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Biomedical subjects

Robert L Davis

Publications and source records attributed to Robert L Davis.

At least 19 recordsLinked to original sources
PubMed2007

Laboratory monitoring of potassium and creatinine in ambulatory patients receiving angiotensin converting enzyme inhibitors and angiotensin receptor blockers.

PURPOSE: Serum potassium and creatinine monitoring is recommended for patients prescribed angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB). Much has been written about hyperkalemia associated with these drugs; little is known about laboratory monitoring patterns. The purpose of this retrospective cohort study was to assess creatinine and potassium monitoring and characteristics associated with monitoring among patients dispensed ACEi or ARB. METHODS: This study was conducted in 10 United States health maintenance organizations. Study patients (n = 52 906) were aged 18 or older with dispensings of ACEi or ARB for at least 1 year. Serum potassium and creatinine monitoring were assessed from administrative data and medical records. RESULTS: More than two-thirds (68.4%) of patients received laboratory monitoring. Likelihood of monitoring increased with age (adjusted odds ratio [OR] 2.10; 95% confidence interval [95%CI] 1.93, 2.28 [individuals >or= 80 compared to <50 years]), >9 outpatient visits (OR 1.46; 95%CI 1.39, 1.54), hospitalization (OR 1.15; 95%CI 1.06, 1.25), concomitant medications (potassium [OR 2.01; 95%CI 1.84, 2.20], diuretics [OR 1.54; 95%CI 1.47, 1.61], digoxin [OR 1.15; 95%CI 1.01, 1.30]), and comorbidities (diabetes [OR 1.68; 95%CI 1.61, 1.75], heart failure [OR 1.73; 95%CI 1.57, 1.90], chronic kidney disease [OR 2.95; 95%CI 2.48. 3.51]). CONCLUSIONS: Nearly one-third of patients dispensed ACEi or ARB did not undergo laboratory monitoring at least yearly. Though patients at increased risk of hyperkalemia were more likely to be monitored, many remained unmonitored.

Adult↗
PubMed2007

Hepatitis B vaccine and risk of autoimmune thyroid disease: a Vaccine Safety Datalink study.

PURPOSE: Hepatitis B vaccine has been postulated as a possible cause of autoimmune disorders, including autoimmune thyroid diseases (ATD). Cases of Graves' disease and Hashimoto's thyroiditis, following hepatitis B vaccine have been reported to the Vaccine Adverse Events Reporting System (VAERS). To test the hypothesis that hepatitis B vaccine increases the risk of ATD, we conducted a case-control study, within the Vaccine Safety Datalink project. METHODS: We identified potential cases of Graves' disease and Hashimoto's thyroiditis, among persons aged 18-69 years from administrative data recorded by three health maintenance organizations (HMOs) and verified cases by medical record review. Controls were frequency-matched to cases by birth year, sex, and study site. Vaccine information was collected from administrative records, chart review, and telephone interviews with study subjects. We enrolled 355 Graves' disease cases, 418 Hashimoto's thyroiditis cases, and 1102 controls. We assessed the association between ever-receipt of hepatitis B vaccine, as well as receipt of hepatitis B vaccine less than 1 year, 1-5 years and at least 5 years prior to the index date, and the risk of ATD. RESULTS: Ever-receipt of hepatitis B vaccine was not associated with risk of Graves' disease (odds ratio (OR), 0.90; 95% confidence interval (CI), 0.62-1.32) or Hashimoto's thyroiditis (OR, 1.23; 95%CI, 0.87-1.73). There was also no association between the time interval since receipt of hepatitis B vaccination and either outcome. CONCLUSIONS: We did not observe an increased risk of Graves' disease or Hashimoto's thyroiditis, following receipt of hepatitis B vaccine.

Adolescent↗
PubMed2006

Safety of trivalent inactivated influenza vaccine in children 6 to 23 months old.

CONTEXT: Beginning with the winter season of 2004-2005, influenza vaccination has been recommended for all children 6 to 23 months old in the United States. However, its safety in young children has not been adequately studied in large populations. OBJECTIVE: To screen for medically attended events in the clinic, emergency department, or hospital after administration of trivalent inactivated influenza vaccine in children 6 to 23 months old. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort using self-control analysis, with chart review of significant medically attended events at 8 managed care organizations in the United States that comprise the Vaccine Safety Datalink. Participants were all children in the Vaccine Safety Datalink cohort 6 to 23 months old who received trivalent inactivated influenza vaccine between January 1, 1991, and May 31, 2003 (45,356 children with 69,359 vaccinations). MAIN OUTCOME MEASURE: Any medically attended event significantly associated with trivalent inactivated influenza vaccine in risk windows 0 to 3 days, 1 to 14 days (primary analysis), 1 to 42 days, or 15 to 42 days after vaccination, compared with 2 control periods, one before vaccination and the second after the risk window. All individual ICD-9 codes as well as predefined aggregate codes were examined. RESULTS: Before chart review, only 1 diagnosis, gastritis/duodenitis, was more likely to occur in the 14 days after trivalent inactivated influenza vaccine (matched odds ratio [OR], 5.50; 95% confidence interval [CI], 1.22-24.81 for control period 1, and matched OR, 4.33; 95% CI, 1.23-15.21 for control period 2). Thirteen medically attended events were less likely to occur after trivalent inactivated influenza vaccine, including acute upper respiratory tract infection, asthma, bronchiolitis, and otitis media. After chart review, gastritis/duodenitis was not significantly associated with trivalent inactivated influenza vaccine (matched OR, 4.00; 95% CI, 0.85-18.84 for control period 1; matched OR, 3.34; 95% CI, 0.92-12.11 for control period 2). CONCLUSIONS: In the largest population-based study to date of the safety of trivalent inactivated influenza vaccine in young children, there were very few medically attended events, none of which were serious, significantly associated with the vaccine. This study provides additional evidence supporting the safety of universally immunizing all children 6 to 23 months old with influenza vaccine.

Cohort Studies↗
PubMed2006

FDA drug prescribing warnings: is the black box half empty or half full?

PURPOSE: Black box warnings (BBWs) are the Food and Drug Administration's (FDA) strongest labeling requirements for high-risk medicines. It is unknown how frequently physicians prescribe BBW drugs and whether they do so in compliance with the warnings. The purpose of the present study was to assess the frequency of use of BBW medications in ambulatory care and prescribing compliance with BBW recommendations. METHODS: This retrospective study used automated claims data of 929 958 enrollees in 10 geographically diverse health plans in the United States to estimate frequency of use in ambulatory care of 216 BBW drugs/drug groups between 1/1/99 and 31/6/01. We assessed dispensing compliance with the BBW requirements for selected drugs. RESULTS: During a 30-month period, more than 40% of enrollees received at least one medication that carried a BBW that could potentially apply to them. We found few instances of prescribing during pregnancy of BBW drugs absolutely contra-indicated in pregnancy. There was almost no co-prescribing of contra-indicated drugs with the two QT-interval-prolonging BBW drugs evaluated. Most non-compliance occurred with recommendations for baseline laboratory monitoring (49.6% of all therapy initiations that should have been accompanied by baseline laboratory monitoring were not). CONCLUSIONS: Many individuals receive drugs considered to carry the potential for serious risk. For some of these drugs, use is largely consistent with their BBW, while for others it is not. Since it will not be possible to avoid certain drug- associated risks, it will be important to develop effective methods to use BBWs and other methods to minimize risks.

Adolescent↗
PubMed2006

Use of prescription medications with a potential for fetal harm among pregnant women.

PURPOSE: To estimate the prevalence of use of prescription drugs with a potential for fetal harm among pregnant women in the United States. METHODS: A retrospective study was conducted using the automated databases of eight health maintenance organizations involved in the HMO Research Network Center for Education and Research on Therapeutics (CERT). Women who delivered an infant from January 1996 to December 2000 were identified. The frequency of use of prescription drugs with a potential for fetal harm was based upon the expert review of a clinical teratologist and the U.S. Food and Drug Administration (FDA) risk classification system, assuming a gestational duration of 270 days. RESULTS: Among the 114 165 women with no documentation of a diagnosis suggesting potential pre-term birth or dispensing of ovulation stimulants in the 270 days before delivery, 1305 (1.1%) received a teratogenic drug during the 270 days before delivery, based upon the expert review of a clinical teratologist. A larger proportion of women received U.S. FDA category D or X drugs (5.8%; N = 6600). However, the general patterns of use were similar, with higher use in early pregnancy compared to later trimesters. The proportion of women dispensed a teratogen during pregnancy was substantially higher among women who received a teratogen in the 90 days before pregnancy compared to women who did not (adjusted RR = 38.9, 95%CI, 33.5, 45.3). CONCLUSIONS: Our results suggest that further efforts directed at physicians to counsel women or at the women themselves about the potential risks of particular medications appear warranted.

Drug Prescriptions↗
PubMed2006

Factors that are associated with parental acceptance of human papillomavirus vaccines: a randomized intervention study of written information about HPV.

OBJECTIVES: Prophylactic vaccines against human papillomavirus (HPV) are expected to be available for public use by 2007 and likely will be targeted to preadolescent children. Parental acceptance of these vaccines will be critical for their success. The objectives of this study were (1) to determine the overall acceptance of HPV vaccines for preadolescent children by parents, (2) to evaluate the influence of written educational information about HPV on parental acceptability of HPV vaccines, and (3) to identify independent predictors associated with HPV vaccine acceptability by parents. METHODS: A randomized intervention study within a cross-sectional survey was conducted. Parental HPV vaccine acceptability was measured under 3 different hypothetical scenarios. A self-administered survey on the knowledge, attitudes, and beliefs about HPV and HPV vaccines was sent to 1600 parents of 8- to 12-year-old children. In addition to a baseline paragraph about HPV that was received by all study participants, a random half of the study participants received a detailed "HPV Information Sheet" outlining the epidemiology and potential clinical sequelae of HPV infection. Independent predictors of parental HPV vaccine acceptability were determined using multivariate linear regression models. RESULTS: Parents who received the HPV information sheet had higher mean scores on the HPV knowledge assessment tool than the control group. However, despite this apparent improvement in knowledge, there was not a statistically significant difference in HPV vaccine acceptability between the 2 groups. CONCLUSIONS: Providing parents with an HPV information sheet did seem to improve knowledge about HPV, but this increased knowledge had little effect on the acceptability of these vaccines by parents for their children. Instead, attitudes and life experiences seemed to be more important factors influencing HPV vaccine acceptability among parents.

Attitude to Health↗
PubMed2006

Compliance with the recommendations for 2 doses of trivalent inactivated influenza vaccine in children less than 9 years of age receiving influenza vaccine for the first time: a Vaccine Safety Datalink study.

OBJECTIVES: Children <9 years of age do not respond optimally to a first dose of trivalent inactivated influenza vaccine, and so 2 doses of trivalent inactivated influenza vaccine are recommended for children <9 years of age who are being vaccinated for the first time. We conducted a population-based retrospective cohort study to evaluate compliance with the 2-dose trivalent inactivated influenza vaccine recommendations. POPULATION AND SETTING: We evaluated 125,928 children 6 months through 8 years of age who were enrolled in health maintenance organizations in the United States participating in the Vaccine Safety Datalink project and who received their first dose of trivalent inactivated influenza vaccine in the 2001-2002, 2002-2003, or 2003-2004 influenza seasons. RESULTS: Compliance with the 2 dose recommendations varied by age group and influenza season. Among children 6 to 23 months of age, the proportion of first-vaccinated children who received a second vaccination was 44% in 2001-2002, 54% in 2002-2003, and 29% in 2003-2004. Among children 2 to 8 years of age, the corresponding proportions were 15%, 24%, and 12%, respectively. In all seasons, compliance with the second vaccination was highest in children first vaccinated by mid-November. CONCLUSIONS: The majority of children who received their first dose of trivalent inactivated influenza vaccine did not complete the 2-dose series. The recently expanded recommendation for universal vaccination of children 6 to 59 months of age and their household contacts will substantially increase the number of children targeted for a first influenza vaccination. Noncompliance with the 2-dose trivalent inactivated influenza vaccine series may be associated with suboptimal protection against infection, which may impact the magnitude of the direct and indirect benefits achieved by the vaccination program.

Child↗
PubMed2006

A public health approach to pharmacogenomics and gene-based diagnostic tests.

While the human genome project is likely to lead to fundamental changes in our understanding of disease causation and our ability to screen for disease predisposition and treatment responsiveness, the current healthcare system is not properly aligned to ensure the proper use of these advances. As the pace of genetic technology development increases and new pharmacogenetic drugs and gene-based diagnostic tests increasingly impact providers, patients, health plans, payers and employers, it will be crucial to develop an evidence-based framework by which to evaluate these new tests and treatments. In order to increase the level of evidence available and allow for informed decisions in the face of strong marketing and advocacy forces, the authors suggest the development of one (or more) large clinical networks with the purpose of systematically evaluating the clinical effectiveness of new genomic applications, including pharmaceuticals and gene-based diagnostic tests, in 'real world' settings.

Evidence-Based Medicine↗
PubMed2006

Monitoring of drugs with a narrow therapeutic range in ambulatory care.

OBJECTIVES: To describe the proportion of patients receiving drugs with a narrow therapeutic range who lacked serum drug concentration monitoring during a 1-year period of therapy and to identify patient characteristics associated with lack of monitoring. STUDY DESIGN: Retrospective cohort. METHODS: Ambulatory patients (n = 17,748) at 10 health maintenance organizations who were receiving ongoing continuous drug therapy with digoxin, carbamazepine, divalproex sodium, lithium carbonate, lithium citrate, phenobarbital sodium, phenytoin, phenytoin sodium, primidone, quinidine gluconate, quinidine sulfate, procainamide hydrochloride, theophylline, theophylline sodium glycinate, tacrolimus, or cyclosporine for at least 12 months between January 1, 1999, and June 30, 2001, were identified. Serum drug concentration monitoring was assessed from administrative data and from medical record data. RESULTS: Fifty percent or more of patients receiving digoxin, theophylline, procainamide, quinidine, or primidone were not monitored, and 25% to 50% of patients receiving divalproex, carbamazepine, phenobarbital, phenytoin, or tacrolimus were not monitored. Younger age was associated with lack of monitoring for patients prescribed digoxin (adjusted odds ratio, 1.86; 95% confidence interval, 1.39-2.48) and theophylline (adjusted odds ratio, 1.58; 95% confidence interval, 1.23-2.04), while older age was associated with lack of monitoring for patients prescribed carbamazepine (adjusted odds ratio, 0.59; 95% confidence interval, 0.44-0.80) and divalproex (adjusted odds ratio, 0.50; 95% confidence interval, 0.38-0.66). Patients with fewer outpatient visits were also less likely to be monitored (P < .001). CONCLUSIONS: A substantial proportion of ambulatory patients receiving drugs with narrow intervals between doses resulting in beneficial and adverse effects did not have serum drug concentration monitoring during 1 year of use. Clinical implications of this finding need to be evaluated.

Ambulatory Care↗
PubMed2005

Potential medication dosing errors in outpatient pediatrics.

OBJECTIVE: To determine the prevalence of potential dosing errors of medication dispensed to children for 22 common medications. STUDY DESIGN: Using automated pharmacy data from 3 health maintenance organizations (HMOs), we randomly selected up to 120 children with a new dispensing prescription for each drug of interest, giving 1933 study subjects. Errors were defined as potential overdoses or potential underdoses. Error rate in 2 HMOs that use paper prescriptions was compared with 1 HMO that uses an electronic prescription writer. RESULTS: Approximately 15% of children were dispensed a medication with a potential dosing error: 8% were potential overdoses and 7% were potential underdoses. Among children weighing <35 kg, only 67% of doses were dispensed within recommended dosing ranges, and more than 1% were dispensed at more than twice the recommended maximum dose. Analgesics were most likely to be potentially overdosed (15%), whereas antiepileptics were most likely potentially underdosed (20%). Potential error rates were not lower at the site with an electronic prescription writer. CONCLUSIONS: Potential medication dosing errors occur frequently in outpatient pediatrics. Studies on the clinical impact of these potential errors and effective error prevention strategies are needed.

Adolescent↗
PubMed2005

Active surveillance of vaccine safety: a system to detect early signs of adverse events.

BACKGROUND: There currently are no population-based systems in the United States to rapidly detect adverse events after newly introduced vaccines. To evaluate the feasibility of developing such systems, we used 5 years of data from 4 health maintenance organizations within the Centers for Disease Control and Prevention (CDC) Vaccine Safety Datalink. METHODS: Within every year, each week's vaccinated children were followed for 4 weeks, and rates of adverse events were compared with rates among children of similar ages before the introduction of the new vaccine. We assessed risks for intussusception after rotavirus vaccination and risks for fever, seizures, and other neurologic adverse events after the change from whole cell diphtheria-tetanus-pertussis (DTPw) to acellular DTP vaccine (DTPa). We used sequential probability ratio testing, adjusted for age, sex, calendar time, season, and HMO, and with a stopping value based on the probability of an adverse event under the null hypothesis and under a preset alternative hypothesis. RESULTS: We detected an increase in intussusception after 2589 vaccine doses of rotavirus vaccine, about the same time initial reports of intussusception were made to the Vaccine Adverse Events Reporting System. Decreases in risk for fever, seizures, and other abnormal neurologic events became detectable within 12 weeks, 42 weeks, and 18 months, respectively, after the change from DTPw to DTPa. CONCLUSIONS: We conclude that it is feasible to develop systems for rapid and routine population-based assessments of new vaccine safety.

Databases, Factual↗
PubMed2005

Laboratory monitoring of drugs at initiation of therapy in ambulatory care.

BACKGROUND AND OBJECTIVES: Product labeling and published guidelines reflect the importance of monitoring laboratory parameters for drugs with a risk of organ system toxicity or electrolyte imbalance. Limited information exists about adherence to laboratory monitoring recommendations. The objective of this study was to describe laboratory monitoring among ambulatory patients dispensed medications for which laboratory testing is recommended at therapy initiation. DESIGN AND SUBJECTS: We conducted a retrospective cross-sectional analysis of patients in 10 geographically distributed health maintenance organizations who were newly prescribed medications with recommended laboratory test monitoring. The main outcome measure was the proportion of initial drug dispensing without recommended baseline laboratory monitoring for 35 newly initiated drugs or drug classes. RESULTS: One hundred seven thousand, seven hundred sixty-three of 279,354 (39%) initial drug dispensings occurred without recommended laboratory monitoring. Patients without monitoring were younger than patients who had monitoring (median 57 vs 61 years, P<.001). Thirty-two percent of dispensings where a serum creatinine was indicated did not have it evaluated (range across drugs, 12% to 61%); 39% did not have liver function testing (range 10% to 75%); 32% did not have hematologic monitoring (range 9% to 51%); and 34% did not have electrolyte monitoring (range 20% to 62%) (P<.001). CONCLUSIONS: Substantial opportunity exists to improve laboratory monitoring of drugs for which such monitoring is recommended. This study emphasizes the need for research to identify the clinical implications of not conducting recommended laboratory monitoring, existing barriers to monitoring, and methods to improve practice.

Ambulatory Care↗
PubMed2005

Baseline laboratory monitoring of cardiovascular medications in elderly health maintenance organization enrollees.

OBJECTIVES: To identify correlates of laboratory monitoring errors in elderly health maintenance organization (HMO) members at the initiation of therapy with cardiovascular medications. DESIGN: Cross-sectional study in 10 HMOs. SETTING: United States. PARTICIPANTS: From a 2 million-member sample, individuals aged 65 and older who received one of seven cardiovascular medications (angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), amiodarone, digoxin, diuretics, potassium supplements, and statins) and did not have recommended baseline monitoring performed during the 180 days before or 14 days after the index dispensing. MEASUREMENTS: The proportion of members receiving each drug for whom recommended laboratory monitoring was not performed. Laboratory monitoring error rates stratified by sex, age group, chronic disease score, and HMO site were examined, and logistic regression was used to identify predictors of laboratory monitoring errors. RESULTS: Error rates varied by medication class, ranging from 23% of patients receiving potassium supplementation without serum potassium and serum creatinine monitoring to 58% of patients receiving amiodarone who did not have recommended monitoring for thyroid and liver function. Highest error rates occurred in the youngest elderly for ACE inhibitors, ARBs, digoxin, diuretics, and potassium supplements, although in patients receiving amiodarone and statins, errors were most frequent in the oldest elderly. Errors occurred more frequently in patients with less comorbidity. CONCLUSION: Laboratory monitoring errors occurred frequently in elderly HMO members at the initiation of therapy with cardiovascular medications. Further study must examine the association between these errors and adverse outcomes.

Aged↗
PubMed2005

Potentially inappropriate medication use by elderly persons in U.S. Health Maintenance Organizations, 2000-2001.

OBJECTIVES: To determine rates of potentially inappropriate medication use in elderly persons in managed care plans in the United States in 2000-2001. DESIGN: Cross-sectional study using automated medication-dispensing data. SETTING: Ten geographically distributed health maintenance organizations (HMOs). PARTICIPANTS: One hundred fifty-seven thousand five hundred seventeen members aged 65 years and older enrolled in one of the HMOs. MEASUREMENTS: Prevalence of use of 33 potentially inappropriate medications from January 1, 2000 through June 30, 2001. RESULTS: In 2000-2001, 28.8% (95% confidence interval=28.6-29.1) of elderly individuals received at least one of 33 potentially inappropriate medications. This rate ranged from 23.0% to 36.5% across the 10 HMOs. Approximately 5% of elderly patients received at least one of the 11 medications classified by an expert panel as "always avoid," 13% received at least one of the eight medications that would rarely be considered appropriate, and 17% received at least one of the 14 medications that have some indications but are often misused. Overall, rates of use of these medications were greater in women (32.4%) than in men (24.2%). At least 1% of elderly members received belladonna alkaloids (2.3%), dicyclomine (1.1%), or hyoscyamine (1.2%), each of which multiple expert panels have classified as always inappropriate in patients aged 65 years and older. Seven percent of elderly members received propoxyphene, an analgesic medication considered rarely appropriate in the elderly and a drug that has a long history of limited efficacy and potential for toxicity. CONCLUSION: Recent rates of potentially inappropriate medication use by elderly HMO members were at least as great as in a 1996 national sample. This study highlights the need to understand more fully the rationale behind the continued use of these medications.

Age Distribution↗
PubMed2005

Compliance with national immunization guidelines for children younger than 2 years, 1996-1999.

OBJECTIVES: To evaluate compliance with national immunization guidelines among a large cohort of children cared for at health maintenance organizations (HMOs) and to examine effects on immunization status. METHODS: A cohort study of 176134 children born between January 1, 1994, and December 31, 1997, and monitored from birth to the second birthday was performed. Subjects belonged to the Vaccine Safety Datalink Project, a study of children enrolled in 1 of 4 HMOs. Children were continuously enrolled in a HMO for the first 2 years of life. Prevailing recommendations regarding optimal ages of immunization and intervals between doses were applied to define appropriate immunization timing and immunization status. Noncompliance was defined as having a missing or late immunization or an immunization error. Immunization errors included invalid immunizations (too early to be acceptable), extra immunizations (superfluous immunizations or make-up immunizations for invalid immunizations), and missed opportunities resulting in late or missing immunizations. RESULTS: Although 75.4% of children in these HMOs were up to date for all immunizations at 2 years, only 35.6% of children were fully compliant with recommended immunization practices. Less than 8% of children received all immunizations in accordance with strict interpretation of recommended guidelines. Fifty-one percent of children had at least 1 immunization error by age 2 years; 29.7% had a missed opportunity with subsequent late or missing immunization, 20.4% had an invalid immunization, and 11.6% had an extra immunization. Common reasons for noncompliance included missed opportunities for the fourth Haemophilus influenzae type b vaccine (14.6%), invalid fourth diphtheria-tetanus-pertussis/acellular pertussis immunizations (11.0%), and superfluous polio immunizations (9.8%). CONCLUSIONS: Approximately 35.6% of children were compliant with prevailing childhood immunization recommendations from 1996 to 1999. Efforts to improve compliance with guidelines are recommended, to optimize childhood infectious disease prevention.

Cohort Studies↗
PubMed2005

Association between streptococcal infection and obsessive-compulsive disorder, Tourette's syndrome, and tic disorder.

OBJECTIVE: Reports have suggested that streptococcal infection may be etiologically related to pediatric autoimmune neuropsychiatric disorders (PANDAS), but there are few good epidemiologic studies to support this theory. Using population-based data from a large West-Coast health maintenance organization, we assessed whether streptococcal infection was associated with increased risk for obsessive-compulsive disorder (OCD), Tourette's syndrome (TS), or tic disorder. METHODS: This is a case-control study of children 4 to 13 years old receiving their first diagnosis of OCD, TS, or tic disorder between January 1992 and December 1999 at Group Health Cooperative outpatient facilities. Cases were matched to controls by birth date, gender, primary physician, and propensity to seek health care. RESULTS: Patients with OCD, TS, or tic disorder were more likely than controls to have had prior streptococcal infection (OR: 2.22; 95% CI: 1.05, 4.69) in the 3 months before onset date. The risk was higher among children with multiple streptococcal infections within 12 months (OR: 3.10; 95% CI: 1.77, 8.96). Having multiple infections with group A beta-hemolytic streptococcus within a 12-month period was associated with an increased risk for TS (OR: 13.6; 95% CI: 1.93, 51.0). These associations did not change appreciably when limited to cases with a clear date of onset of symptoms or with tighter matching on health care behavior. CONCLUSION: These findings lend epidemiologic evidence that PANDAS may arise as a result of a postinfectious autoimmune phenomenon induced by childhood streptococcal infection.

Adolescent↗