We sought to measure trends in Streptococcus pneumoniae (SP) carriage and antibiotic resistance in young children in Massachusetts communities after widespread adoption of heptavalent pneumococcal conjugate vaccine (PCV7) and before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13).
We conducted a cross-sectional study including collection of questionnaire data and nasopharyngeal specimens among children <7 years in primary care practices from 8 Massachusetts communities during the winter season of 2008–9 and compared with to similar studies performed in 2001, 2003–4, and 2006–7. Antimicrobial susceptibility testing and serotyping were performed on pneumococcal isolates, and risk factors for colonization in recent seasons (2006–07 and 2008–09) were evaluated.
We collected nasopharyngeal specimens from 1,011 children, 290 (29%) of whom were colonized with pneumococcus. Non-PCV7 serotypes accounted for 98% of pneumococcal isolates, most commonly 19A (14%), 6C (11%), and 15B/C (11%). In 2008–09, newly-targeted PCV13 serotypes accounted for 20% of carriage isolates and 41% of penicillin non-susceptible S. pneumoniae (PNSP). In multivariate models, younger age, child care, young siblings, and upper respiratory illness remained predictors of pneumococcal carriage, despite near-complete serotype replacement. Only young age and child care were significantly associated with PNSP carriage.
Serotype replacement post-PCV7 is essentially complete and has been sustained in young children, with the relatively virulent 19A being the most common serotype. Predictors of carriage remained similar despite serotype replacement. PCV13 may reduce 19A and decrease antibiotic-resistant strains, but monitoring for new serotype replacement is warranted.
Streptococcus pneumoniae; pneumococcal conjugate vaccine; antibiotic resistance; serotype; colonization
MLST; conjugate vaccination; Streptococcus pneumoniae; nasopharyngeal carriage
The inflammatory bowel diseases (IBDs), Crohn’s disease (CD) and ulcerative colitis (UC) affect over 1 million people in the United States, yet little is known about healthcare utilization by affected individuals.
1) To describe the healthcare utilization associated with IBD in an insured U.S. population. 2) To determine how sociodemographic factors impact healthcare utilization in this population.
Using an administrative database comprised of 87 health plans, we ascertained cases of CD and UC using an administrative definition. We identified inpatient, office-based, emergency, and endoscopy services occurring between 2003-2004 in IBD patients and matched controls. For each case, excess utilization was determined by subtracting the mean number of control visits from the number of case visits. Multivariable logistic and linear regressions were used to identify the sociodemographic factors associated with excess utilization.
We identified 9,056 CD patients and 10,364 UC patients. The mean number of annual excess hospitalizations, ED visits, and office visits per 100 patients for CD were 21.7, 20.1, and 493 respectively. These values for UC were 13.3, 10.3, and 364 respectively. In general, utilization was higher in CD compared with UC, and in younger patients compared with older patients. Utilization also varied by gender, geographical region, and insurance type (Medicaid versus commercial).
In the U.S., patients with IBD consume substantial healthcare resources. Resource utilization varies by patient age and disease type, and to a lesser extent, gender, geographical region, and insurance type. These findings may be used to inform health policy.
Crohn’s disease; ulcerative colitis; healthcare utilization
Defining the propensity of Streptoccocus pneumoniae (SP) serotypes to invade sterile body sites following nasopharyngeal (NP) acquisition has the potential to inform about how much invasive pneumococcal disease (IPD) may occur in a typical population with a given distribution of carriage serotypes. Data from enhanced surveillance for IPD in Massachusetts children ≤7 years in 2003/04, 2006/07 and 2008/09 seasons and surveillance of SP NP carriage during the corresponding respiratory seasons in 16 Massachusetts communities in 2003/04 and 8 of the 16 communities in both 2006/07 and 2008/09 were used to compute a serotype specific “invasive capacity (IC)” by dividing the incidence of IPD due to serotype x by the carriage prevalence of that same serotype in children of the same age. A total of 206 IPD and 806 NP isolates of SP were collected during the study period. An approximate 50-fold variation in the point estimates between the serotypes having the highest (18C, 33F, 7F, 19A, 3 and 22F) and lowest (6C, 23A, 35F, 11A, 35B, 19F, 15A, and 15BC) IC was observed. Point estimates of IC for most of the common serotypes currently colonizing children in Massachusetts were low and likely explain the continued reduction in IPD from the pre-PCV era in the absence of specific protection against these serotypes. Invasive capacity differs among serotypes and as new pneumococcal conjugate vaccines are introduced, ongoing surveillance will be essential to monitor whether serotypes with high invasive capacity emerge (e.g. 33F, 22F) as successful colonizers resulting in increased IPD incidence due to replacement serotypes.
Streptoccocus pneumoniae; serotype; invasive capacity
Pneumococcal type 1 pilus proteins have been proposed as potential vaccine candidates. Following conjugate pneumococcal vaccination, the prevalence of the pneumococcal type 1 pilus declined dramatically, a decline associated with the elimination of vaccine-type (VT) strains. Here we show that between 2004 and 2007, there has been a significant increase in pilus prevalence, now exceeding rates from the pre-conjugate vaccine era. This increase is primarily due to non-VT strains. These emerging piliated non-VT strains are mostly novel clones, with some exceptions. The rise in pilus type 1 frequency across multiple distinct genetic backgrounds suggests that the pilus may confer an intrinsic advantage.
S. pneumoniae pilus; PCV7; vaccine- and non-vaccine-types
Invasive pneumococcal disease (IPD) has been reduced in the US following conjugate vaccination (PCV7) targeting seven pneumococcal serotypes in 2000. However, increases in IPD due to other serotypes have been observed, in particular 19A. How much this “serotype replacement” will erode the benefits of vaccination and over what timescale is unknown. We used a population genetic approach to test first whether the selective impact of vaccination could be detected in a longitudinal carriage sample, and secondly how long it persisted for following introduction of vaccine in 2000. To detect the selective impact of the vaccine we compared the serotype diversity of samples from pneumococcal carriage in Massachusetts children collected in 2001, 2004 and 2007 with others collected in the pre-vaccine era in Massachusetts, the UK and Finland. The 2004 sample was significantly (p >0.0001) more diverse than pre-vaccine samples, indicating the selective pressure of vaccination. The 2007 sample showed no significant difference in diversity from the pre-vaccine period, and exhibited similar population structure, but with different serotypes. In 2007 the carriage frequency of 19A was similar to that of the most common serotype in pre-vaccine samples. We suggest that serotype replacement involving 19A may be complete in Massachusetts due to similarities in population structure to pre-vaccine samples. These results suggest that the replacement phenomenon occurs rapidly with high vaccine coverage, and may allay concerns about future increases in disease due to 19A. For other serotypes, the future course of replacement disease remains to be determined.
Streptococcus pneumoniae; Infectious disease epidemiology; Nasopharyngeal carriage; Population genetics
The majority of infants in the United States are in non-parental child care, yet little is known about the effect of child care on development of obesity.
To examine the relationship between child care attendance from birth to 6 months and adiposity at 1 and 3 years of age.
We studied 1138 children from a prospective cohort of pregnant women and their offspring. The main exposure was time in child care from birth to 6 months of age, overall and by type of care: (1) child care center; (2) someone else’s home; and (3) child’s own home by nonparent. The main outcomes were weight-for-length (WFL) z score at 1 year and BMI z score at 3 years of age.
A total of 649 (57%) infants attended child care; 17% were cared for in a center, 27% in someone else’s home, and 21% in their own home by a nonparent. After adjustment for confounders, overall time in child care was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age but not skinfold thicknesses. Center and own home care were not associated with the outcomes, but care in someone else’s home was associated with an increase in both the 1- and 3-year outcomes.
Child care in the first 6 months of life, especially in someone else’s home, was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age.
child care; childhood obesity; nutrition; physical activity; infancy
Prescription drug costs are a major component of health care expenditures, yet resources to support evidence-based prescribing are not widely available.
To evaluate the effectiveness of computerized prescribing alerts, with or without physician-led group educational sessions, to reduce the prescribing of heavily marketed hypnotic medications.
Cluster-randomized controlled trial.
We randomly allocated 14 internal medicine practice sites to receive usual care, computerized prescribing alerts alone, or alerts plus group educational sessions.
Proportion of heavily marketed hypnotics prescribed before and after the implementation of computerized alerts and educational sessions.
The activation of computerized alerts held the prescribing of heavily marketed hypnotic medications at pre-intervention levels in both the alert-only group (adjusted risk ratio [RR] 0.97; 95% CI 0.82–1.14) and the alert-plus-education group (RR 0.98; 95% CI 0.83–1.17) while the usual-care group experienced an increase in prescribing (RR 1.31; 95% CI 1.08–1.60). Compared to the usual-care group, the relative risk of prescribing heavily marketed medications was less in both the alert-group (Ratio of risk ratios [RRR] 0.74; 95% CI 0.57–0.96) and the alert-plus-education group (RRR 0.74; 95% CI 0.58–0.97). The prescribing of heavily marketed medications was similar in the alert-group and alert-plus-education group (RRR 1.02; 95% CI 0.80–1.29). Most clinicians reported that the alerts provided useful prescribing information (88%) and did not interfere with daily workflow (70%).
Computerized decision support is an effective tool to reduce the prescribing of heavily marketed hypnotic medications in ambulatory care settings.
clinicaltrials.gov Identifier: NCT00788346.
Electronic supplementary material
The online version of this article (doi:10.1007/s11606-009-1013-x) contains supplementary material, which is available to authorized users.
prescription drugs; effectiveness; marketed medications; prescribing; decision support; computerized alerts
The goals were to assess serial changes in Streptococcus pneumoniae serotypes and antibiotic resistance in young children and to evaluate whether risk factors for carriage have been altered by heptavalent pneumococcal conjugate vaccine (PCV7).
Nasopharyngeal specimens and questionnaire/medical record data were obtained from children 3 months to <7 years of age in primary care practices in 16 Massachusetts communities during the winter seasons of 2000–2001 and 2003–2004 and in 8 communities in 2006–2007. Antimicrobial susceptibility testing and serotyping were performed with S pneumoniae isolates.
We collected 678, 988, and 972 specimens during the sampling periods in 2000–2001, 2003–2004, and 2006–2007, respectively. Carriage of non-PCV7 serotypes increased from 15% to 19% and 29% (P < .001), with vaccine serotypes decreasing to 3% of carried serotypes in 2006–2007. The relative contribution of several non-PCV7 serotypes, including 19A, 35B, and 23A, increased across sampling periods. By 2007, commonly carried serotypes included 19A (16%), 6A (12%), 15B/C (11%), 35B (9%), and 11A (8%), and high-prevalence serotypes seemed to have greater proportions of penicillin nonsusceptibility. In multivariate models, common predictors of pneumococcal carriage, such as child care attendance, upper respiratory tract infection, and the presence of young siblings, persisted.
The virtual disappearance of vaccine serotypes in S pneumoniae carriage has occurred in young children, with rapid replacement with penicillin-nonsusceptible nonvaccine serotypes, particularly 19A and 35B. Except for the age group at highest risk, previous predictors of carriage, such as child care attendance and the presence of young siblings, have not been changed by the vaccine.
Streptococcus pneumoniae; pneumococcal conjugate vaccine; antibiotic resistance; serotype; colonization
Because pneumococcal serotype 6C was previously not distinguished from serotype 6A, the impact of the 7-valent pneumococcal conjugate vaccine (PCV7) on the carriage of serotype 6C is unknown.
The nasopharyngeal (NP) prevalence of the 6C serotype was determined using 1326 pneumococcal isolates collected from 7 cohorts of Massachusetts children between 1994 and 2007. Initially, the isolates were serotyped using the quellung reaction; subsequently, stored specimens of all putative 6A isolates were tested for 6C using monoclonal antibodies. The opsonophagocytic and antibiotic susceptibilities of the isolates were determined.
The prevalence of 6A was 9.6% (33/343) before 2001, 8.0% (18/226) in 2004, and 2.9% (12/416) in 2007. In contrast, the prevalence of 6C was 0.6% (2/343) before 2001, 2.2% (5/226) in 2004, and 8.7% (36/416) in 2007 (P < .001 for 2/343 vs. 36/416). 6C isolates from 2007 were more susceptible to antibiotics than were 6A isolates. PCV7 induced a low ability to opsonize different isolates of 6C.
Among NP isolates, the prevalence of 6C isolates has increased and the prevalence of 6A isolates has decreased since the introduction of PCV7 in Massachusetts in 2000. The observed increase in serotype 6C prevalence may be explained by the induction by PCV7 of low amounts of functional anti-6C antibody, compared with anti-6A and anti-6B antibodies.
Data regarding the health care costs of inflammatory bowel disease (IBD) in the United States are limited.
1) To estimate the direct costs of Crohn’s disease (CD) and ulcerative colitis (UC) in the U.S. 2) To describe the distribution of costs between inpatient, outpatient, and pharmaceutical services, and 3) To identify sociodemographic factors influencing these costs.
We extracted medical and pharmacy claims from an administrative database containing insurance claims from 87 health plans in 33 states, occurring between the years 2003–2004. We identified cases of CD and UC using an administrative definition. For each case, we selected up to 3 non-IBD controls. Claims were classified as inpatient, outpatient, or pharmaceutical according to Current Procedural Terminology or National Drug Codes. Costs were based on the paid amount of each claim. IBD-attributable costs were estimated by subtracting costs for non-IBD patients from those with IBD. Logistic regression was used to identify the sociodemographic factors affecting these costs.
We identified 9,056 CD patients and 10,364 UC patients. Mean annual costs for CD and UC were $8265 and $5066 respectively. For CD, 31% of costs were attributable to hospitalization, 33% to outpatient care, and 35% to pharmaceutical claims. The corresponding distribution for UC was 38%, 35%, and 27% respectively. Costs were significantly higher for children age < 20, compared to adults, but did not vary substantially by gender or region.
This study demonstrates a substantial economic burden of IBD and can be used to inform health policy.
The incidence of community-associated methicillin-resistant Staphylococcus aureus (MRSA) has risen dramatically in the U.S., particularly among children. Although Streptococcus pneumoniae colonization has been inversely associated with S. aureus colonization in unvaccinated children, this and other risk factors for S. aureus carriage have not been assessed following widespread use of the heptavalent pneumococcal conjugate vaccine (PCV7). Our objectives were to (1) determine the prevalence of S. aureus and MRSA colonization in young children in the context of widespread use of PCV7; and (2) examine risk factors for S. aureus colonization in the post-PCV7 era, including the absence of vaccine-type S. pneumoniae colonization.
Swabs of the anterior nares (S. aureus) were obtained from children enrolled in an ongoing study of nasopharyngeal pneumococcal colonization of healthy children in 8 Massachusetts communities. Children 3 months to <7 years of age seen for well child or sick visits in primary care offices from 11/03–4/04 and 10/06–4/07 were enrolled. S. aureus was identified and antibiotic susceptibility testing was performed. Epidemiologic risk factors for S. aureus colonization were collected from parent surveys and chart reviews, along with data on pneumococcal colonization. Multivariate mixed model analyses were performed to identify factors associated with S. aureus colonization.
Among 1,968 children, the mean age (SD) was 2.7 (1.8) years, 32% received an antibiotic in the past 2 months, 2% were colonized with PCV7 strains and 24% were colonized with non-PCV7 strains. The prevalence of S. aureus colonization remained stable between 2003–04 and 2006–07 (14.6% vs. 14.1%), while MRSA colonization remained low (0.2% vs. 0.9%, p = 0.09). Although absence of pneumococcal colonization was not significantly associated with S. aureus colonization, age (6–11 mo vs. ≥5 yrs, OR 0.39 [95% CI 0.24–0.64]; 1–1.99 yrs vs. ≥5 yrs, OR 0.35 [0.23–0.54]; 2–2.99 yrs vs. ≥5 yrs, OR 0.45 [0.28–0.73]; 3–3.99 yrs vs. ≥5 yrs, OR 0.53 [0.33–0.86]) and recent antibiotic use were significant predictors in multivariate models.
In Massachusetts, S. aureus and MRSA colonization remained stable from 2003–04 to 2006–07 among children <7 years despite widespread use of pneumococcal conjugate vaccine. S. aureus nasal colonization varies by age and is inversely correlated with recent antibiotic use.
To assess the practice-level effects of (1) a physician peer leader intervention and (2) peer leaders in combination with the introduction of asthma education nurses to facilitate care improvement. And, to compare findings with previously reported patient-level outcomes of trial enrollees.
Data were included on children 5–17 years old with asthma in 40 primary care practices, affiliated with managed health care plans enrolled in the Pediatric Asthma Care Patient Outcomes Research Team (PORT) randomized trial.
Primary care practices were randomly assigned to one of two care improvement arms or to usual care. Automated claims data were analyzed for 12-month periods using a repeated cross-sectional design. The primary outcome was evidence of at least one controller medication dispensed among patients with persistent asthma. Secondary outcomes included controller dispensing among all identified asthmatics, evidence of chronic controller use, and the dispensing of oral steroids. Health service utilization outcomes included numbers of ambulatory visits and hospital-based events.
The proportion of children with persistent asthma prescribed controllers increased in all study arms. No effect of the interventions on the proportion receiving controllers was detected (peer leader intervention effect 0.01, 95 percent confidence interval [CI]: −0.07, 0.08; planned care intervention effect −0.03, 95 percent CI: −0.09, 0.02). A statistical trend was seen toward an increased number of oral corticosteroid bursts dispensed in intervention practices. Significant adjusted increases in ambulatory visits of 0.08–0.10 visits per child per year were seen in the first intervention year, but only a statistical trend in these outcomes persisted into the second year of follow-up. No differences in hospital-based events were detected.
This analysis showed a slight increase in ambulatory asthma visits as a result of asthma care improvement interventions, using automated data. The absence of detectable impact on medication use at the practice level differs from the positive intervention effect observed in patient self-reported data from trial enrollees. Analysis of automated data on nonenrollees adds information about practice-level impact of care improvement strategies. Benefits of practice-level interventions may accrue disproportionately to the subgroup of trial enrollees. The effect of such interventions may be less apparent at the level of practices or health plans.
Asthma care; randomized controlled trial; chronic care model; physician behavior change
The objectives of this study were to: (1) identify modifiable factors influencing receipt of influenza vaccination among children with asthma, and (2) to evaluate the effect of heightened media attention on vaccination rates.
During November and December 2003, we interviewed parents of children with asthma about their experiences with and beliefs about influenza vaccination. We randomly selected 500 children from a study population of 2,140 children identified with asthma in a managed care organization in Massachusetts. We obtained data on influenza vaccination status from computerized medical records and determined significant factors influencing receipt of influenza vaccination.
Children were more likely to be vaccinated if their parent recalled a physician recommendation (odds ratio [OR] 2.6; 95% confidence interval [CI] 1.5, 4.5), believed the vaccine worked well (OR 2.0; 95% CI 1.4, 2.8), or expressed little worry about vaccine adverse effects (OR 1.3; 95% CI 1.0, 1.6), or if the child was younger (OR 1.1 per year of age; 95% CI 1.0, 1.2).
During the study period, there was heightened media attention about influenza illness and the vaccine. The influenza vaccination rate for children with asthma was 43% in 2003–04 compared with 27% in 2002–03. Comparison of weekly influenza vaccination rates in 2003–04 and 2002–03 suggested that the media attention was associated with the increase in vaccination rates.
Physician recommendations and parental education about influenza vaccine availability, effectiveness, and adverse effects are potentially important influences on influenza vaccination. Our findings suggest that media coverage of the risks of influenza was associated with a significant increase in vaccination rates.
To characterize and describe variability in processes of asthma care and services tailored for low–income populations in practice sites participating in Medicaid managed care (MMC).
Eighty-five practice sites affiliated with five not-for-profit organizations participating in managed Medicaid (three group-model health maintenance organizations [HMOs] and two Medicaid managed care organizations [MCOs]).
Study Design/Data Collection
We conducted a mail survey of managed care practice site informants using a conceptual model that included chronic illness care and services targeting low-income populations. The survey asked how frequently a number of processes related to asthma care occurred at the practice sites (on a scale from “never” to “always”). We report mean and standard deviations of item scores and rankings relative to other items. We used within-MCO intraclass correlations to assess how consistent responses were among practice sites in the same MCO.
Processes of care related to asthma varied greatly in how often practice sites reported doing them, with information systems and self-management support services ranking lowest. There was also significant variation in the availability of services targeting low-income populations, specifically relating to cultural diversity, communication, and enrollee empowerment. Very little of the site-to-site variation was attributable to the MCO.
Our conceptual framework provides a means of assessing the provision of chronic illness care for vulnerable populations. There is room for improvement in provision of chronic asthma care for children in managed Medicaid, particularly in the areas of self-management support and information systems. The lack of consistency within MCOs on many processes of care suggests that care may be driven more at the practice site level than the MCO level, which has implications for quality improvement efforts.
Chronic illness care; low-income populations; Medicaid managed care
To highlight the unique challenges of evaluative research on practice behavior change in the “real world” settings of contemporary managed-care organizations, using the experience of the Pediatric Asthma Care PORT (Patient Outcomes Research Team).
The Pediatric Asthma Care PORT is a five-year initiative funded by the Agency for Healthcare Research and Quality to study strategies for asthma care improvement in three managed-care plans in Chicago, Seattle, and Boston. At its core is a randomized trial of two care improvement strategies compared with usual care: (1) a targeted physician education program using practice based Peer Leaders (PL) as change agents, (2) adding to the PL intervention a “Planned Asthma Care Intervention” incorporating joint “asthma check-ups” by nurse-physician teams. During the trial, each of the participating organizations viewed asthma care improvement as an immediate priority and had their own corporate improvement programs underway.
Investigators at each health plan described the organizational and implementation challenges in conducting the PAC PORT randomized trial. These experiences were reviewed for common themes and “lessons” that might be useful to investigators planning interventional research in similar care-delivery settings.
Randomized trials in “real world” settings represent the most robust design available to test care improvement strategies. In complex, rapidly changing managed-care organizations, blinding is not feasible, corporate initiatives may complicate implementation, and the assumption that a “usual care” arm will be static is highly likely to be mistaken. Investigators must be prepared to use innovative strategies to maintain the integrity of the study design, including: continuous improvement within the intervention arms, comanagement by researchers and health plan managers of condition-related quality improvement initiatives, procedures for avoiding respondent burden in health plan enrollees, and anticipation and minimization of risks from experimental arm contamination and major organizational change. With attention to these delivery system issues, as well as the usual design features of randomized trials, we believe managed-care organizations can serve as important laboratories to test care improvement strategies.
Guideline implementation; managed-care research; childhood asthma; physician behavior change; randomized trials
This study's objective was to elicit the views of research among enrollees in an HMO. A questionnaire was mailed to 207 adult enrollees, 55% had been exposed to research and 45% had not. Ninety-four percent of respondents supported research within the HMO, and 87% thought using information from medical records for research was acceptable. Sixty-three percent thought participation in research increased patient understanding of health care. Significantly more prior research participants thought that participation in research improves care. More patients would participate if written information were provided (67%), if feedback of results was provided (72%), and if their clinician invited them (67%). Only a modest percentage (20%) of patients would participate in a randomized trial.
Patient participation; research; managed care