeruginosa (13.8%), and Escherichia coli (12.3%). Conclusions: This first multicenter surveillance study provided extensive information on the current status and trends of NIs in major hospitals in Korea. The results may contribute to the evaluation of infection control programs and the development of effective strategies in these hospitals. (AJIC Am J Infect Control 2000;28:454-8)

Incidence of brain tumours in two English counties: a population based study

OBJECTIVETo define the incidence of brain tumours in Devon and Cornwall and to discover which case finding methods are the most fruitful. To examine what happens to patients after the...

Lower extremity amputations in diabetic and non diabetic individuals — a case finding method based on hospital discharge diagnosis

Lower extremity amputations in diabetic and non diabetic individuals — a case finding method based on hospital discharge diagnosis

Use of ICD-9-CM coding as a case-finding method for sternal wound infections after CABG procedures

Surgical site infection of the sternal wound in patients who have undergone coronary artery bypass grafting (CABG) results in high morbidity, mortality, and significantly increased costs. 1 Borger MA Rao V Weisel RD Ivanov J Cohen G Scully HE et al. Deep sternal wound infection: risk factors and outcomes. Ann Thorac Surg. 1998; 65: 1050-1056 Abstract Full Text Full Text PDF PubMed Scopus (279) Google Scholar , 2 Boyce JM Potter-Bynoe G Dziobek L. Hospital reimbursement patterns among patients with surgical wound infections following open heart surgery. Infect Control Hosp Epidemiol. 1990; 11: 89-93 Crossref PubMed Google Scholar , 3 Loop FD Lytle BW Cosgrove DM Mahfood S McHenry MC Goormastic M Stewart RW Golding LA Taylor PC.J. Maxwell Chamberlain memorial paper. Sternal wound complications after isolated coronary artery bypass grafting: early and late mortality, morbidity, and cost of care. Ann Thorac Surg. 1990; 49 (discussion 86-7): 179-186 Abstract Full Text PDF PubMed Scopus (611) Google Scholar , 4 Stahle E Tammelin A Bergstrom R Hambreus A Nystrom SO Hansson HE. Sternal wound complications—incidence, microbiology and risk factors. Eur J Cardiothorac Surg. 1997; 11: 1146-1153 Crossref PubMed Scopus (204) Google Scholar , 5 Taylor GJ Mikell FL Moses HW Dove JT Katholi RE Malik SA et al. Determinants of hospital charges for coronary artery bypass surgery: the economic consequences of postoperative complications. Am J Cardiol. 1990; 65: 309-313 Abstract Full Text PDF PubMed Scopus (177) Google Scholar Surveillance for these infections is recognized as an important component of quality improvement programs and infection prevention. 2 Boyce JM Potter-Bynoe G Dziobek L. Hospital reimbursement patterns among patients with surgical wound infections following open heart surgery. Infect Control Hosp Epidemiol. 1990; 11: 89-93 Crossref PubMed Google Scholar , 3 Loop FD Lytle BW Cosgrove DM Mahfood S McHenry MC Goormastic M Stewart RW Golding LA Taylor PC.J. Maxwell Chamberlain memorial paper. Sternal wound complications after isolated coronary artery bypass grafting: early and late mortality, morbidity, and cost of care. Ann Thorac Surg. 1990; 49 (discussion 86-7): 179-186 Abstract Full Text PDF PubMed Scopus (611) Google Scholar , 5 Taylor GJ Mikell FL Moses HW Dove JT Katholi RE Malik SA et al. Determinants of hospital charges for coronary artery bypass surgery: the economic consequences of postoperative complications. Am J Cardiol. 1990; 65: 309-313 Abstract Full Text PDF PubMed Scopus (177) Google Scholar , 6 Mangram AJ Horan TC Pearson ML Silver LC Jarvis WR. Guideline for prevention of surgical site infection, 1999. Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. Am J Infect Control. 1999; 27 (quiz 3-4; discussion 96): 97-132 Abstract Full Text Full Text PDF PubMed Google Scholar However, surveillance for surgical site infections (SSI) is labor intensive, requiring multiple case-finding methods and chart reviews. We report our evaluation of ICD-9-CM coding for sternal wound infections performed by medical record abstractors on hospital discharge as an indirect case-finding method.

The incidence and lifetime prevalence of neurological disorders in a prospective community-based study in the UK.

Over an 18-month period, all incident cases of neurological disorders were ascertained prospectively in an unselected urban population based in 13 general practices in the London area by a General Practice Linkage Scheme with the National Hospital for Neurology and Neurosurgery. In three of these practices, the lifetime prevalence of neurological disorders was also assessed. A population of 100 230 patients registered with participating general practices was followed prospectively for the onset of neurological disorders. Multiple methods of case finding were used to maintain accuracy. The age- and sex-adjusted incidence rates of neurological disorders were calculated. The lifetime prevalence of neurological disorders was surveyed in 27 658 of the patients. The age- and sex-adjusted incidence rates were calculated for major neurological conditions. [These are expressed as rates per 100 000 persons per annum, with 95% confidence intervals (CI) in parentheses]. The commonest of these were first cerebrovascular events, 205 (CI: 183, 230); shingles, 140 (CI: 104, 184); diabetic polyneuropathy, 54 (CI: 33, 83); compressive neuropathies, 49 (CI: 39, 61); epilepsy, 46 (CI: 36, 60); Parkinson's disease, 19 (CI: 12, 27); peripheral neuropathies, 15 (CI: 9, 23); CNS infections, 12 (CI: 5, 13); post-herpetic neuralgia, 11 (CI: 6, 17); and major neurological injuries, 10 (CI: 4, 11). Lifetime prevalence rates are also reported (expressed as rate per 1000 persons with 95% CI). The most prevalent conditions were: completed stroke, 9 (CI: 8, 11); transient ischaemic attacks, 5 (CI: 4, 6); active epilepsy, 4 (CI: 4, 5); congenital neurological deficit, 3 (CI: 3, 4); Parkinson's disease, 2 (CI: 1, 3); multiple sclerosis, 2 (CI: 2, 3); diabetic polyneuropathy, 2 (CI: 1, 3); compressive mononeuropathies, 2 (CI: 2, 3); and sub-arachnoid haemorrhage, 1 (CI: 0.8, 2). Overall, the onset of 625 neurological disorders was observed per 100 000 population annually. Six percent of the population had at some time had a neurological disorder. This is the first study of the incidence and lifetime prevalence of neurological disorders in recent times; we found that these disorders give rise to significant morbidity in the community.