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Robert L Davis

Publications and source records attributed to Robert L Davis.

At least 37 records · Page 2Linked to original sources
PubMed2004

Intussusception and oral poliovirus vaccination: is there an association?

Oral rotavirus vaccine was voluntarily withdrawn from the market after studies observed an increased risk of intussusception within 2 weeks after immunization. Concern has been raised that other orally administered vaccines, such as oral poliovirus vaccine (OPV), may also be associated with intussusception. In this 1990-1998 case-control study, the authors examined the association between OPV and intussusception in the Washington State Medicaid population, evaluating receipt of OPV during the month prior to intussusception among 119 cases and 589 controls matched by date of birth. Analysis was conducted via matched conditional logistic regression, controlling for sex. Between 1990 and 1998, 119 children younger than age 2 years had a therapeutic enema, surgical reduction, or hospitalization for intussusception and had been enrolled in Medicaid for at least 1 month prior to their intussusception date. There was no significantly elevated risk of intussusception associated with receipt of OPV; 9.2% (11/119) of cases and 8.5% (50/589) of controls were given OPV 0-28 days prior to the case's intussusception date (odds ratio=1.1, 95% confidence interval: 0.5, 2.2). However, to address the hypothesis that risk of intussusception is related to receipt of a particular dose of OPV, a larger study would be required.

Age Distribution↗
PubMed2004

Post-marketing evaluation of the short term safety of COMVAX.

We report an evaluation of the short-term safety of a pediatric bivalent combination vaccine containing RECOMBIVAXHB and Liquid PedvaxHIB, COMVAX. Safety was assessed through identification of medical utilization; potential adverse events were identified through computerized clinical databases for deaths, hospitalizations, emergency room visits, and outpatient clinic visits. We calculated relative risks whenever there was at least one diagnosis-specific event in the risk period following vaccination and compared the rates in specific time windows following vaccination with rates at 31-60 days following vaccination and also with rates in a historical cohort of children. A total of 27,802 doses of COMVAX were administered, with 127 separate adverse event codes with statistically significant elevated risks, and 66 codes with significantly decreased risks. Most potentially serious diagnoses appeared in four major categories: "Respiratory Events"; "Gastroenteritis"; "Adverse Effect of Medicinal and Biological Substance, NOS"; and "Fever". There was no consistent pattern to indicate increased risks for serious respiratory or gastrointestinal illness. For fever, most of the findings appeared to be explained by changes in data collection or by concomitant vaccination with M-M-R(-)II. There was an increased risk for fever hospitalizations following shot 1. The total number of children hospitalized with fever was seven out of 12,468 children; all recovered fully. In this study population of 27,802 vaccine recipients, COMVAX appeared to have a favorable safety profile.

Female↗
PubMed2004

Safety of the trivalent inactivated influenza vaccine among children: a population-based study.

BACKGROUND: To our knowledge, there are no published population-based studies on the safety of the inactivated trivalent influenza vaccine among children. OBJECTIVE: To screen a large population of children for evidence of increased medical visits in the 2 weeks after influenza vaccination compared with 2 control periods. Secondary analyses included shorter risk periods and restricted age categories. DESIGN: Self-control screening analysis. Children vaccinated from January 1, 1993, through December 31, 1999, were randomly divided into 2 equal groups. In group 1, risks of outpatient, emergency department, and inpatient visits during the 14 days after vaccination were compared with the risks of visits in 2 control periods. Significant plausible medically attended events identified in group 1 were then analyzed in group 2, using the same 2 control periods. Medically attended events significant in both groups were considered potentially associated with vaccination and were assessed by medical record review. SETTING: Five managed care organizations in the United States. PARTICIPANTS: Children younger than 18 years who received an influenza vaccination in one of the managed care settings (N = 251 600). MAIN OUTCOME MEASURE: Among vaccinated children seen for a medically attended event, the odds of the visit occurring in the 2 weeks after vaccination vs during 1 of the 2 control periods. RESULTS: Study participants incurred 1165, 230, and 489 different diagnoses during the 14 days after vaccination according to the outpatient, emergency department, and inpatient data, respectively. Four diagnoses were positively associated with the vaccine in both groups 1 and 2: impetigo, dermatitis, uncomplicated diabetes mellitus, and ureteral disorder not otherwise specified. After medical record review, impetigo (9 cases) in children 6 to 23 months old remained significantly associated with vaccination. CONCLUSION: This large screening safety study did not reveal any evidence of important medically attended events associated with pediatric influenza vaccination.

Case-Control Studies↗
PubMed2004

Use of a respiratory clinical score among different providers.

Respiratory assessment of children with asthma or bronchiolitis is problematic because both the components of the assessment and their relative importance vary among care providers. Use of a systematic standard assessment process and clinical score may reduce interobserver variation. Our objective was to determine observer agreement among physicians (MD), nurses (RN), and respiratory therapists (RT), using a standard respiratory clinical score. A clinical score was developed incorporating four physiologic parameters: respiratory rate, retractions, dyspnea, and auscultation. One hundred and sixty-five provider pairs (e.g., MD-MD, RN-RT) independently assessed a total of 55 patients admitted for asthma, bronchiolitis, or wheezing at an urban tertiary-care hospital. A weighted kappa statistic measured agreement beyond chance. Rater pairs had high observed agreement on total score of 82-88% and weighted kappas ranging from 0.52 (MD-RN; 95% CI, 0.19, 0.79) to 0.65 (RN-RN; 95% CI, 0.46, 0.87). Observed agreement on individual components of the score ranged from 58% (auscultation) to 74% (dyspnea), with unweighted kappas of 0.36 (respiratory rate; 95% CI, 0.26, 0.46) to 0.53 (dyspnea; 95% CI, 0.41, 0.65). In conclusion, this respiratory clinical score demonstrates good interobserver agreement between MDs, RNs, and RTs. Future research is needed to examine validity and responsiveness in clinical settings. By standardizing respiratory assessments, use of a clinical score may facilitate care coordination by physicians, nurses, and respiratory therapists and thereby improve care of children hospitalized with asthma and bronchiolitis.

Adolescent↗
PubMed2004

Prescription drug use in pregnancy.

OBJECTIVE: The purpose of this study was to provide information on the prevalence of the use of prescription drugs among pregnant women in the United States. STUDY DESIGN: A retrospective study was conducted with the use of the automated databases of 8 health maintenance organizations that are involved in the Health Maintenance Research Network Center for Education and Research on Therapeutics. Women who delivered of an infant in a hospital from January 1, 1996, through December 31, 2000, were identified. Prescription drug use according to therapeutic class and the United States Food and Drug Administration risk classification system was evaluated, with the assumption of a gestational duration of 270 days, with three 90-day trimesters of pregnancy, and with a 90-day period before pregnancy. Nonprescription drug use was not assessed. RESULTS: During the period 1996 through 2000, 152,531 deliveries were identified that met the criteria for study. For 98,182 deliveries (64%), a drug other than a vitamin or mineral supplement was prescribed in the 270 days before delivery: 3595 women (2.4%) received a drug from category A; 76,292 women (50.0%) received a drug from category B; 57,604 women (37.8%) received a drug from category C; 7333 women (4.8%) received a drug from category D, and 6976 women (4.6%) received a drug from category X of the United States Food and Drug Administration risk classification system. Overall, 5157 women (3.4%) received a category D drug, and 1653 women (1.1%) received a category X drug after the initial prenatal care visit. CONCLUSION: Our finding that almost one half of all pregnant women received prescription drugs from categories C, D, or X of the United States Food and Drug Administration risk classification system highlights the importance of the need to understand the effects of these medications on the developing fetus and on the pregnant woman.

Databases, Factual↗
PubMed2004

Epidemiology of anaphylaxis among children and adolescents enrolled in a health maintenance organization.

BACKGROUND: There is little information about the incidence of anaphylaxis from all causes. OBJECTIVE: The objects of this study were (1) to estimate the incidence of anaphylaxis; (2) to explore the range of diagnoses attributed to an anaphylactic episode; and (3) to describe the clinical features of anaphylaxis. METHODS: The study population consisted of children and adolescents enrolled at a health maintenance organization. We identified potential episodes of anaphylaxis occurring between 1991 and 1997 from automated databases and reviewed the medical record to confirm the diagnosis. We reviewed all diagnoses specific for anaphylaxis (eg, ICD-9 995.0, anaphylactic shock) and sampled from among other related diagnoses (eg, ICD-9 995.3, allergy unspecified). Estimation of the incidence of provider-diagnosed anaphylaxis was based on cases confirmed from among the specific diagnosis codes. Description of the clinical features of anaphylaxis involved all confirmed cases regardless of diagnosis. RESULTS: We identified 67 episodes of anaphylaxis among children with diagnosis codes specific for anaphylaxis (10.5 episodes per 100,000 person-years). There was no increase in incidence over time. Review of samples of diagnoses not specific for anaphylaxis yielded an additional 18 episodes. Among all identified episodes (n = 85), mucocutaneous and respiratory manifestations were the most common. Seventy-one percent of episodes were treated in the emergency department. Nine episodes (11%) resulted in hospitalization. CONCLUSIONS: The incidence of anaphylaxis did not increase during these years. A majority of episodes were treated in the emergency department. Anaphylaxis in this population was frequently diagnosed as another related condition, and the basis and implications of diagnostic practices in this disorder warrant further exploration.

Adolescent↗
PubMed2003

Polio extraimmunization in children younger than 2 years after changes in immunization recommendations.

OBJECTIVE: To investigate trends over time in polio extraimmunization among children in 4 large health maintenance organizations and to study the association with recent changes in polio immunization policy. METHODS: Using 176 169 children who were born after 1994 and enrolled for their first 2 years of life, we assessed rates and trends of polio extraimmunization in the Vaccine Safety Datalink project. We used logistic regression to test the association of extraimmunization with different polio immunization schedules and with sociodemographic characteristics and used Poisson regression to test changes in rates over time. RESULTS: Overall, 10.5% were extraimmunized for poliovirus; children on the all inactivated polio virus or sequential schedule were one half as likely as those on the all oral polio virus schedule to be extraimmunized by 2 years of age. There was a significant decrease in extraimmunization over time, with <5% of children born at the end of 1997 being extraimmunized, compared with >15% at the beginning of 1994. CONCLUSIONS: Poliovirus extraimmunization rates have fallen dramatically in association with the change-over to the all inactivated polio virus schedule.

Administration, Oral↗
PubMed2003

Risk of anaphylaxis after vaccination of children and adolescents.

OBJECTIVE: To quantify the risk of anaphylaxis after vaccination of children and adolescents. METHODS: The study population consisted of children and adolescents who were enrolled at 4 health maintenance organizations that participated in the Vaccine Safety Datalink Project. For the period 1991-1997, we identified potential cases by searching for occurrences of International Classification of Diseases, Ninth Revision (ICD-9) code 995.0 (anaphylactic shock), E948.0 through E948.9 (adverse reaction from bacterial vaccines), and E949.0 through E949.9 (adverse reaction from other vaccines and biological substances). At 1 study site, we also included a range of other allergy codes. We restricted to diagnoses on days 0 to 2 after vaccination (ICD-9 995.0) or day 0 (all other ICD-9 codes). We then reviewed the medical record to confirm the diagnosis. RESULTS: We identified 5 cases of potentially vaccine-associated anaphylaxis after administration of 7 644 049 vaccine doses, for a risk of 0.65 cases/million doses (95% confidence interval: 0.21-1.53). None of the episodes resulted in death. Vaccines that were administered before the anaphylactic episodes were generally given in combination and included measles-mumps-rubella, hepatitis B, diphtheria-tetanus, diphtheria-tetanus-pertussis, Haemophilus influenzae type b, and oral polio vaccine. One case of anaphylaxis followed measles-mumps-rubella vaccine alone. At the site at which we reviewed additional allergy codes, we identified 1 case after 653 990 vaccine doses, for a risk of 1.53 cases/million doses (95% confidence interval: 0.04-8.52). CONCLUSIONS: Patients and health care providers can be reassured that vaccine-associated anaphylaxis is a rare event. Nevertheless, providers should be prepared to provide immediate medical treatment should it occur.

Adolescent↗
PubMed2003

Placing the risk of seizures with pediatric vaccines in a clinical context.

In this review we discuss the relationship between commonly administered childhood vaccines such as diphtheria-tetanus-whole cell pertussis (DTP) and measles-mumps-rubella (MMR), and the risk of nonfebrile and febrile seizure. We summarize data from the Vaccine Safety Datalink Study and other studies that suggest that DTP and MMR vaccine are associated with a transiently increased risk of febrile seizures, and cause between 5-9 and 25-34 additional extra febrile seizures per 100 000 immunized children, respectively. DTP and MMR do not appear to increase the risk of nonfebrile seizures. We discuss some methodologic challenges in studies of vaccines and seizures. Because there is no adequate comparison group that would allow for the study of seizures long after vaccination, studies of seizures are limited to acute events shortly following vaccination. Additionally, while seizures following vaccination are worrisome to parents and physicians alike, observational studies of the neurodevelopmental outcomes of these children are particularly problematic. We discuss how such studies are confounded by the natural history of predisposition to febrile seizures and by the increased diagnostic scrutiny that children with febrile seizures might undergo. Nevertheless, current data suggest that children with febrile seizures do not experience long-term negative effects.Finally, we discuss the creation of new clinics designed specifically to assist physicians in managing the vaccination of children with a personal or family history of seizures. Data from these clinics suggest that vaccination is safe for children with a personal or family history of seizures, but statistical power has been limited. We conclude by discussing the introduction of new vaccines, and note that, even with widespread use, it will take many years before we can be knowledgeable about the risk of rare events with these newly licensed products.

Child↗
PubMed2003

Safety of thimerosal-containing vaccines: a two-phased study of computerized health maintenance organization databases.

OBJECTIVE: To assess the possible toxicity of thimerosal-containing vaccines (TCVs) among infants. METHODS: A 2-phased retrospective cohort study was conducted using computerized health maintenance organization (HMO) databases. Phase I screened for associations between neurodevelopmental disorders and thimerosal exposure among 124 170 infants who were born during 1992 to 1999 at 2 HMOs (A and B). In phase II, the most common disorders associated with exposure in phase I were reevaluated among 16 717 children who were born during 1991 to 1997 in another HMO (C). Relative risks for neurodevelopmental disorders were calculated per increase of 12.5 micro g of estimated cumulative mercury exposure from TCVs in the first, third, and seventh months of life. RESULTS: In phase I at HMO A, cumulative exposure at 3 months resulted in a significant positive association with tics (relative risk [RR]: 1.89; 95% confidence interval [CI]: 1.05-3.38). At HMO B, increased risks of language delay were found for cumulative exposure at 3 months (RR: 1.13; 95% CI: 1.01-1.27) and 7 months (RR: 1.07; 95% CI: 1.01-1.13). In phase II at HMO C, no significant associations were found. In no analyses were significant increased risks found for autism or attention-deficit disorder. CONCLUSIONS: No consistent significant associations were found between TCVs and neurodevelopmental outcomes. Conflicting results were found at different HMOs for certain outcomes. For resolving the conflicting findings, studies with uniform neurodevelopmental assessments of children with a range of cumulative thimerosal exposures are needed.

Cohort Studies↗
PubMed2002

Barriers to implementing the group B streptococcal prevention guidelines.

BACKGROUND: Group B streptococcal disease is the leading cause of neonatal sepsis in the United States. We assessed predictors of compliance with the consensus guidelines for perinatal group B streptococcus disease prevention at two Group Health Cooperative hospitals. METHODS: A descriptive and cohort analysis was conducted of failure to comply with the screening-based approach to group B streptococcus prevention among singleton birth pregnancies in two Group Health Cooperative hospitals, September 1, 1996 to December 31, 1997. We studied determinants of failure to screen pregnant women for group B streptococcus at 35 to 37 weeks' gestation and failure to deliver intrapartum antibiotic prophylaxis to Group B streptococcus-positive women. RESULTS: Nearly 28 percent of 1969 women delivering at two Group Health Cooperative hospitals were not screened appropriately for group B streptococcus. Women who were not screened properly were more likely to be in their teens. A short length of hospital stay before delivery was the strongest predictor of the lack of administration of intrapartum antibiotic prophylaxis to infected multiparas at delivery. Group B streptococcus-positive women without pregnancy complications were less likely to receive intrapartum antibiotic prophylaxis than infected women with complications. CONCLUSIONS: The findings of this study suggest that to improve group B streptococcus disease prevention, screening efforts should focus on teenage women, and intrapartum antibiotic prophylaxis delivery efforts should be aimed at low-risk women with precipitous labor.

Adolescent↗
PubMed2002

Childhood vaccinations and risk of asthma.

BACKGROUND: A few previous studies have suggested that childhood vaccines, particularly whole cell pertussis vaccine, may increase the risk of asthma. We evaluated the suggested association between childhood vaccinations and risk of asthma. METHODS: Cohort study involving 167,240 children who were enrolled in 4 large health maintenance organizations during 1991 to 1997, with follow-up from birth until at least 18 months to a maximum of 6 years of age. Vaccinations were ascertained through computerized immunization tracking systems, and onset of asthma was identified through computerized data on medical care encounters and medication dispensings. RESULTS: In the study 18,407 children (11.0%) developed asthma, with a median age at onset of 11 months. The relative risks (95% confidence intervals) of asthma were: 0.92 (0.83 to 1.02) for diphtheria, tetanus and whole cell pertussis vaccine; 1.09 (0.9 to 1.23) for oral polio vaccine; 0.97 (0.91 to 1.04) for measles, mumps and rubella (MMR) vaccine; 1.18 (1.02 to 1.36) for Haemophilus influenzae type b (Hib); and 1.20 (1.13 to 1.27) for hepatitis B vaccine. The Hib result was not consistent across health maintenance organizations. In a subanalysis restricted to children who had at least 2 medical care encounters during their first year, the relative risks decreased to 1.07 (0.71 to 1.60) for Hib and 1.09 (0.88 to 1.34) for hepatitis B vaccine. CONCLUSION: There is no association between diphtheria, tetanus and whole cell pertussis vaccine, oral polio vaccine or measles, mumps and rubella vaccine and the risk of asthma. The weak associations for Hib and hepatitis B vaccines seem to be at least partially accounted for by health care utilization or information bias.

Asthma↗
PubMed2002

Outcomes of prenatal antidepressant exposure.

OBJECTIVE: This study evaluated the effects of prenatal antidepressant exposure on perinatal outcomes, congenital malformations, and early growth and development. METHOD: Within a group-model health maintenance organization, all infants with apparent prenatal exposure to tricyclic or selective serotonin reuptake inhibitor (SSRI) antidepressants were frequency matched to an unexposed comparison group by year of birth, maternal age, and mother's lifetime use of antidepressant drugs and mental health care. A structured blind review of mothers' and infants' medical records examined perinatal outcomes, congenital malformations, and developmental delay. RESULTS: Tricyclic antidepressant exposure was not associated with any significant difference in perinatal outcomes. Exposure to SSRIs was associated with a 0.9-week decrease in mean gestational age, a 175-g decrease in mean birth weight, and a 0.29 decrease in mean Apgar score at 5 minutes, but differences in birth weights and Apgar scores were not significant after adjustment for gestational age. Differences in gestational age and birth weights were unrelated to length of exposure, but differences in Apgar scores were limited to those with third-trimester exposure. Neither tricyclic antidepressant nor SSRI exposure was significantly associated with congenital malformations or developmental delay. CONCLUSIONS: The authors found no association between tricyclic antidepressant or SSRI exposure and either congenital malformations or developmental delay. SSRI exposure during pregnancy was associated with earlier delivery and consequent lower birth weight. Third-trimester SSRI exposure was also associated with lower Apgar scores. Women considering taking SSRIs during pregnancy may balance any higher fetal risk against the risk of persistent or recurrent depression.

Adult↗