Potential impact on vaccination coverage levels by administering vaccines simultaneously and reducing dropout rates

Impact of a vaccination promotion intervention using motivational interview techniques on long-term vaccine coverage: the PromoVac strategy

BACKGROUND

Delayed vaccinations at 2, 4, and 6 months are associated with a higher probability of delayed age-appropriate vaccination during childhood. This study aimed to assess the effectiveness of an information session on immunization during infancy.

METHODS

An individual educational information session with motivational interview techniques for immunization of infants was conducted (experimental group) or not conducted (control group) during postpartum stay in a quasi-experimental cohort study. Immunization data were collected from the Eastern Townships Public Health registry at 3, 5, 7, 13, 19, and 24 months of age. Logistic regressions with repeated measures were performed to assess the intervention's impact. Relative risks (RR) were estimated. A multivariate model was obtained adjusted for confounding factors.

RESULTS

The experimental and control groups included 1140 and 1249 families, respectively. In per protocol analysis, a significant increase in VC of 3.2, 4.9, 7.3, 6.7, 10.6, and 5.1% was observed at 3, 5, 7, 13, 19, and 24 months. Children from experimental group had 9% more chance at a complete vaccination status between 3 and 24 months compared to children from control group (RR (95% CI): 1.09 (1.05-1.13), p < .001). Children with complete vaccination status at 3 months were more likely to have a complete vaccination status at 24 months (82.3 vs. 48.1%, RR (95% CI): 2.72 (2.28-3.24), p < .001). After adjustment, the estimated RR of the intervention's impact was 1.05 (1.02-1.07), p < .001.

CONCLUSIONS

An educational information session about immunization based on motivational interview techniques conducted during postpartum hospitalization could improve immunization during infancy.

Coverage, Timelines, and Determinants of Incomplete Immunization in Bangladesh

Immunization has become one of the major contributors to public health globally as it prevents communicable disease, particularly in children. The objective of this study was to estimate the extent of timely immunization coverage and to investigate the determinants of incomplete and untimely vaccination. Methods: The study used data from the latest Bangladesh Demographic Health Survey (BDHS) 2014. A total sample of 1631 children aged 12–23 months who had an Expanded Program on Immunization (EPI) card and immunization history were analyzed. Multivariable logistic regression models were used to determine the significant influencing factors on untimely vaccination (BCG, pentavalent vaccine/OPV, and measles) and incomplete vaccination. The results were presented in terms of adjusted odds ratio (AOR) with a 95% confidence interval and a significance level p < 0.05. Results: The proportions of children who received timely vaccinations were 24% for BCG, 46% for pentavalent 3, and 53% for measles, whereas 76%, 51%, and 36% children failed to receive the BCG, pentavalent 3, and measles vaccines, respectively, in a timely manner. The proportion of early vaccination was 3% for pentavalent 3 and 12% for measles. Several significant influencing factors including age, maternal education and working status, awareness of community clinics, socioeconomic status, and geographic variation significantly contributed to untimely and incomplete vaccination of children in Bangladesh. Conclusions: The study identified some key determinants of untimely and incomplete childhood vaccinations in the context of Bangladesh. The findings will contribute to the improvement of age-specific vaccination and support policy makers in taking the necessary control strategies with respect to delayed and early vaccination in Bangladesh.

Evaluation of potentially achievable vaccination coverage of the second dose of measles containing vaccine with simultaneous administration and risk factors for missed opportunities among children in Zhejiang province, east China

OBJECTIVES

This study aimed to evaluate the potential achievable coverage of the second dose of measles containing vaccine (MCV2) when the protocol of simultaneous administration of childhood vaccines was fully implemented. Risk factors for missed opportunity (MO) for simultaneous administration of MCV2 were also investigated.

METHODS

Children born from 1 January 2005 to 31 December 2014 and registered in Zhejiang provincial immunization information system were enrolled in this study. The MO of simultaneous administration of MCV2, the actual age-appropriate coverage (AAC) of MCV2 and the potentially achievable coverage (PAC) of MCV2 were evaluated and compared across different birth cohorts, by different socio-demographic variables. For the 2014 birth cohort, logistic regression model was used to detect the risk factors of MOs, from both socio-demographic and vaccination service providing aspects.

RESULTS

Compared to the AAC, the PAC of MCV2 increased significantly from 2005 birth cohort to 2014 birth cohort (p<0.001), with a median of 12.7 percentage points. Higher birth order of children, resident children, higher maternal education background, higher socio-economic development level of resident areas, less frequent vaccination service, and shorter vaccination service time were significant risk factors of MO for simultaneous administration of MCV2, with all p-value < 0.05.

CONCLUSION

The findings in this study suggest that fully utilization of all opportunities for simultaneous administration of all age-eligible vaccine doses at the same vaccination visit is critical for achieving the coverage target of 95% for MCV2. Future interventions focusing on the group with risk factors observed could substantially eliminate MOs for simultaneous administration of MCV2, further to improve the coverage of fully immunization of MCV, and finally achieve the goal of eliminating measles.

Missed opportunities for simultaneous administration of the fourth dose of DTaP among children in the United States

BACKGROUND

Simultaneous administration of all age-appropriate doses of vaccines is an effective strategy for raising vaccination coverage. Vaccination coverage for ≥4 dose of DTaP (diphtheria, tetanus toxoids, and acellular pertussis vaccine) among children 19-35months in the United States has not reached the Healthy People 2020 target of 90%. Risk factors for missed opportunities for simultaneous administration of the fourth dose of DTaP have not been investigated.

METHODS

A missed opportunity for simultaneous administration of the fourth dose of DTaP is defined as the failure to administer an age-eligible fourth dose of DTaP, and during the same age-eligible period for the fourth dose of DTaP other recommended and age-appropriate doses of vaccines are given to children. This study used 2001-2014 National Immunization Survey data to describe the trend in missed opportunities for simultaneous administration of the fourth dose of DTaP from 2001 through 2014, assess the prevalence of children who missed opportunities for simultaneous administration of the fourth dose of DTaP by selected factors, and recognize significant risk factors for missed opportunities for simultaneous administration of the fourth dose of DTaP.

RESULTS

From 2001 to 2014, the prevalence of missed opportunities for simultaneous administration of the fourth dose of DTaP among children 19-35months in the United States ranged from 5.7% to 9.0%; across 13 factors considered, the prevalence of missed opportunities varied from 3.3% to 22.9%. Children who were late in receiving the first to third dose of DTaP had significantly higher prevalence of missed opportunities for simultaneous administration of the fourth dose of DTaP than children who received these doses on-time, with adjusted prevalence ratios for late vs. on-time of 1.7, 1.6, and 3.2, and all P-value<0.01.

CONCLUSIONS

Improving on-time vaccination of the third dose of DTaP could substantially reduce missed opportunities for simultaneous administration of the fourth dose of DTaP.

Vaccine coverage and adherence to EPI schedules in eight resource poor settings in the MAL-ED cohort study

BACKGROUND

Launched in 1974, the Expanded Program on Immunization (EPI) is estimated to prevent two-three million deaths annually from polio, diphtheria, tuberculosis, pertussis, measles, and tetanus. Additional lives could be saved through better understanding what influences adherence to the EPI schedule in specific settings.

METHODS

The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study followed cohorts in eight sites in South Asia, Africa, and South America and monitored vaccine receipt over the first two years of life for the children enrolled in the study. Vaccination histories were obtained monthly from vaccination cards, local clinic records and/or caregiver reports. Vaccination histories were compared against the prescribed EPI schedules for each country, and coverage rates were examined in relation to the timing of vaccination. The influence of socioeconomic factors on vaccine timing and coverage was also considered.

RESULTS

Coverage rates for EPI vaccines varied between sites and by type of vaccine; overall, coverage was highest in the Nepal and Bangladesh sites and lowest in the Tanzania and Brazil sites. Bacillus Calmette-Guérin coverage was high across all sites, 87-100%, whereas measles vaccination rates ranged widely, 73-100%. Significant delays between the scheduled administration age and actual vaccination date were present in all sites, especially for measles vaccine where less than 40% were administered on schedule. A range of socioeconomic factors were significantly associated with vaccination status in study children but these results were largely site-specific.

CONCLUSIONS

Our findings highlight the need to improve measles vaccination rates and reduce delayed vaccination to achieve EPI targets related to the establishment of herd immunity and reduction in disease transmission.

Coverage & missed opportunity for Japanese encephalitis vaccine, Gorakhpur division, Uttar Pradesh, India, 2015: Implications for Japanese encephalitis control

BACKGROUND & OBJECTIVES

Japanese encephalitis (JE) is an important aetiology of acute encephalitis syndrome in Gorakhpur division, Uttar Pradesh, India. Two doses of JE vaccine ( first during 9-12 months and second during 16-24 months of age) are administered under the Universal Immunization Programme. We conducted surveys to estimate the coverage of JE vaccine and magnitude of missed opportunity for vaccination (MoV) for JE in Gorakhpur division.

METHODS

To estimate the JE vaccine coverage, cluster surveys were conducted in four districts of Gorakhpur division by selecting 30 clusters by probability proportional to size method in each district, seven children aged 25-36 months were selected from each cluster and their mothers were interviewed about JE vaccination. To estimate the magnitude of MoV, exit surveys were conducted in vaccination clinics in selected health facilities, mothers were interviewed about the vaccination status of their children and vaccines administered to the child on the day of interview.

RESULTS

A total of 840 children were surveyed, 210 from each district. The coverages of one and two doses of JE vaccine in Gorakhpur division were 75 per cent [95% confidence interval (CI): 71.0-78.9] and 42.3 per cent (95% CI: 37.8-46.8), respectively. Facility-based exit survey indicated that 32.7 per cent of the eligible children missed JE vaccine.

INTERPRETATION & CONCLUSIONS

The survey results showed that three of the four children aged 25-36 months in Gorakhpur division had received at least one dose of JE vaccine. The coverage of second dose of JE vaccine, however, was low. Failure to administer vaccination simultaneously was the most common reason for MoV for JE vaccine. Training vaccinators about correct vaccination schedule and removing their misconception about administering vaccines simultaneously would substantially improve JE vaccine coverage in Gorakhpur.

Evaluation of potentially achievable vaccination coverage with simultaneous administration of vaccines among children in the United States

BACKGROUND

Routine administration of all age-appropriate doses of vaccines during the same visit is recommended for children by the National Vaccine Advisory Committee (NVAC) and the Advisory Committee on Immunization Practices (ACIP).

METHODS

Evaluate the potentially achievable vaccination coverage for ≥4 doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (4+DTaP), ≥4 doses of pneumococcal conjugate vaccine (4+PCV), and the full series of Haemophilus influenzae type b vaccine (Hib-FS) with simultaneous administration of all recommended childhood vaccines. Compare the potentially achievable vaccination coverage to the reported vaccination coverage for calendar years 2001 through 2013; by state in the United States and by selected socio-demographic factors in 2013. The potentially achievable vaccination coverage was defined as the coverage possible for the recommended 4+DTaP, 4+PCV, and Hib-FS if missed opportunities for simultaneous administration of all age-appropriate doses of vaccines for children had been eliminated.

RESULTS

Compared to the reported vaccination coverage, the potentially achievable vaccination coverage for 4+DTaP, 4+PCV, and Hib-FS could have increased significantly (P<0.001), the vaccination coverage would have achieved the 90% target of Healthy People 2020 for the three vaccines beginning in 2005, 2008, and 2011 respectively. In 2013, the potentially achievable vaccination coverage increased significantly across all selected socio-demographic factors, potentially achievable vaccination coverage would have reached the 90% target for more than 51% of the states in the United States.

CONCLUSIONS

The findings in this study suggest that fully utilization of all opportunities for simultaneous administration of all age-eligible childhood doses of vaccines during the same vaccination visit is a critical strategy for achieving the vaccination coverage target of Healthy People 2020. Encouraging providers to deliver all recommended vaccines that are due at each visit by implementing client reminder and recall systems might decrease missed opportunities for simultaneous administration of childhood vaccines.

Analysis of safety data in children after receiving two doses of ProQuad® (MMRV)

BACKGROUND

In randomized clinical studies, over 11,800 children, 12 months to 6 years of age, were administered ProQuad(®), a combination measles, mumps, rubella, and varicella vaccine (MMRV). This paper describes the safety following a 2-dose regimen of MMRV administered to children in the second year of life.

METHODS

Safety data from five clinical studies were combined for all children who were scheduled to receive two doses of MMRV ∼3-6 months apart. All vaccinated children were followed for safety following each dose of MMRV.

RESULTS

Of 3112 children who received a first dose of MMRV, 2780 (89.3%) received a second dose of MMRV. Overall, 70.5% and 57.7% of children reported ≥1 adverse experiences following first and second doses of MMRV, respectively. Injection-site redness was statistically significantly higher postdose 2 than postdose 1, while injection-site pain/tenderness was statistically significantly higher postdose 1 compared to postdose 2. Rashes were statistically significantly lower postdose 2 compared to postdose 1. Ten febrile seizures (8 postdose 1, 2 postdose 2) were reported following MMRV vaccination. The incidence of febrile seizures postdose 1 of MMRV was 0.26% (8/3019) compared to 0.07% (2/2695) postdose 2 of MMRV.

CONCLUSIONS

Administration of two doses of MMRV has an acceptable safety profile in children 12 to 23 months of age. There is a small increase in the risk of febrile seizures following the first dose of MMRV as compared to the component vaccines, but the risk for any individual child is relatively low.

Improving immunization rates of underserved children: a historical study of 10 health departments

BACKGROUND

Despite high immunization rates, hundreds of thousands of poor and underserved children continue to lack their necessary immunizations and are at risk of acquiring a vaccine-preventable disease. Local Health Departments (LHDs) and public health clinicians figure prominently in efforts to address this problem.

METHODS

This exploratory research compared ten (10) North Carolina LHDs with respect to immunization delivery factors. The study sample was identified based on urban designation as well as county demographic and socio-economic indicators that identified predicted "pockets" of underimmunization. Survey instruments were used to identify specific LHD immunization delivery factors.

RESULTS

It was found that hours of operation, appointment policies, use and type of tracking systems, and wait times influence a health department's ability to immunize underserved children. This exploratory research is of particular importance, because it suggests that the implementation of specific policy interventions may reduce the morbidity and mortality related to vaccine-preventable diseases in poor and underserved children. This research also highlights the significance of the nurses' role in the policy making process in this important area of community health assurance.

CONCLUSION

To improve childhood immunization rates, policy-makers should encourage adequate and appropriate funding for LHDs to adopt service delivery factors that are associated with higher-performing local health departments. LHDs should study the population they serve to further refine service delivery factors to meet the population's needs.

Timing of hepatitis B vaccination and impact of non-simultaneous vaccination with DTP vaccine following introduction of a hepatitis B birth dose in the Philippines

Timely administration of hepatitis B vaccine beginning at birth prevents up to 95 per cent of perinatally acquired hepatitis B virus infections in infants of infected mothers. The Philippines changed its national HepB schedule in 2007 to include a dose at birth. We evaluated vaccination schedule change by reviewing infant records at selected health facilities to measure completeness and timeliness of HepB administration and frequency of recommended, simultaneous vaccination with diphtheria-tetanus-pertussis (DTP) vaccine. Of 1431 sampled infants, 1106 (77 per cent) completed the HepB series and 10 per cent followed the national schedule. The proportion with timely vaccination declined with successive doses: HepB1 (71 per cent), HepB2 (47 per cent), and HepB3 (26 per cent). Twentysix per cent received HepB2 simultaneously with DTP1 and 34 per cent received HepB3 simultaneously with DTP3. If HepB and DTP vaccination were given simultaneously,10 per cent more infants could have received all HepB doses. Program implementers should monitor vaccination timeliness and increase simultaneous administration to improve vaccination coverage and decrease disease incidence.

Immunogenicity and safety of two tetravalent (measles, mumps, rubella, varicella) vaccines coadministered with hepatitis a and pneumococcal conjugate vaccines to children twelve to fourteen months of age

BACKGROUND

This study compared single-dose tetravalent measles, mumps, rubella, varicella vaccine, Priorix-Tetra, stored refrigerated (GSK+4C) or frozen (GSK-20C), with ProQuad (Merck-20C), when coadministered with hepatitis A vaccine (HAV) and 7-valent pneumococcal conjugate vaccine (PCV7).

METHODS

Multicenter, observer-blind phase 2 study in 1783 healthy 12-14 month olds randomized to: GSK+4C (n = 705), GSK-20C (n = 689) or Merck-20C (n = 389), administered concomitantly with HAV (Havrix) and PCV7 (Prevnar). Seroresponse rates and antibody geometric mean concentrations/titers were determined from enzyme-linked immunosorbent assay and neutralization assays. Reactogenicity and safety were assessed.

RESULTS

Seroresponse rates (day 42) were >97% for measles and rubella viruses and >92% for mumps virus, in all groups. Noninferiority of both GSK+4C and GSK-20C vaccines versus Merck-20C was demonstrated for seroresponse rates to measles, mumps and rubella viruses (lower 97.5% confidence interval above -5%, -10% and -5%, respectively). For varicella-zoster virus, seroresponse rates were 57.1%, 69.8% and 86.7% in the GSK+4C, GSK-20C and Merck-20C groups, respectively. Noninferiority was not shown for either GSK vaccine (lower 97.5% confidence intervals <-15%). Geometric mean concentration ratios for anti-varicella-zoster virus demonstrated noninferiority (lower 97.5% confidence interval ≥ 0.5) versus Merck-20C for GSK-20C only. Geometric mean concentration ratios for antibodies to HAV and to PCV7 pneumococcal serotypes also met criteria for noninferiority for both GSK groups compared with Merck-20C. GSK vaccine safety was observed comparable to Merck-20C. Localized but not generalized measles/rubella-like rash and grade 3 fever was reported slightly more frequently with GSK vaccines, but antipyretic use was similar. The incidence of subjects experiencing at least 1 serious adverse event was 2.0%, 2.9% and 1.8% in the GSK+4C, GSK-20C and Merck-20C groups, respectively.

CONCLUSIONS

Noninferiority of both GSK measles, mumps, rubella, varicella vaccines versus Merck-20C was demonstrated for responses to measles, mumps and rubella viruses but was not fully demonstrated for varicella-zoster virus. The vaccines showed acceptable reactogenicity/safety when coadministered with HAV and PCV7.

Feasibility and impact of providing feedback to vaccinating medical clinics: evaluating a public health intervention

Background

Vaccine coverage (VC) at a given age is a widely-used indicator for measuring the performance of vaccination programs. However, there is increasing data suggesting that measuring delays in administering vaccines complements the measure of VC. Providing feedback to vaccinators is recognized as an effective strategy for improving vaccine coverage, but its implementation has not been widely documented in Canada. The objective of this study was to evaluate the feasibility of providing personalized feedback to vaccinators and its impact on vaccination delays (VD).

Methods

In April and May 2008, a one-hour personalized feedback session was provided to health professionals in vaccinating medical clinics in the Quebec City region. VD for vaccines administered at two and twelve months of age were presented. Data from the regional vaccination registry were analysed for participating clinics. Two 12-month periods before and after the intervention were compared, namely from April 1^st, 2007 to March 31^st, 2008 and from June 1^st, 2008 to May 31^st, 2009.

Results

Ten medical clinics out of the twelve approached (83%), representing more than 2500 vaccinated children, participated in the project. Preparing and conducting the feedback involved 20 hours of work and expenses of $1000 per clinic. Based on a delay of one month, 94% of first doses of DTaP-Polio-Hib and 77% of meningococcal vaccine doses respected the vaccination schedule both before and after the intervention. Following the feedback, respect of the vaccination schedule increased for vaccines planned at 12 months for the four clinics that had modified their vaccination practices related to multiple injections (depending on the clinic, VD decreased by 24.4%, 32.0%, 40.2% and 44.6% respectively, p < 0.001 for all comparisons).

Conclusions

The present study shows that it is feasible to provide personalized feedback to vaccinating clinics. While it may have encouraged positive changes in practice concerning multiple injections, this intervention on its own did not impact vaccination delays of the clinics visited. It is possible that feedback integrated into other types of effective interventions and sustained over time may have more impact on VD.

Trends in early childhood vaccination coverage: progress towards US Healthy People 2010 goals

OBJECTIVES

To evaluate trends in national vaccination coverage from 2000 to 2007 among children aged 19-35 months for at least four doses of diphtheria-tetanus-pertussis vaccine (4+DTaP), three doses of poliovirus vaccine (3+Polio), one dose of measles-mumps-rubella vaccine (1+MMR), three doses of Haemophilus influenzae type b vaccine (3+Hib), three doses of hepatitis B vaccine (3+HepB), one dose of Varicella vaccine (1+Var), and the standard vaccine series of these six vaccines (4:3:1:3:3:1). To predict vaccination coverage levels in 2008-2010 for those vaccines that have not yet reached the Healthy People 2010 coverage targets of 90% for individual vaccines and 80% for the vaccine series.

METHODS

Data were analyzed for 167,086 children aged 19-35 months in the 2000-2007 National Immunization Survey. Vaccination coverage trends were analyzed with weighted least squares linear regression models. Nonlinear Weibull and logarithmic regression models were fitted to these past results, and extrapolation was used to predict vaccination coverage levels for 4+DTaP, 1+Var, and the 4:3:1:3:3:1 series from 2008 to 2010.

RESULTS

From 2000 to 2007, observed vaccination coverage increased significantly for four of the six vaccines and the standard vaccine series, and reached the 90% target for 3+Polio, 1+MMR, 3+Hib, and 3+HepB. Increases in coverage were not significant for 1+MMR and 3+Hib; however, coverage for these vaccines was consistently>90% throughout the study period. Both Weibull and logarithmic regression models predicted that coverage with 1+Var and the 4:3:1:3:3:1 series will surpass the 2010 target by 2008, while coverage with 4+DTaP will fall short of the target at 86% in 2010.

CONCLUSIONS

The United States is well on the way toward reaching most of the Healthy People 2010 objectives for early childhood vaccination coverage. Enhanced efforts are needed to ensure that these trends continue, and to increase coverage with 4+DTaP.

When and why children fall behind with vaccinations: missed visits and missed opportunities at milestone ages

OBJECTIVE

Little is known about when-and why-children fall behind in their recommended vaccinations. Vaccination status throughout the first 2 years of life was examined to identify vulnerable transition periods that account for attrition and to determine whether children fell behind because they missed vaccination visits or because of missed opportunities for simultaneous vaccination.

METHODS

Vaccination histories for 27,083 children aged 24-35 months in the 2006-2007 National Immunization Survey were analyzed to determine the vaccination status at each age in days, focusing on the milestone ages of 3, 5, 7, 16, 19, and 24 months. Also assessed were the percentage of children who fell behind between milestones and the percentage who did so due to the lack of a vaccination visit compared to a missed opportunity for simultaneous vaccination.

RESULTS

The percentage of children who fell behind from one milestone age to the next ranged from 9% during the interval from age 16 months to 19 months to 20% during the interval from age 7 months to age 16 months. Missed vaccination visits accounted for most attrition during the intervals from age 3 months to age 5 months, age 5 months to age 7 months, and age 16 months to age 19 months, while missed opportunities for simultaneous vaccination accounted for >90% of the children who fell behind during the interval from age 7 months to age 16 months.

CONCLUSIONS

Missed vaccination visits and missed opportunities for simultaneous vaccinations both must be addressed to reduce the number of children falling behind in their vaccinations. With one in five children falling behind during the interval from age 7 months to age 16 months--mostly as a result of missed opportunities for simultaneous vaccination--providers should focus on this time interval to deliver all of the recommended vaccinations that are due.

Use of combination vaccines is associated with improved coverage rates

BACKGROUND

The number of shots represented by the routine childhood immunization schedule poses a logistical challenge for providers and a potential deterrent for parents. By reducing the number of injections, use of combination vaccines could lead to fewer deferred doses and improved coverage rates.

OBJECTIVE

To determine the effect of combination vaccines on coverage rates.

METHODS

This was a retrospective study of administrative claims data from the Georgia Department of Community Health Medicaid program conducted from January through September of 2003. Coverage rates were compared between children who received at least 1 dose of HepB/Hib (COMVAX) or DTaP/HepB/IPV (PEDIARIX) (the combination cohort) and children who received no doses of either combination (the reference cohort). Infants with fewer than 4 vaccination visits were excluded from the analysis. Multivariate logistic regression was performed on the whole study population to assess the effect of combination vaccines while controlling for potential confounders. Hepatitis B and pneumococcal conjugate vaccine coverage rates were not included as outcomes.

RESULTS

The study population consisted of 18,821 infants, 16,007 in the combination cohort and 2814 in the reference cohort. Unadjusted coverage rates for DTaP, IPV and the 4 DTaP:3 IPV:1 MMR, 4 DTaP: 3 IPV: 1 MMR: 3 Hib: 1 varicella, and 3 DTaP:3 IPV: 3 Hib series were higher in the combination cohort. Receipt of at least 1 dose of a combination vaccine was independently associated with increased coverage for each of these vaccines and vaccine series when controlling for gender, birth quarter, race, rural versus urban residence and historical provider immunization quality.

CONCLUSIONS

Use of combination vaccines in this Medicaid population was associated with improved coverage rates. Additional studies are warranted, including those examining private sector populations and outcomes such as timeliness and cost.

Assessment of delay in age-appropriate vaccination using survival analysis

Assessment of delay in age-appropriate vaccination provides more information about timeliness of vaccination than up-to-date vaccination coverage. The authors applied survival analysis methods to data from a vaccination coverage survey among children aged 13-59 months conducted in Argentina in 2002. By age 19 months, 43% of children (95% confidence interval (CI): 40, 46) were vaccinated with the fourth dose of diphtheria, tetanus, and pertussis (DTP4). By age 13 months, 55% of children (95% CI: 52, 57) were vaccinated with measles-containing vaccine. By age 7 months, 33% of children (95% CI: 27, 40) were vaccinated with the third dose of hepatitis B. Compared with firstborn children, third children were more likely to be delayed for DTP4 (relative risk (RR) = 1.41, 95% CI: 1.22, 1.62), measles-containing vaccine (RR = 1.54, 95% CI: 1.32, 1.78), and the third dose of hepatitis B (RR = 1.31, 95% CI: 1.03, 1.67). Children whose caregivers had completed secondary school were less likely to be delayed for DTP4 (RR = 0.68, 95% CI: 0.52, 0.90) compared with those whose caregivers had not completed primary school. Survival analysis methods were helpful in measuring vaccine uptake and should be considered in future surveys when assessing delay in age-appropriate vaccination.

Do too many shots due lead to missed vaccination opportunities? Does it matter?

BACKGROUND

Missed childhood vaccination opportunities have been generally described, yet not since the immunization schedule's recent rapid expansion. Little is known about the relationship between the number of vaccine doses due and whether all scheduled doses are administered, and the effect of dose deferral on immunization coverage.

METHODS

32 private pediatrics centers reviewed medical records covering the first 2 years of life for 858 patients. For each visit during ages 2-8 months, we determined the numbers of vaccine doses due versus administered. Logistic regression was used to assess the effect of dose deferral on immunization coverage at ages 1 and 2 years.

RESULTS

Of 2224 visits during ages 2-8 months at which > or =1 dose was administered, > or =1 due dose was deferred at 26%, 34%, and 48% of the visits at which < or =3, 4, and 5 doses were due, respectively. Absence of a deferred dose visit predicted increased coverage at age 1 (adjusted odds ratio: 2.4, 95% confidence interval: 1.8-3.2) and 2 years (2.1, 1.4-3.0).

CONCLUSIONS

Administering some but not all vaccine doses at visits during ages 2-8 months impairs immunization coverage through age 2 years.

Assessing the impact of wastage on pediatric vaccine immunization formulary costs using a vaccine selection algorithm

Pediatric immunization is an important factor in providing protection against numerous common preventable diseases. The success of the pharmaceutical industry in developing new pediatric vaccines has resulted in a crowded recommended immunization schedule requiring several clinic visits over the first 12 years of life. Operations research models have been developed and used to make economically sound procurement choices from among a growing number of competing vaccine products. One factor that has not been incorporated into such models is the economic impact of wastage on such decisions. This paper reports results obtained from a vaccine selection algorithm that incorporates vaccine wastage data. The lowest overall cost formularies comparing no wastage costs with wastage costs are presented. A sensitivity analysis of the vaccine formulary with respect to the wastage rates associated with each available vaccine is provided. The maximum permissible wastage rate for each vaccine is determined for which the vaccine earns a place in the lowest overall cost formulary. This research provides health maintenance organizations and healthcare providers information that can be used to gain a better understanding of wastage and its impact on pediatric formulary costs.

One for all: newer combination vaccines in practice

As new combination vaccines are approved, practices must consider whether to switch. The decision is likely to be complex, involving everything from re-education of staff to recalculating the bottom line. At some point, however, change will be inevitable, driven principally by the need to add new vaccines to the schedule. In fall 2004, practitioners will be adding two doses of inactivated influenza vaccine to the infant schedule. More communities will be adding two doses of hepatitis A vaccine, which may become routine for all children at some point. We can hope as well for a meningococcal conjugate vaccine series, which, like Hib and PCV-7, would be administered by an infant's first birthday. In addition, there's the pentavalent bovine reassortant rotavirus vaccine (Rotateq) which, although given orally, will further crowd the schedule. The sooner we become comfortable with combination vaccines, the better.

Early continuity of care and immunization coverage

OBJECTIVE

We examined the relationship between early and exclusive continuity of care at the initial source of care and immunization coverage.

METHODS

We used a cohort study design with 641 randomly selected children initiating care before 3 months and making 2 or more visits to an inner-city practice network. We used 2 complementary data sources: medical records and the New York City Department of Health Citywide Immunization Registry. Immunization measures were cumulative age appropriate and up-to-date at 18 months (UTD18).

RESULTS

There was a gradual attrition from the initial source of care. By 18 months, less than half the children (46%) remained in care. Regardless of continuity, nearly half (42%) had used other immunization providers. The initial source of care contributed most immunizations (89%-94%); however, across all levels of continuity, children who also used other providers had higher immunization rates. We found a threshold effect of continuity beginning at 12 months: children in care from 12 to 14 months were 17.5 times more likely to be UTD18 than those in care less than 6 months. Each additional period in care increased the time remaining current with immunizations. Among children UTD18, 88% were in care at 11 months compared with 38% among those not UTD18, a 50% difference.

CONCLUSIONS

Continuity of care at the initial source of care had a significant and lasting impact on immunization coverage, even if not used exclusively. Interventions promoting continued use of the medical home over the first 2 years of life may help improve immunization coverage.

Clinician satisfaction with vaccination visits and the role of multiple injections, results from the COVISE Study (Combination Vaccines Impact on Satisfaction and Epidemiology)

Because little is known about clinician satisfaction with infant vaccination visits, we measured satistaction and the effects of the number of injections on satisfaction. Clinicians from 35 pediatric centers self-administered a questionnaire using visual analog scales augmented by a Likert scale. All 95 pediatricians and 137 nonphysician vaccinators responded. In both populations, increased injections predicted decreased overall satisfaction, and decreased satisfaction with obtaining consent, time to prepare/administer, getting upset during administration, and time to update records (each p<0.01). Satisfaction decreased markedly, on each measure, at 4-injection visits, 5-injection visits, or both.

[Why are some children incompletely vaccinated at the age of 2?]

OBJECTIVE

A survey was conducted in the Province of Quebec to document the factors associated with an incomplete immunization status among 2-year-old children.

METHODS

Parents of 430 completely and 266 partially vaccinated children selected from the computerized vaccination register agreed to participate.

RESULTS

The non-simultaneous administration of the 2nd MMR and 4th DPT-P-Hib at 18 months of age was responsible for 46% of incompleteness. The following characteristics were significantly associated with an incomplete immunization status: being a single parent, > or = 2 children in the family, an older age at first immunization (> or = 3 months), parent's preference for postponing the second vaccine when two injections are scheduled for the same visit, perception of lack of information about vaccination, and disagreement with immunization recommendations.

CONCLUSION

One of the key points of this study is the impact of the non-simultaneous administration of the two vaccines at 18 months. Factors such as being a single parent and older age at first immunization might be used to design an early intervention for children who are most likely to be incompletely immunized. Even if parents are favourable towards immunization, they need to be well informed about the associated risks and benefits.

The effect of education, feedback, and provider prompts on the rate of missed vaccine opportunities in a community health center

The purpose of this study was to determine whether education, feedback, and provider prompts decrease the rate of missed vaccine opportunities; and the reasons for missed opportunities in the post-intervention group. A nonrandomized, before and after study to evaluate the effect of education, feedback, and provider prompts on missed opportunities was conducted in an inner-city community health center with a predominantly hispanic population. Vaccine opportunities were defined as visits of children 36 months or younger who were vaccination-eligible by ACIP guidelines. Consecutive sampling was used to identify two groups of children with vaccine opportunities: pre- and post-intervention. Feedback was given to vaccine providers on the frequency of missed opportunities in the pre-intervention group. The ACIP recommended vaccine schedule and true vaccine contraindications were reviewed. Nursing personnel were taught to identify and tag charts of children with vaccine opportunities. Physicians were asked to record vaccination status and the reason any vaccination was deferred. Missed opportunities decreased significantly, from 49% (173/352) to 13% (45/344), after the interventions (p < 0.001). The reasons for the 45 missed opportunities in the post-intervention sample were parent refusal (15.6%), moderate or severe illness (15.6%), and incorrect documentation as "up-to-date" (13.3%). In 28.9% there was a missed opportunity for simultaneous immunization. No reasons were documented for the remaining missed opportunity visits (26.6%). The interventions, which emphasized improving provider knowledge of vaccinations and screening vaccine status at each visit, effectively decreased missed opportunities.

Using Monte Carlo simulation to determine combination vaccine price distributions for childhood diseases

The Recommended Childhood Immunization Schedule provides guidelines that allow pediatricians to administer childhood vaccines in an efficient and effective manner. Research by vaccine manufacturers has resulted in the development of new vaccines that protect against a growing number of diseases. This has created a dilemma for how to insert such new vaccines into an already crowded immunization schedule, and prompted vaccine manufacturers to develop vaccine products that combine several individual vaccines into a single injection. Such combination vaccines permit new vaccines to be inserted into the immunization schedule without requiring children to be exposed to an unacceptable number of injections during a single clinic visit. Given this advantage, combination vaccines merit an economic premium. The purpose of this paper is to describe how Monte Carlo simulation can be used to assess and quantify this premium by studying four combination vaccines that may become available for distribution within the United States. Each combination vaccine is added to twelve licensed vaccine products for six childhood diseases (diphtheria, tetanus, pertussis, haemophilus influenzae type B, hepatitis B, and polio). Monte Carlo simulation with an integer programming model is used to determine the (maximal) inclusion price distribution of four combination vaccines, by randomizing the cost of an injection. The results of this study suggest that combination vaccines warrant price premiums based on the cost assigned to administering an injection, and that further developments and innovations in this area by vaccine manufacturers may provide significant economic and societal benefits.

Combination vaccines: practical considerations for public health and private practice

BACKGROUND

Although the current immunization schedule for children requires as many as four or five injections at a single visit, both parents and health care providers hesitate to administer more than two or three simultaneous injections. Therefore new combination vaccines that include multiple unrelated antigens are needed.

METHODS

Individuals from the Immunization Division of the Colorado State Department of Health and pediatricians in private practice in Denver, CO, were interviewed and asked about incorporating new combination vaccines into their practice.

RESULTS

At a state health department level the transition to combination vaccines will likely require reprioritizing of public health resources. In addition state health officials are important information resources for public and private providers, as well as for the community. At the level of the private provider combination vaccines hold promise for simplifying the immunization schedule, but successful implementation will require education and guidance on how best to integrate the new combination into practice.

CONCLUSIONS

Combination vaccines are the immediate solution to the addition of new childhood vaccines and will alleviate the concern of parents and physicians regarding the trauma related to multiple injections at a single visit.

Provider characteristics and behaviors as predictors of immunization coverage

BACKGROUND

Most studies of immunization behaviors measure adherence to standard immunization practices, relying on surveys without linking reported behaviors to objectively measured immunization rates. This study attempts to close that gap.

METHODS

In 1997, pediatric, family, and general providers in Pennsylvania serving children aged < 36 months (N = 251) completed immunization behavior surveys. We linked these responses to patient chart audits for practice-level immunization rates.

RESULTS

Immunization rates for our sample fell short of national goals (average up-to-date immunization status at 12 months = 69%). They were significantly higher for pediatricians than for family/general practitioners (78% vs 58%, p < 0.001) and for practices treating > or = 100 children in the past 30 working days than for those treating < 100 children (77% vs 62%, p < 0.001). Behaviors with significant associations to higher immunization coverage were: (1) appropriately giving diphtheria, tetanus toxoids, and pertussis immunization under false contraindications versus withholding it (73% vs 66%, p < 0.05); (2) willingness to give at least four injections at one visit versus fewer injections (74% vs 65%, p < 0.01); and (3) holding immunization in-service training versus no training (71% vs 65%, p < 0.05). However, multivariate analysis showed that only provider specialty remained a significant predictor of coverage.

CONCLUSIONS

Pediatricians have higher coverage rates than family/general practitioners. Although pediatricians see more children, the number of immunization-delayed children at 12 months is approximately the same for both provider groups. Therefore, efforts to improve coverage should continue to be directed toward both groups.

Economic value to parents of reducing the pain and emotional distress of childhood vaccine injections

BACKGROUND

One reason that recommended childhood immunizations due at child health visits are deferred is to avoid the pain and emotional distress associated with the increasing number of injections required. This deferral leads to additional visits and costs and reduced immunoprotection against vaccine-preventable illnesses. To assess the economic value of combination vaccines that address this problem, we surveyed parents to determine the amount they would be willing to pay to avoid the pain and emotional distress experienced by their infants from injections.

METHODS

A self-administered questionnaire was completed within 24 h of the vaccinations by 294 parents of children ages 11/2 to 7 months receiving vaccine injections at 26 outpatient child health centers. The willingness-to-pay (WTP) method was used to estimate the intangible cost of the pain and emotional distress of the 1 to 4 injections their child had received. Parents were asked how much of their own money they would have paid to avoid these injections, without any compromise in the safety and efficacy of the vaccinations.

RESULTS

Wide variations in WTP amounts were observed, ranging from median values of $10 to $25 and average values of $57.06 to $79.28 to avoid the pain and emotional distress associated with eliminating all injections at visits in which one to four injections were administered. Parents placed greater value on reductions that avoided all injections than on reductions that avoided only some injections. Overall the median cost per injection avoided was $8.14, and the mean was $30.28.

CONCLUSIONS

Parents have strong preferences for limiting vaccine injections. The economic cost of the pain and distress associated with such injections, reflected in the amounts they report they would be willing to pay to avoid them, represents a substantial component of the cost of disease control through immunization.

Immunization recall: effectiveness and barriers to success in an urban teaching clinic

OBJECTIVE

To examine effectiveness of immunization recall in an urban pediatric teaching clinic and to identify barriers to recall effectiveness.

DESIGN

Randomized, controlled trial. Children aged 5 to 17 months who were not up to date (UTD) with recommended immunizations were identified and assigned to intervention (n = 294) or control groups (n = 309). The intervention consisted of a mailed postcard and up to 4 telephone calls. Two months after intervention, UTD status, visit, and probable missed opportunity rates were assessed.

RESULTS

Of the intervention group, 30% could not be reached. In 12-month-old children in the intervention group compared with those in the control group, there was a trend toward higher UTD rates (51% vs 39%, P =.07) and a higher proportion of UTD children receiving immunizations as opposed to getting more complete documentation (25% vs 10%, P =.005). Similar differences between intervention and control children were not seen in the 7-month and 19-month age categories. More children in the intervention group had a health maintenance visit (17% vs 11%, P =.03). Of children in the intervention group who were seen when not UTD, 17 of 24 (71%) of those seen for an illness visit and 5 of 24 (21%) of those seen for health maintenance probably had missed opportunities to be immunized.

CONCLUSIONS

Recall efforts were partially successful but were undermined by inability to reach the clinic population, poor documentation of immunizations, and missed opportunities.

Vaccination visits in early childhood: just one more visit to be fully vaccinated

BACKGROUND

This study characterizes the healthcare visits at which children receive vaccinations, including the number of these visits and the number of vaccinations that are administered.

METHODS

The 1999 National Immunization Survey (NIS) is a nationally representative sample of children aged 19 to 35 months, verified by provider records, that is conducted to obtain estimates of vaccination coverage rates. We describe the number of healthcare visits in which one or more vaccinations were given, the number of vaccinations given at these visits, and the number of visits and vaccinations needed for an underimmunized child to complete the recommended vaccination series.

RESULTS

Of the children who did not receive all doses of the recommended vaccinations (4:3:1:3:3 vaccination series), three fourths had four or more immunization visits. Vaccination coverage increased as the number of visits increased, and children who had completed the series were more likely to receive multiple vaccinations than those who had not. Most children (70.7%) received a maximum of four vaccinations in any immunization visit. The majority of children (73.5%) who had not completed the 4:3:1:3:3 vaccination series needed only a single visit to complete the series. The majority (61.7%) of children who needed only one visit also needed only one additional vaccination.

CONCLUSIONS

While estimated national coverage for all recommended vaccinations is considerably below the Healthy People 2000 and Healthy People 2010 goal of 90%, achieving this goal is in essence just one visit away. If all children who needed one more visit were to receive that final visit, the national coverage among children 19 to 35 months for all recommended vaccinations would be 93%.

Undervaccinated African-American preschoolers: a case of missed opportunities

OBJECTIVE

To identify factors associated with undervaccination of African-American preschoolers, to describe the number of vaccination visits made by undervaccinated children and the number of visits needed to be series complete, and to describe the children who did not receive the single dose of measles-containing vaccine recommended for preschoolers.

METHODS

We used the 1999 National Immunization Survey (NIS) to describe vaccination coverage for the 4:3:1:3 vaccine series (four doses of diphtheria and tetanus toxoids and pertussis vaccine, three doses of poliovirus vaccine, one dose of any measles-containing vaccine, and three doses of Haemophilus influenzae type b vaccine) among non-Hispanic, African-American preschoolers due to concerns that they may be at risk of undervaccination. Children who did not complete this basic vaccine series were classified for further analysis according to the number of doses they lacked (i.e., one dose missed, two or three doses missed, or four or more doses missed). Significant associations between demographic characteristics and vaccination status or degree of undervaccination were determined.

RESULTS

Of the 26.2% of African-American preschoolers who did not complete the 4:3:1:3 vaccine series, 40.3% lacked one, 35.3% lacked two or three, and 25.0% lacked four or more doses of vaccine. Children who did not complete the 4:3:1:3 vaccine series were less likely to have married mothers, were less likely to have mothers aged > or = 35 years, or were less likely to be up to date at age 3 months than the children who completed the 4:3:1:3 vaccine series. Among the undervaccinated, 63.7% had a sufficient number of vaccination visits to have completed the basic series. However, most (78.7%) of the severely undervaccinated (children who lacked more than three doses of vaccine) had three or fewer vaccination visits. For 72.6% of the undervaccinated preschoolers, only one additional vaccination visit was needed to complete the 4:3:1:3 vaccine series; among these, 78.3% had an adequate number of vaccination visits to have completed the series. Overall, 9.9% of the African-American children aged 19 to 35 months (i.e., approximately 85,000 African-American children aged 19 to 35 months) were at risk for measles. Among the children who lacked more than three doses of vaccine, 68.1% were at risk.

CONCLUSIONS

Our study suggests that the estimated coverage of 73.8% for the 4:3:1:3 vaccine series among African-American children aged 19 to 35 months was not a result of limited access to care. On the contrary, 90.5% of African-American children had enough vaccination visits to complete the series. To raise coverage and prevent potential outbreaks, providers should assess each child's vaccination status at every visit, and administer all needed vaccinations at that time. For the most severely undervaccinated children, this strategy may not be adequate, because they did not have the minimum number of vaccination visits required for series completion. For these children, other strategies are needed for increasing vaccination coverage.

Variation in clinician recommendations for multiple injections during adoption of inactivated polio vaccine

OBJECTIVES

To describe variation in clinician recommendations for multiple injections during the adoption of inactivated poliovirus vaccine (IPV) in 2 large health maintenance organizations (HMOs), and to test the hypothesis that variation in recommendations would be associated with variation in immunization coverage rates.

DESIGN

Cross-sectional study based on a survey of clinician practices 1 year after IPV was recommended and computerized immunization data from these clinicians' patients. STUDY SETTINGS: Two large West Coast HMOs: Kaiser Permanente in Northern California and Group Health Cooperative of Puget Sound.

OUTCOME MEASURES

Immunization status of 8-month-olds and 24-month-olds cared for by the clinicians during the study.

RESULTS

More clinicians at Group Health (82%), where a central guideline was issued, had adopted the IPV/oral poliovirus vaccine (OPV) sequential schedule than at Kaiser (65%), where no central guideline was issued. Clinicians at both HMOs said that if multiple injections fell due at a visit and they elected to defer some vaccines, they would be most likely to defer the hepatitis B vaccine (HBV) for infants (40%). At Kaiser, IPV users were more likely than OPV users to recommend the first HBV at birth (64% vs 28%) or if they did not, to defer the third HBV to 8 months or later (62% vs 39%). In multivariate analyses, patients whose clinicians used IPV were as likely to be fully immunized at 8 months old as those whose clinicians used all OPV. At Kaiser, where there was variability in the maximum number of injections clinicians recommended at infant visits, providers who routinely recommended 3 or 4 injections at a visit had similar immunization coverage rates as those who recommended 1 or 2. At both HMOs, clinicians who strongly recommended all possible injections at a visit had higher immunization coverage rates at 8 months than those who offered parents the choice of deferring some vaccines to a subsequent visit (at Kaiser, odds ratio [OR]: 1.2; 95% confidence interval [CI]: 1.0-1.5; at Group Health, OR: 1.8; 95% CI: 1.1-2.8).

CONCLUSIONS

Neither IPV adoption nor the use of multiple injections at infant visits were associated with reductions in immunization coverage. However, at the HMO without centralized immunization guidelines, IPV adoption was associated with changes in the timing of the first and third HBV. Clinical policymakers should continue to monitor practice variation as future vaccines are added to the infant immunization schedule.

The impact of record scattering on the measurement of immunization coverage

BACKGROUND

Lack of a consolidated immunization record may lead to problems with determining individual immunization needs at office visits as well as measuring vaccination coverage levels of a clinician's practice or a community's population.

OBJECTIVES

For children with multiple immunization providers, evaluate the difference in coverage levels using data from all responding immunization providers compared with: 1) the most recent immunization provider's records, 2) the first immunization provider's records, and 3) a randomly selected immunization provider's records. Identify characteristics of the most recent provider that may be associated with reporting incomplete immunization histories.

METHODS

Data from the 1995 National Immunization Provider Record Check Study (NIPRCS) were used for analysis. The NIPRCS is a provider validation study of the household reported immunization histories of all children 19 to 35 months of age included in the National Health Interview Survey (NHIS). Providers identified by the child's parent during the NHIS interview are mailed a 2-page survey to report all immunizations (type and date) the child received, regardless of the provider who administered the shots, and child's first and most recent visit dates to the practice.

RESULTS

Of the 1352 children with provider data, 304 (22%) had received immunizations from more than one provider. Compared with information from all providers and depending on the vaccine, the most recent provider records underestimated coverage by 9.6 to 13.4 percentage points; the initial provider records underestimated coverage by 15.6 to 34.6 percentage points; and the randomly selected provider records underestimated coverage by 10.0 to 20.7 percentage points. Public facilities and having an immunization summary sheet in the patient's chart were associated with having complete records.

CONCLUSION

Scattered immunization records significantly compromise the ability of clinicians to determine the immunization status of their patients who received immunizations at other sites of health care. Routinely assessing immunization coverage levels at the practice level, implementing a recall system, and developing community-wide immunization registries are some strategies to reduce the problem of scattered immunization records.immunization, assessment, provider validation, record scattering.

Immunization coverage among predominantly Hispanic children, aged 2-3 years, in central Los Angeles

PURPOSE

To assess the immunization status of young children in a predominantly Hispanic region in and around downtown Los Angeles, and factors associated with complete immunization by age 24 months.

METHODS

The information was gathered in a two-stage cluster survey with probability proportionate to estimated size (PPS) sampling of 30 clusters at the first stage, and simple random sampling of a constant number of children at the second stage. Vaccination coverage was determined by a review of the home immunization (HI) card, or of clinic records.

RESULTS

Of the 270 sampled children, 91.5% were Hispanic and 6.7% were Black. Home telephone numbers were not available in 24.8% of the homes, and 34.1% reported having no health insurance. Vaccination coverage was over 90% for the first three doses of Diphtheria, tetanus toxoids and pertussis/ diphtheria, tetanus toxoids and acellular pertussis vaccine (DTP/DTaP)/Diphtheria and tetanus toxoids vaccine (DT), first two doses of poliovirus (Polio) vaccine, first dose of measles, mumps and rubella (MMR) vaccine, and first two doses of hepatitis B (Hep B) vaccine. Yet, by age 24 months, only 72.2% of the children had received the combined series of 4:3:1 (i.e., four DTP/DTaP/DT, three Polio, one MMR). This was further reduced to 64.4% for the combined series of 4:3:1:3:3 (i.e., four DTP/DTaP/ DT, three Polio, one MMR, three Haemophilus influenzae type b (Hib), three Hep B). Factors associated with completed on-time vaccination were having an HI card available during the interview and being enrolled in Supplemental Nutrition Program for Women, Infants and Children (WIC).

CONCLUSIONS

While vaccination levels for individual antigens were found to be high, more emphasis needs to be placed on getting preschool children vaccinated on-time according to the Recommended Childhood Immunization Schedule.

Minimum time interval adjustment for 4-3-1 immunization rates among two-year-old children

BACKGROUND

The purpose is to determine the administrative validity of the 4-3-1 immunization rates for DPT-OPV-MMR vaccines for 2-year-old children in a community health status assessment project by accounting for premature administration of specific vaccine doses according to ACIP recommended minimal timing intervals.

METHODS

A retrospective survey of immunization certificates was made on a random sample of 1,059 kindergarten enrollees in the county, including public, private, and parochial schools. The immunization rates by the crude 4-3-1 counting method were compared with the same method adjusted for minimal time interval vaccine dosing.

RESULTS

By the crude 4-3-1 counting method, 55.5% of the students had complete immunizations by their second birthdate, and 11.8% did not meet the minimum interval recommendations on at least one of 4-3-1 vaccine series. The adjustment for minimum time interval reduced the percent in compliance with the 4-3-1 counting method by age 2 in the community to 50.7%.

CONCLUSION

The premature timing of vaccine doses is a threat to the validity of the 4-3-1 counting method. The crude 4-3-1 method over-estimates the completed immunization rates for 2-year-olds in this community-based study by about 4.8%.

An integer programming model for vaccine procurement and delivery for childhood immunization: a pilot study

The National Immunization Program of the Centers for Disease Control and Prevention has identified several challenges that must be faced in childhood immunization programs to deliver and procure vaccines to protect against the common preventable diseases. The biomedical challenge is how to combine and formulate products to take advantage of new vaccines without requiring additional injections. A programmatic challenge is to incorporate then into already crowded immunization schedules. The economic challenge is to make wise procurement choices from among a growing number of competing products. This paper reports the results of a pilot study using operations research methodologies to address the third of these challenges. The pilot is an integer programming model for procuring vaccines for a set of childhood diseases. The model is studied under various scenarios (minimum total cost, next lowest total cost, maximum total cost, minimum total cost with all manufacturers represented). The results of this pilot study demonstrate how a practical set of operations research tools can be developed to guide vaccine selection and procurement, which might stimulate the development of innovations in new vaccines to meet the challenges of disease control through immunization.

Do missed opportunities stay missed? A 6-month follow-up of missed vaccine opportunities in inner city Milwaukee children

OBJECTIVES

To determine 1) the frequency of missed vaccine opportunities (VOs) in inner city children </=3 years of age; 2) whether the recommended vaccine(s) were given within 6 months of the missed opportunity (MO); 3) whether these vaccinations were age-appropriate according to the guidelines of the Advisory Committee on Immunization Practices; and 4) variables associated with MOs.

DESIGN

Retrospective chart review with a nested retrospective cohort of children with MOs.

SETTING

Two inner city practice settings in Milwaukee: a community health center and an academic continuity care practice. PATIENTS/SELECTION PROCEDURE: A consecutive sample of 710 visits of inner city children </=3 years of age with VOs, seen between January 1 and March 31, 1995. A VO was defined as any encounter when the child was vaccine-eligible according to Advisory Committee on Immunization Practices guidelines.

RESULTS

MOs occurred in 47% (330/710) of the VOs. Only 40% of the children with MOs received age-appropriate immunizations within 6 months; 30% received the vaccinations beyond the age-appropriate time. The remaining 30% either did not return or were not vaccinated on return. The variables significantly associated with MOs were 1) age: children with MOs were older than those without, with a mean age of 15.5 months vs 10.9 months; 2) minor febrile illness; 3) moderate/severe illness; 4) acute illness encounters; and 5) patient's being seen at the community health center. Only 15.5% of all MOs were justified by the presence of moderate/severe illness.

CONCLUSIONS

VOs are frequently missed in inner city children. Most of the MOs were not justified by the valid contraindication of moderate/severe illness. Sixty percent of the children with MOs did not receive age-appropriate immunizations within 6 months. These children are vulnerable to vaccine-preventable diseases such as measles and pertussis.

A population-based study of access to immunization among urban Virginia children served by public, private, and military health care systems

BACKGROUND

Pediatric immunization rates have increased in the United States since 1990. Nevertheless, national survey data indicate that up to one third of 2-year-old children in some states and urban areas lack at least one recommended dose of diphtheria-tetanus-pertussis (DTP)-, polio-, or measles-containing vaccines. Immunization has become a key measure of preventive pediatric health care in the United States. To achieve and maintain the national immunization goal that 90% of children receive all recommended immunizations by 2 years of age, the role of the health care system in immunization delivery must be examined. Urban eastern Virginia has a diverse population that obtains immunization services from public, private, and military providers and insurers. At the time of this survey, immunization services in Virginia were available free to all children through public health clinics and to military families when using a military facility.

OBJECTIVE

To examine access to pediatric immunization services and health system factors associated with underimmunization in a representative sample of children at 12 and 24 months of age.

METHODS

We conducted a household survey in urban eastern Virginia from April through September 1993. A total of 12 770 households in Norfolk and Newport News, VA, were selected for inclusion in the study using probability-proportionate-to-size cluster sampling. Use of probability-proportionate-to-size sampling ensured that children within each city had equal probability of being included in the survey. Selected households were visited by trained interviewers to determine their eligibility, defined as having at least one child 12 to 30 months of age residing in the household. In eligible households, parents were asked to participate in a standardized, 15-minute interview. Survey respondents were asked about household demographics, and for each eligible child, the immunization history, health insurance, the name and location of all immunization providers, the usual immunization provider, and any problems the parent had experienced accessing immunization services with that child. Up-to-date (UTD) immunization status was defined as having all recommended doses of DTP, polio, and measles-mumps-rubella at 12 months (three DTP and two polio immunizations) and 24 months (four DTP, three polio, and one measles-mumps-rubella immunizations). The child's immunization history was assessed from parent and provider records only. Data analysis accounted for the survey's cluster sampling design (ie, within-cluster correlation). Because the immunization rates of the two cities did not differ significantly, unweighted analyses were used for ease of computation. Significance was determined for contingency tables by Wald's chi2 test.

RESULTS

A total of 749 children (91% of eligible households) participated in the survey. Study children were born between October, 1990, and July, 1992. Immunization records were obtained for 705 children (94%). Eighty-seven percent of respondents were mothers, 44% were African-American, 40% of children were military dependents, and 40% were enrolled in the Women, Infants and Children (WIC) program. Sixty-five percent of children were UTD at 12 months and 53% at 24 months. Parents reported that their children's usual immunization providers were private doctors (34%); public health, hospital clinics, or community health centers (32%); and military clinics or a military contract provider (34%). At least one problem accessing immunization services was reported by 35% of respondents, ranging from 29% among those who used a private doctor as their child's usual immunization provider to 46% among those using a military contract provider. Overall, the most commonly reported problem was clinic waiting time (12%), with reports of waiting time as a problem occurring most often among those using the military contract provider (22%) and public health clinics (17%). (ABSTRACT TRUNCATED)

Vapocoolant spray is equally effective as EMLA cream in reducing immunization pain in school-aged children

BACKGROUND

Untreated immunization pain causes undue distress and contributes to underimmunization through physician, and possibly parental, resistance to multiple simultaneous injections.

OBJECTIVE

To compare the efficacies of two pain management methods in reducing immediate immunization injection pain and distress in school-aged children.

DESIGN

A randomized, controlled clinical trial of eutectic mixture of local anesthetics (EMLA) cream and vapocoolant spray.

PATIENTS

Children aged 4 to 6 years and scheduled to receive diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) during health supervision visits.

INTERVENTIONS

Enrolled children were randomized to one of three treatment groups: 1) EMLA cream + distraction; 2) vapocoolant spray + distraction; or 3) distraction alone (control). The specific pharmacologic pain control interventions consisted of EMLA cream (2.5% lidocaine, 2.5% prilocaine [Astra Pharmaceutical Products, Inc, Westborough, MA] $15. 00/patient; applied 60 minutes before injection) and vapocoolant spray (Fluori-Methane [Gebauer Company, Cleveland, OH] $0. 50/patient; applied via spray-saturated cotton ball for 15 seconds immediately before injection).

MAIN OUTCOME MEASURES

The blinded investigator (BI) measured (by edited videotape) cry duration and the number of pain behaviors using the Observational Scale of Behavioral Distress. Pain visual analog scales (linear and faces scales) were completed by the child, parent, nurse, and the BI.

RESULTS

Sixty-two children, aged 4.5 +/- 0.4 years (mean +/- SD) were randomized. The three treatment groups had similar subject characteristics. All pain measures and cry duration were similar for EMLA and vapocoolant spray. Both EMLA and spray were significantly better than control. Results for spray vs control: cry duration (seconds): 8.5 +/- 21.0 vs 38.6 +/- 50.5; number of pain behaviors: 1.2 +/- 1.9 vs. 3.1 +/- 2.1; child-scored faces scale: 2.0 +/- 2.4 vs. 4.1 +/- 2.3; parent-scored faces scale: 1.6 +/- 1.6 vs. 3.0 +/- 1.7; nurse-scored faces scale: 1.6 +/- 1.2 vs. 3.1 +/- 1.4; and BI-scored faces scale: 1.0 +/- 1.5 vs. 2.4 +/- 1.4.

CONCLUSIONS

When combined with distraction, vapocoolant spray significantly reduces immediate injection pain compared with distraction alone, and is equally effective as, less expensive, and faster-acting than EMLA cream. As an effective, inexpensive, and convenient pain control method, vapocoolant spray may help overcome physician and parent resistance to multiple injections that leads to missed opportunities to immunize.

Comparing a computer-based childhood vaccination registry with parental vaccination cards: a population-based study of Delaware children

We conducted a population-based study in Delaware to examine the reliability of childhood vaccination data in a comprehensive computer-based record system versus parental vaccination cards. We sampled 1,005 children born between January, 1991, and September, 1993. We oversampled for children whose mothers received Medicaid or were uninsured at the time of delivery. Of the survey responders, 276 (56%) had access to written records, and 409 (83%) records were located in the Delaware immunization computer database. The kappa coefficient was 0.18. The observed agreement was 59.8%. When the two databases were combined, the up-to-date rate for 2-year-olds was 58.4%, an increase of 12.7% and 24.2% from the computer database and the parental records, respectively. The computer database was 78.1% sensitive and the parental records were 54.9% sensitive. These results indicate that a comprehensive computer-based record system, with adequate provider participation and proper data management, can be more reliable than parental vaccination cards.

Factors associated with unnecessary immunization given to children

OBJECTIVE

To determine the factors associated with unnecessary immunization during the pre-school years.

METHODS

Children were selected from birth certificates and their parents were interviewed to identify all immunizations to 72 months of age. The immunizations were verified.

RESULTS

Of 187 children studied 34 (18%) received unnecessary immunization. Unnecessary immunization was strongly associated with ever receiving immunization in a large system of public clinics (designated "Public A") (33%) compared with other providers (5%) (P < 0.00001). Among children immunized in Public A, unnecessary immunization was associated with the parent having an incomplete or no copy of the child's immunization record (P = 0.007) and with not being up to date for immunizations at 24 months of age (P = 0.04). Complete documentation of immunizations either in the Public. A record or in the parent's copy of the record was associated with a 4% rate of unnecessary immunization; incomplete or no documentation in both the Public A and the parent's record was associated with a 45% rate of unnecessary immunization (P = 0.001).

CONCLUSIONS

Access to a complete immunization record, be it the provider's, the parent's or ideally both, decreases substantially a child's risk of unnecessary immunization.