Respiratory syncytial virus and premature infants born at 32 weeks' gestation or earlier: hospitalization and economic implications of prophylaxis

OBJECTIVES

To assess the risk of hospitalization associated with respiratory syncytial virus (RSV) and to estimate the economic impact of RSV prophylaxis with either RSV immune globulin (RSV-Ig) or RSV monoclonal antibody (palivizumab) on a cohort of preterm infants born at 32 weeks' gestation or earlier.

DESIGN

Historical cohort study.

SETTING

A 12-county neonatal network served by the regional center in Rochester, NY.

PARTICIPANTS

One thousand twenty-nine infants born at 32 weeks' gestation or earlier followed up until 1 year of corrected age.

MAIN OUTCOME MEASURES

Rate of hospitalization with an RSV-associated illness; cost per hospitalization prevented resulting from either form of RSV prophylaxis.

RESULTS

The probability of hospitalization with an RSV-associated illness for infants born at 32 weeks' gestation or earlier was estimated at 11.2%. The incidence of RSV hospitalization increased with decreasing gestational age (13.9% vs 4.4% for infants born at < or =26 weeks' gestation vs those born at 30-32 weeks' gestation). Infants requiring respiratory support at 36 weeks of postconceptual age (PCA) or older had a higher hospitalization rate (16.8% vs 6.2%), longer hospital stays, and higher hospital charges than infants requiring respiratory support at less than 36 weeks of PCA. For infants requiring respiratory support at less than 36 weeks of PCA, the incidence of RSV hospitalization still increased with decreasing gestational age (10.2% vs 4.3% for infants < or =26 weeks' gestation vs those 30-32 weeks' gestation). Analysis indicated that both forms of RSV prophylaxis would increase the net cost of care for all groups. Palivizumab was more cost-effective than RSV-Ig for preventing RSV hospitalization among infants who required respiratory support at less than 36 weeks of PCA, especially those born at 26 weeks' gestation or earlier. Overall, RSV-Ig was more cost-effective than palivizumab for infants requiring respiratory support at 36 weeks of PCA or older.

CONCLUSIONS

This analysis suggests that available forms of RSV prophylaxis would increase the net cost of care not only for the entire cohort but for each of the subgroups studied. However, the RSV hospitalization rate and the cost-effectiveness of prophylaxis varied markedly by subgroup.

How commonly are children hospitalized for dehydration eligible for care in alternative settings?

BACKGROUND

Avoiding unnecessary hospitalization has long been a goal of child health care providers. Managed care practice environments increasingly pressure the practicing pediatrician to avoid hospitalization.

OBJECTIVES

To estimate the proportion of childhood dehydration hospitalizations eligible for care in alternative settings (eg, short-stay treatment and triage units, home nursing) and to assess the type and duration of services that might be required for alternative setting care of children with these illness episodes.

DESIGN

All dehydration hospitalizations for the 198 593 children (aged > 1 month and < 19 years) dwelling in Rochester, NY (Monroe County), between 1991 and 1995 were identified in county-wide hospital discharge computer files. Medical records were reviewed for a random sample of 380 of the hospitalizations. Children with major underlying conditions were excluded from analysis because of higher risk for deterioration, and greater complexity of medical care might render alternative settings inappropriate. Measures included a 4-item score estimating level of dehydration, serum bicarbonate level at presentation, and time to rehydration. Rehydration was defined as a drop in urine-specific gravity to 1.010 or less or reduction of fluid administration to the maintenance rate.

RESULTS

Altogether, 1121 dehydration hospitalizations occurred during the study period. Based on medical record review for a random sample of 380 of these 1121, major underlying problems were present in 27.4% (104) of hospitalizations sampled. Simple, acute gastroenteritis accounted for 75.4% (208) of 276 hospitalizations remaining in the sample. Levels of dehydration for these children were estimated as at least 5% for 51.0% (106) and at least 10% for 16.3% (34) of hospital admissions, and serum bicarbonate levels were 12 mmol/L or less for 26.0% (54). Time from hospital admission to rehydration was no greater than 12 hours for 79.3% (165) and no greater than 24 hours for 94.7% (197). However, hospital stay was generally substantially longer. The time hospitalized following rehydration represented 85.8% of the average inpatient stay. Hospital discharge was heavily concentrated in daytime hours, although the children achieved rehydration at all hours of the day. No deterioration occurred during hospitalizations studied.

CONCLUSION

Nearly all children hospitalized for simple, acute gastroenteritis in Rochester might be eligible for care in alternative settings designed to provide hospital-level care for short periods.

Increase in admission threshold explains stable asthma hospitalization rates

BACKGROUND

Asthma morbidity and mortality has increased substantially in recent years, but asthma hospitalization rates among many geographic and sociodemographic groups have remained stable. Observations on asthma hospitalization rates and severity of acute episodes might provide valuable insight into the functioning of the health care system during this period of health care reform.

OBJECTIVE

To analyze changes between 1991 and 1995 in childhood asthma hospitalization rates and severity of acute episodes.

DESIGN AND METHODS

All 29 329 hospitalizations, including 2028 for asthma, for the 198 893 children (<19 years of age) in Monroe County (Rochester), New York, were studied during this 5-year period. Severity was determined by hospital record review on a 22% random sample. Using the worst oxygen saturation (SaO(2)) during the first 24 hours of hospitalization as the primary index of severity, episodes were categorized as mild (0 to >/=95), moderate (90 to 94), or severe (<90).

RESULTS

Hospitalization rates are expressed as hospitalizations per 1000 child-years. The overall asthma hospitalization rate was 2.04 (95% confidence interval, 1.95-2.13). The overall annual asthma hospitalization rate remained relatively stable from 1991 (1.90) to 1995 (2.31), whereas the hospitalization rates for severe asthma rose 270%-from 0.57 to 1.55-during this period. Simultaneously, the hospitalization rates for mild asthma decreased from 0.26 to 0.12. As a proportion of all asthma hospitalizations between 1991 and 1995, severe episodes increased from 31.5% to 60.4%; conversely, mild episodes decreased from 14.1% to 4.7%.

CONCLUSIONS

Severity increased significantly among children hospitalized for asthma while the overall asthma hospitalization rate remained stable. It seems that the health care system in this community has responded to an increase in severity of asthma by raising the severity threshold for admission.

Predicting deterioration in previously healthy infants hospitalized with respiratory syncytial virus infection

OBJECTIVE

To estimate the incidence of clinical deterioration leading to intensive care unit transfer in previously healthy infants with respiratory syncytial virus (RSV) infection hospitalized on a general pediatric unit and, to assess the hypothesis that history, physical examination, oximetry, and chest radiographic findings at time of presentation can accurately identify these infants.

STUDY DESIGN

A virology database was used to identify and determine the disposition of all children </=1 year of age admitted to the Children's Hospital at Strong (CHaS) with RSV infection during the 1985 to 1994 respiratory seasons. Index patients were all previously healthy, full-term infants admitted initially to the general inpatient services at CHaS or Rochester General Hospital, a second University of Rochester teaching hospital, whose clinical deterioration led to transfer to the pediatric intensive care unit (PICU). These infants were matched retrospectively (for year and date of infection, sex, chronologic age, and race) with two hospitalized controls who did not require PICU transfer. Chest radiographic findings, respiratory rate (RR), O(2) saturation, and presence of wheezing at time of presentation to the emergency department (ED) were compared.

RESULTS

During the study years, 542 previously healthy, full-term infants were admitted to the general pediatric unit at CHaS with proven RSV infection. Ten (1.8%; 95% confidence interval, 0.9%, 3.4%) were transferred subsequently to the PICU, primarily for close monitoring of progressive respiratory distress. Data for these patients and 7 patients transferred from Rochester General Hospital to the PICU at the CHaS were compared with those for control patients. The mean RR in the ED (63 vs 50), and O(2) saturation in the ED (88% vs 93%) were modestly abnormal in cases compared with controls. Wheezing on examination at time of presentation and chest radiographic findings did not differ between the two groups. A RR >80 and an O(2) saturation <85% at time of presentation each had a specificity >97% for predicting subsequent deterioration. Each parameter, however, had a sensitivity </=30%.

CONCLUSION

Clinical deterioration requiring PICU admission is an uncommon occurrence in previously healthy infants admitted to a general pediatric inpatient unit with RSV infection. Extreme tachypnea and hypoxemia were both associated with subsequent deterioration; however, only a small proportion of patients who clinically deteriorated presented in this way. The clinical usefulness of these parameters, therefore, is limited. respiratory syncytial virus, deterioration, healthy infants, prediction.

Socioeconomic variation in asthma hospitalization: excess utilization or greater need?

OBJECTIVE

To assess the hypothesis that higher incidence of severe acute asthma exacerbation, not lower severity threshold for admission, explains the difference between the asthma hospitalization rates of inner-city and suburban children.

METHODS

All 2028 asthma hospitalizations between 1991 and 1995 for children (aged >1 month and <19 years) dwelling in Rochester, New York, were analyzed. ZIP codes defined residences as inner-city, other urban, or suburban. Based principally on the worst oxygen saturation (SaO2) during the first 24 hours of hospitalization, severity was examined by hospital record review (n = 443) of random samples of inner-city, other urban, and suburban asthma admissions.

RESULTS

Large inner-city/suburban differences were noted in many sociodemographic attributes, and there was also a distinct, stepwise gradient in risk factors in moving from the suburbs to other urban areas and to the inner city. Racial and economic segregation was particularly striking. Black individuals accounted for 62% of inner-city births versus <3% in the suburbs. Medicaid covered 65% of inner-city births, whereas Medicaid covered only 6% of suburban births. The overall asthma hospitalization rate was 2.04 admissions/1000 child-years. Children <24 months old, those most commonly hospitalized for asthma, were fourfold more likely to be hospitalized (OR: 3.97, 95% CI: 3. 44-4.57) than children between the ages of 13 and 18 years. The hospitalization rate of asthma in boys was almost twice the rate of asthma in girls. The greatest gender difference was observed among children who were <24 months old. For these children, the rate for boys was 6.10/1000 child-years compared with 2.65/1000 child-years for girls (OR: 2.31, 95% CI: 1.95-3.03). This gender difference diminished gradually in older age groups to the extent that there was no difference among girls and boys between the ages of 13 and 18 years (males, 1.12/1000 child-years vs females, 1.09/1000 child-years). Based on worst SaO2 values, mild (worst SaO2 >/=95%), moderate (90%-94%), and severe (<90%) admissions constituted 10.3%, 41.9%, and 47.7% of all hospitalizations, respectively. Although rates within the community followed a distinct geographic pattern of suburban (1.05/1000 child-years) < other urban (2.99/1000 child-years) < inner-city (5.21/1000 child-years), the proportions of admissions with low severity did not vary among areas. Likewise, the proportions of admissions that were severe (SaO2 <90%) were not significantly different (44.8, 45.7, and 52.1% for suburban, other urban, and inner-city areas, respectively). The distributions of asthma severity, measured by the duration of frequent nebulized bronchodilator treatments and the length of hospital stay, were also similar among children from different socioeconomic areas.

CONCLUSION

The marked socioeconomic and racial disparity in Rochester's asthma hospitalization rates is largely attributable to higher incidence of severe acute asthma exacerbations among inner-city children; it signals greater need, not excess utilization. Both adverse environmental conditions and lower quality primary care might explain the higher incidence. Interventions directed at the environment offer the possibility of primary prevention, whereas primary care directed at asthma is focused on secondary prevention, principally on improved medication use. Higher hospitalization rates cannot be assumed to identify opportunities for cost reduction. The extent to which our observations about asthma hold true under other conditions and in other communities warrants systematic attention. Knowledge of when higher rates signal excess utilization and when, instead, they signify greater needs should guide equitable national health policy.

How commonly are children hospitalized for asthma eligible for care in alternative settings?

OBJECTIVE

To estimate the proportion of children hospitalized for acute asthma exacerbation who might be cared for successfully in alternative settings such as short-stay units or in-home nursing.

DESIGN

Descriptive study based on analysis of hospital discharge files and on retrospective medical record review of a random sample of asthma hospitalizations.

METHODS

The 2028 asthma hospitalizations between 1991 and 1995 for children (aged <19 years) dwelling in Rochester, NY, were studied. Measures included the duration of frequent administration of nebulized medication (2 or more times in a 4-hour period), worst oxygen saturation levels, deterioration, and hospital length of stay. Oxygen saturation values and nebulized medication frequency were determined by hospital record review on a random sample of 443 asthma episodes. Length of stay was available for all admissions.

RESULTS

Worst oxygen saturation following hospital admission was 95% or greater, 90% to 94%, and less than 90% for 21.3%, 51.6%, and 27.1% of episodes, respectively. Children received frequent nebulized medication treatments for a mean of 2.0 nursing shifts (8 hours per shift), although they remained hospitalized, on average, for 4.3 nursing shifts longer. Deterioration to a critical level of severity was uncommon. Among children initially admitted to the regular pediatric inpatient unit, only 0.7% subsequently deteriorated to the point that they were transferred to the critical care unit.

CONCLUSION

More than 70% of asthma hospitalizations in this community could be cared for in alternative settings with supplemental oxygen, nebulized medication treatments, and close nursing observation provided, in most cases, for 2 nursing shifts.

Diagnostic clusters in infants as child health outcomes. Variation among socioeconomic areas in one community

Objectives were to examine geographic variation in rates of infant hospitalization for diagnostic clusters in Monroe County (Rochester), New York and to assess these clusters as indexes of child health. ICD-9 codes were used to cluster all 7,883 hospitalizations of infants (< 24 months) between 1985 and 1991 on the basis of their avoidability. Environmentally sensitive clusters accounted for 63% of admissions. These clusters included environmental, environmental/constitutional, and other infectious disease. Disparities in morbidity between inner city and suburbs were greatest for the environmental cluster, followed by the environmental/constitutional, and other infectious disease clusters. For the constitutional and quality indicator clusters, differences between inner-city and suburban risk were minimal. Environmental interventions may be more important than improved health services to reducing racial and economic disparities in child health. Analysis of morbidity clusters, ascertained from available administrative data bases and aggregated for small geographic areas, may guide child health policy well.

Estimating risk associated with care in alternative settings: deterioration among children hospitalized

BACKGROUND

Although managed care favors use of alternative settings in an attempt to avoid hospitalization, uncertainty about possible deterioration creates concern about their safety.

OBJECTIVE

To derive preliminary estimates for the risk of adverse outcome in children hospitalized with acute illness who met criteria for admission to potentially less-expensive, alternative settings (eg, short-stay unit, home nursing).

DESIGN

Description of hospitalization outcomes for a community-wide childhood population.

SETTING AND POPULATION

All 11591 hospitalizations for residents of Monroe County (Rochester), New York, aged 1 month to 18 years in 1991 and 1992.

MEASUREMENTS

To identify potential adverse outcomes in alternative settings (numerator estimate), hospital medical records for admissions to regular inpatient units were examined. To ascertain deterioration among these admissions, detailed record reviews were conducted if the child died or was transferred to another hospital or to a critical care unit. To estimate the total number of admissions eligible for care in alternative settings (denominator estimate), hospital discharge files were analyzed.

RESULTS

Deterioration was found in 83 medical admissions. Of these 83, major chronic problems (n=53) or severe illness at presentation (n=27) precluded alternative setting eligibility, leaving only 3 in whom alternative setting care might have been considered. The total number of admissions eligible for alternative setting care was estimated between 1661 (restrictive criteria) and 3322 (inclusive criteria) for the 2-year observation period. Based on these observations, best- and worst-case estimates for the risk of deterioration in candidates for care in alternative settings were 0.6 and 1.8 per 1000, respectively. For the 3 children for whom alternative setting care might have been considered, the shortest period from first indication of deterioration to arrival in the critical care unit was 3.0 hours.

CONCLUSIONS

These preliminary estimates suggest that alternative settings may be safe for the care of many children currently hospitalized. A randomized clinical trial to evaluate directly the potential benefits and harms of alternative setting care should be considered.

Resident and family continuity in pediatric continuity clinic: nine years of observation

OBJECTIVE

To assess resident, patient, and family continuity.

BACKGROUND

Continuity clinic is the principal longitudinal primary care experience for pediatric residents. Although it has been a recommendation of the Residency Review Committee for pediatric training for more than 10 years and has been a requirement of the Accreditation Council of Graduate Medical Education since 1989, the extent to which continuity is achieved in this setting has not been reported.

METHODS

Nine years (1984-1993) of residents' continuity clinic experience in a community hospital affiliate of a university training program were reviewed. Continuity was defined by recurring visits between the same patient/provider pair. The analysis from 57 different residents includes 48 intern (R1) years, 45 level two (R2) years, and 40 level three (R3) years; 32 of these residents completed all 3 years of training (3-year cohort) in the program during the study period. Observations included 89 952 visits by 11 009 patients in 7130 families. Continuity was determined for the resident, patient, and family.

RESULTS

Residents saw an annual average of 93, 136, and 144 visits as R1s, R2s, and R3s. Residents saw 60% of their patients fewer than 3 times and nearly 40% only once. In the final year for those in the 3-year cohort, residents saw an average of 149 visits; 53% of the time these R3s had seen their patients once or twice over 3 years. Thirty percent of the patients never saw their primary care physician (PCP) and 72% of patients had fewer than 3 visits with their PCP. One quarter of the families never saw their continuity resident, and 62% saw their continuity resident fewer than 3 times.

CONCLUSIONS

These data demonstrate a remarkable lack of both resident and patient continuity in the principal clinical activity affording longitudinal primary care experiences during residency training. If more continuity is essential for both primary care of patients and education in general pediatrics, change in the structure of continuity experience is required.

Decline of pediatric admissions with Haemophilus influenzae type b in New York State, 1982 through 1993: relation to immunizations

OBJECTIVES

To evaluate the impact of vaccination for Haemophilus influenzae type b (Hib) on pediatric hospital admissions in New York State, and to identify risk factors in children who continue to be admitted for Hib invasive disease.

METHODS

Retrospective review of hospitalizations in New York state from 1982 through 1993 and a survey of immunization records from physician offices in Monroe Country, New York.

RESULTS

In 1982, 769 children were admitted to New York state hospitals for Hib-related conditions; by 1993, this had decreased to 133. Significant declines during the study period occurred in the age-adjusted admission rates for Hib meningitis, septicemia, pneumonia, and epiglottitis, but not for arthritis and osteomyelitis. In 1993 alone, 712 admissions, 18 deaths, and 135 episodes of morbidity were avoided. Since 1991, the rates of admissions for Hib-related conditions have remained fairly constant. Minority subjects continue to be twice as likely as white subjects to be admitted for invasive Hib disease (0.44 vs 0.17/100,000). Children living in urban Rochester also are more likely to be admitted and less likely to be completely immunized against Hib (61%) than those living in suburban areas (82%).

CONCLUSIONS

Although Hib vaccine has had a major impact on hospital admissions for Hib-related conditions, the goal of completely eliminating Hib disease will require programs targeted at groups at high risk, such as minorities and those living in cities.

Socioeconomic variation in discretionary and mandatory hospitalization of infants: an ecologic analysis

OBJECTIVES

To examine geographic variation in rates of infant hospitalization for diagnoses classified by type of hospitalization decision in Monroe County (Rochester), New York.

METHODS

Study design was cross-sectional and ecologic. International Classification of Diseases (ICD) codes were used to categorize all 7883 hospitalizations for infants (age, <24 months) beyond the newborn period between 1985 and 1991. Postal zip codes defined socioeconomic areas as inner-city, other urban, and suburban for the population at risk. In 1990, inner-city infants included 62% black and 65% Medicaid-covered infants, whereas suburban infants included 3% black and 6% covered by Medicaid. Hospitalization rates were compared among the three socioeconomic areas.

RESULTS

Overall hospitalization rate was 50.3 per 1000 child years. Admissions classified as discretionary accounted for 59% of these, followed by those classified as mandatory, 18%; sometime (congenital heart disease, cleft palate), 15%; discretionary surgery (inguinal hernia, tonsillectomy/adenoidectomy), 6%; and unlikely to need admission, 2%. A stepwise, socioeconomic gradient in hospitalization was found, with rates of 38.1, 51.3, and 82.9 per 1000 child-years, respectively, for suburban, other urban, and inner-city areas. Rates for discretionary, unlikely, and mandatory admissions followed this gradient. Using the odds for hospitalization of suburban infants as the base odds, the odds ratio for discretionary hospitalization for inner-city infants was 2.88 (95% confidence interval [CI], 2.69 to 3. 08) and that for mandatory hospitalization was 2.20 (95% CI, 1.94 to 2.49). In multiple regression analysis, low education level of mothers explained 81% of the variance in discretionary hospitalization rate. Although the per capita rate of hospital care of inner-city infants was more than twofold greater than that for suburban infants, potential for reducing this difference is suggested by the fact that discretionary admissions accounted for 78. 9% of this difference, whereas mandatory admissions accounted for 17. 7% of the difference.

CONCLUSION

The hospitalization rate for inner-city infants is much greater than that for suburban infants. A substantial portion of the difference, namely that attributable to mandatory admissions, reflected higher rates of serious illness. Differences attributable to discretionary admissions may reflect higher rates of serious illness to some extent, but also appear to reflect less effective health services to a substantial degree.

Ensuring high-quality alternatives while ending pediatric inpatient care as we know it

Child advocates recognize pediatric hospitalization as an issue of great concern because of the serious morbidity it reflects and the adverse psychosocial effects of inpatient experience on children and families. Accounting for almost 50% of child health care costs, estimated at $49.8 billion in the United States in 1987, pediatric hospitalization also represents a substantial financial burden. Studies of the variation in childhood hospitalization rates among geographic areas, however, suggest a large portion of these hospitalizations are avoidable. In individual level analysis, admitting pediatricians judged 28% of acute, general pediatric hospitalizations to be potentially avoidable had specified alternative services been available. Furthermore, evidence supports the safety of care in alternative settings for selected acute illness episodes. Hospitals share incentives for reducing inpatient services as they join managed care organizations that capitate hospital costs. At a time when health care cost reduction has become a dominant theme in industry and politics, concern seems warranted that cost considerations might prevail over quality considerations in shaping change. The concern of child advocates is heightened by the fact that costs are measured as dollars while measures of quality remain comparatively vague.

Impact of an algorithm-guided nurse intervention on the use of immunization opportunities

OBJECTIVE

To determine if a nurse intervention guided by an immunization algorithm was associated with an increased use of immunization opportunities at non-well-child care visits.

DESIGN

A controlled intervention trial of an algorithm-guided nurse intervention during a 5-month period. The use of immunization opportunities at an intervention site was compared with the use at this site during the previous year (the retrospective control group) and with that at a similar pediatric practice during the same period (the concurrent control group).

STUDY POPULATION

Children aged 2 to 60 months at 2 hospital-based pediatric practices that serve children of families with low to moderate incomes in Rochester, NY.

RESULTS

During the study periods, 2814 study children in the 3 groups made 5464 visits for non-well-child care. The use of immunization opportunities for diphtheria-tetanus-pertussis vaccine, live oral poliovirus vaccine, and measles-mumps-rubella vaccine at intervention visits was significantly better than at the visits of the retrospective or concurrent control groups (range of odds ratios, 1.9-2.5).

CONCLUSIONS

An algorithm-guided nurse intervention improved the use of immunization opportunities at non-well-child care visits.

Severity of respiratory syncytial virus infection is related to virus strain

The relationship between respiratory syncytial virus (RSV) strain and disease severity was assessed in 265 hospitalized infants over a 3-year period (1988-1991). A severity index of clinical and physiologic parameters was used to grade illness severity. Multivariate analysis of 134 infants infected with group A RSV strains and 131 infants infected with group B strains indicated that prematurity, underlying medical conditions, group A RSV infection, and age < or =3 months were independently associated with severe disease. Odds ratios for severe disease for these risk factors were 1.83, 2.84, 3.26, and 4.39, respectively. Among infants without underlying medical conditions, group B RSV infection rarely required ventilatory support, in contrast to group A infections (1/90 vs. 13/107; P < .006), and had significantly lower severity indices (mean +/- SD, 0.6 +/- 9 vs. 1.3 +/- 1.9; P = .05). Results confirm earlier findings that group A RSV infection results in greater disease severity than group B infection among hospitalized infants.

Avoidable morbidity in infants. A classification based on diagnoses in administrative databases

OBJECTIVES

A hierarchical classification for avoidable morbidity in infants was developed based on a conceptual model for causes of morbidity. Experts rated the impact of risk factors and health services on diseases coded according to the International Classification of Diseases, 9th Revision, Classification Modification (ICD-9-CM). An etiologic framework was chosen for the classification because knowledge of etiology often suggests strategies for prevention. Causes of morbidity that cluster on the basis of similar risk factors might be avoided using similar strategies.

METHODS

Diseases (346 different diagnoses) were rated by 16 general pediatricians; 12 attributes were considered, including the impact on disease occurrence and on severity of five risk factors, preventive health services, and medical treatment. Raters evaluated the impact of health services, constitutional risk factors, and environmental risk factors without regard for service site (eg, inpatient, emergency department, primary care office). Environmental risk factors categories, including family, social, and physical environments, were rated separately. The impact of health services was rated on prevention, treatment, and complications of care.

RESULTS

Only ratings indicating that the impact of a risk factor category was substantial were used for the final classification of 275 diagnoses. Consistent with the multifactorial etiology of many diseases, many diagnoses had ratings indicating substantial impact of multiple risk factors. Five mutually exclusive clusters were derived from the 12 ratings based on factor analysis and recognized strategies for prevention. Ordered by level of avoidability, these clusters were termed vaccine-preventable, health-care quality indicators, environmental, environmental/constitutional, and constitutional.

CONCLUSIONS

The usefulness of this classification for policy-oriented epidemiologic and health services research is grounded in the premise that prevention is the cardinal objective of child health policy. Cluster-specific hospitalization rates, ie, rates aggregated for all diagnoses falling in a cluster, might be used for allocating resources to interventions directed at environmental or health service determinants of morbidity. Widespread use of ICD-9-CM codes in hospital discharge and ambulatory databases suggests many potential applications for this classification of morbidity burden in population groups.

Screening for tuberculosis infection in urban children

OBJECTIVES

To determine the proportion of children who are at high risk for tuberculosis (TB) as defined by the American Academy of Pediatrics (AAP) criteria, the rate of compliance with visits for tuberculin skin test (TST) interpretation, and the prevalence of TB infection.

DESIGN

A cross-sectional study of 401 children, 12 months to 18 years of age, who attended a hospital-based, urban pediatric clinic for well-child visits was undertaken from April 13, 1994, through August 30, 1994. Respondents completed a self-administered questionnaire, an intradermal TST was applied, and an appointment was scheduled for skin test interpretation in 48 to 72 hours.

SETTING

Hospital-based, pediatric primary care center in Rochester, NY, serving children of low to moderate income (67% were receiving Medicaid).

RESULTS

Of the 401 children, 342 (85%) had at least 1 risk factor for TB identified: 96 (24%) reported contact with persons who were considered to be at high risk for TB; 170 (42%) had at least 1 parent who was born in a high prevalence country; and 269 (67%) reported a household income of less than $15,500. Of the 401 children, 300 returned for TST interpretation, 257 (64%) by 48 to 72 hours and an additional 43 (11%) by 96 hours. Four (1.3%) of the 300 children had a positive TST (ie, induration > or = 10 mm). All 4 of the children who were TST positive had at least 1 parent from a high-risk country and were identified using AAP-defined risk criteria. The mean age of children who were TST positive was 15.3 years (range 13-17 years) compared with 8.1 years for those who were TST negative (P < .01). The positive predictive value of the questionnaire, which included income as a risk factor for TB, was only 1.5 (95% confidence interval = 0.5-4.0); when household income was not considered a risk factor, the positive predictive value was 2.0 (95% confidence interval = 0.7, 5.5). The estimated cost per child who was TST positive ranged from $430 for those who had contact with an incarcerated adult to $855 per child who was TST positive identified by using AAP-defined criteria.

CONCLUSIONS

The overall sensitivity of the AAP-defined criteria and having at least 1 parent from a TB-endemic country were high. However, because of the low prevalence of TB infection, the positive predictive value of these criteria was very low. These data support AAP recommendations only to skin test children who are at high risk for TB, but they also suggest that annual testing may not be cost-effective for many communities in the United States.

Hospitalization for lower respiratory tract illness in infants: variation in rates among counties in New York State and areas within Monroe County

OBJECTIVE

Lower respiratory tract illness (LRI) is the most common serious illness in childhood and the most common reason for hospitalization of infants beyond the neonatal period. This study assessed the potential for cost savings from reduction in hospitalization for LRI.

SETTING AND SAMPLE

LRI hospitalization rates for children in the first 2 years of life (infants) were studied for the 62 counties of New York State and six socioeconomic areas within Monroe County (Rochester) for the years 1985 through 1991.

DESIGN

Analysis of small area variations.

RESULTS

LRI accounted for 51.2% of infant hospitalizations in New York State. The overall LRI hospitalization rate for New York's 62 counties was 27.0 per 1000 child-years and ranged, among the 18 most populous counties, from 10.7 for Monroe County to 39.3 for the Bronx. Unemployment rate was the strongest predictor of LRI hospitalization rates for counties, explaining 29% of the variance in multiple regression analysis. Within Monroe County, LRI hospitalization rates followed a geographic gradient from the inner city (22.5) to the rest of the city (12.2), and to the suburbs (7.3). Deaths from LRI were uncommon (0.36% of state LRI hospitalizations) and varied little between inner city (0.42%) and suburbs (0.51%). If LRI hospitalization rates for Monroe County suburban children prevailed for the entire state, 10,439 hospitalizations and $32,916,000 would be saved annually.

CONCLUSIONS

A large portion of the increased cost of health care for children living in poverty is attributable to hospitalization for LRI in infants. Physician discretion in decision making and factors associated with socioeconomic status are probably major determinants of variation. Well-coordinated follow-up of acute illness visits, home monitoring by visiting nurses, and empirically based clinical guidelines for management of LRI might yield both substantial cost savings and better service to families.

Lead screening among high-risk urban children. Are the 1991 Centers for Disease Control and Prevention guidelines feasible?

OBJECTIVE

To determine whether the 1991 Centers for Disease Control and Prevention lead poisoning prevention guidelines for biannual screening and retesting are feasible among a high-risk population.

METHODS

For 632 urban high-risk children aged 9 to 25 months who used a pediatric primary care center between 1989 and 1991, we assessed physician screening practices and the need to increase utilization to meet guidelines for retesting. Analysis also focused on missed opportunities for lead screening. For 425 urban high-risk children who were long-term utilizers of the center, we assessed the need to increase utilization to meet guidelines for biannual screening.

RESULTS

Screening was not up to date in 55%, 34%, and 29% of children at ages 9 to 13 months, 14 to 19 months, and 20 to 25 months, respectively. These children had a mean of 2.3, 2.5, and 2.3 missed opportunities during each age period. Among children who had made well-child visits, in 41%, 36%, and 28% of children screening was not up to date at each age period. Between ages 13 and 37 months, 42% of long-term clinic utilizers made sufficient visits to achieve biannual screening. Sixty-five percent of children who were screened made a subsequent visit within 2 to 5 months, at which time retesting could have been performed.

CONCLUSIONS

At this primary care center, many high-risk children, including those who had made well-child visits, were not appropriately screened for lead toxic effects. Children not screened had many missed opportunities at all types of visits, including well-child visits. Many children visited frequently enough to achieve biannual screening and retesting without increased numbers of visits if non-well-child visits had been used as opportunities for retesting.

Developing prediction rules and evaluating observation patterns using categorical clinical markers: two complementary procedures

Substantial uncertainty often remains at the time that important diagnostic or therapeutic decisions must be made, despite the availability of multiple clinical indicators. Multiple indicators may be used to define observation patterns that are associated with the presence or absence of disease. Clinical prediction rules based on groups of observation patterns have been used to quantify probabilities and reduce error rates for some medical problems, but efficient use of multiple indicators remains a major challenge in medical practice. Medical outcomes and clinical observations are frequently categorical. Two statistical techniques appropriate for generating prediction rules from categorical data are logit analysis (LA) and recursive partitioning analysis (RPA). LA and RPA were compared in evaluating observation patterns for fractures among 666 upper-extremity injuries in children, and in developing prediction rules for selective radiographic assessment. Fracture estimates and error reductions provided by RPA and LA were very similar. Each technique generated a set of prediction rules with a range of misclassification probabilities, and evaluated the probabilities of fracture for all observation patterns. LA used more information than RPA in observation pattern evaluations, however, and provided fracture estimates specific to each pattern. With currently available statistical software, RPA output provides better statistical guidance in generating prediction rules, whereas LA provides more statistical information of use in evaluating observation patterns. LA warrants attention similar to that conferred on RPA. It appears that complementary use of LA and RPA would be valuable in developing clinical guidelines.

Immunization opportunities missed among urban poor children

Low immunization rates among US preschool children suggest a need for improved immunization practices. Immunization and encounter records were reviewed to ascertain immunization rates and missed opportunities for vaccine administration among 515 preschool children who were active patients at a hospital-based primary care center serving lower socioeconomic status families in Rochester, NY. The point prevalence at a mean age of 4.4 years for lack of one or more recommended immunizations was 27%; 7% were missing measles-mumps-rubella, 18% were missing Haemophilus influenzae type b, 8% were missing two or more diphtheria-tetanus-pertussis, and 4% were missing two or more oral poliovirus immunizations. A visit was counted as a missed opportunity if an immunization was due but not given. Over the period from birth through age 36 months, 422 (82%) of children missed at least one immunization opportunity. For these 422 children, there was a mean of 7.2 missed opportunities per child. Although 64% of missed opportunities occurred at an acute illness visit, 36% occurred at well-child, administrative, follow-up, or chronic illness visits. Review of 200 medical records randomly selected from all opportunities at acute illness visits found no contraindication in 63% (50% nonfebrile infectious disease, 13% minor noninfectious problems). Findings for random samples of 100 missed diphtheria-tetanus-pertussis opportunities for children aged 2 to 6 months and 100 missed measles-mumps-rubella opportunities for children 15 to 24 months were similar to findings for the sample of all acute illness visits. Emergency department visits, where immunization records were not readily available, accounted for 18% of missed opportunities.(ABSTRACT TRUNCATED AT 250 WORDS)

Occurrence of groups A and B of respiratory syncytial virus over 15 years: associated epidemiologic and clinical characteristics in hospitalized and ambulatory children

Over 15 years respiratory syncytial virus (RSV) isolates from 1209 hospitalized and ambulatory children were examined for strain group and in a subset for subgroup to determine the associated epidemiologic and clinical characteristics. Three patterns of yearly outbreaks existed: (1) strong predominance of group A strains (9 years with 83%-100% A strains), (2) relatively equal proportions of group A and B strains (4 years), and (3) strong predominance of group B strains (78%-85%) in 2 years, separated by a decade. The first pattern of highly dominant A strains occurred in cycles of 1 or 2 consecutive years with a single intervening year in which B strains were greater than or equal to 40% of the isolates. Subgroups A1 and A2 predominated, while B2, 3, and 4 occurred almost equally. A greater clinical severity for Group A strains was suggested by children with group A infections requiring intensive care significantly more often (15.4 vs. 8.3%, P = .008). Further, strongly dominant A strain years were associated with higher proportions of RSV admissions requiring intensive care (16.6% vs. 5.5%, P less than .01). Strains of subgroups A2 and B4 were more frequently found in hospitalized patients and A1 in outpatients, and the 2 years with the highest rates of intensive care admissions were those in which subgroup A2 dominated.

Prediction rules for selective radiographic assessment of extremity injuries in children and adolescents

To assess the potential for selective use of roentgenography in evaluating extremity injuries, prediction rules were developed based on prospective observations for 617 injured children and adolescents examined in our Emergency Department (phase 1) and tested on 601 examined 1 year later (phase 2). Logit analysis produced best-fitting statistical models for phase 1 data with significant (P less than 0.05) direct effects of gross signs, point tenderness, activity not routine, swelling moderate or severe, time from injury less than 6 hours, and pain with motion for upper extremity injuries; and, for lower extremity injuries, not knee injury, activity not routine, point tenderness, and foot injury. Prediction rules developed in phase 1 performed equally well when tested on phase 2 injuries. Data from both phases were combined, therefore, in analysis that produced risk estimates. For all injury types (ie, for injuries with all possible combinations of presence or absence of these findings), risk for fracture was derived. For upper extremity injuries, with a threshold risk for fracture of 20% used to select specific injury types for roentgenography, prediction rule outcomes were 18.1% of roentgenograms avoided and 5.3% of fractures missed. For lower extremity injuries, using a threshold risk of 10% to select injury types for roentgenography, outcomes were 25.8% of roentgenograms avoided and 5.3% of fractures missed. Alternative prediction rules allowed still greater roentgenogram avoidance, although missed fractures also increased. Risk of adverse functional outcome from missed fractures appeared small. Annual national cost savings from the elimination of 18.1% of upper and 25.8% of lower extremity roentgenographic evaluations was estimated at $103 million.

Variation in severity of respiratory syncytial virus infections with subtype

Two major subtypes of respiratory syncytial virus have been identified. This study assessed the hypothesis that A-subtype infections were more severe than B-subtype infections among the 157 infants hospitalized in two hospitals in Rochester, N.Y., during two winters. Severity was measured both by specific clinical observations and by a severity index that was derived empirically. Among all subjects, several clinical observations suggested that A-subtype infections were more severe. For example, mechanical ventilation was required in 12.6% of those with A-subtype compared with 1.6% of those with B-subtype infection (relative risk = 7.88; p = 0.01). Among high-risk infants (infants with underlying conditions or age 3 months or less at admission), carbon dioxide tension greater than 45 mm Hg was found in 37.0% of those with A-subtype compared with 12.0% of those with B-subtype infection (relative risk = 3.08; p = 0.04). In discrete multivariate (logit) analysis, effects of subtype (odds ratio = 6.59; p less than 0.01) on severity remained after adjustment for other statistically significant effects of age less than 3 months, underlying condition, and premature birth. The finding that A-subtype infections were more severe might have important implications for vaccine development, studies of the virulence of respiratory syncytial virus, clinical management (e.g., selection for antiviral therapy), and long-term prognosis.

Wheezing at 8 and 13 years: changing importance of bronchiolitis and passive smoking

A group of 153 children (51 with a history of bronchiolitis and 102 matched controls) were evaluated in a historical cohort study at a mean age of 8 years and again at 13 years to test the primary hypothesis that mild bronchiolitis, far more common than severe (hospitalized) bronchiolitis, predicts wheezing. A secondary hypothesis was that passive smoking also predicts wheezing. Many potentially confounding variables such as family history of asthma were controlled in analyses. Analysis at 13 years produced results that were not anticipated from previous analysis of interviews at age 8. Although mild bronchiolitis was a powerful predictor of wheezing at age 8 years, it was no longer a strong predictor of wheezing at age 13 in either bivariate or multivariate analysis. Although epidemiologic studies, by their nature, cannot prove causality, findings are consistent with the hypothesis that sequelae often follow mild bronchiolitis but diminish during childhood. Maternal smoking was a powerful predictor of wheezing at age 13 in bivariate analysis (Kendall's Tau B = 0.19, P less than 0.01) and in multivariate analysis (odds ratio = 2.67, P less than 0.01). In children at highest risk for wheezing, males with a family history of asthma, multivariate analysis suggested that maternal smoking is associated with an increase in wheezing from 36% to 60%. We conclude that passive smoking, previously identified as a risk factor in this population for both bronchiolitis in infancy and wheezing at age 8, is a risk factor for wheezing-associated morbidity throughout the childhood years.

Lower respiratory tract illness in the first two years of life: epidemiologic patterns and costs in a suburban pediatric practice

The epidemiologic patterns and the economic impact of acute lower respiratory tract illness (LRTI) in children under age two were studied using data collected from November 1, 1971-August 30, 1975 in a suburban pediatric practice in Monroe County, New York. LRTI was responsible for 23 illness episodes per 100 child-years among children in their first two years of life. This indicates that a cohort of 100 children might be anticipated to have 46 LRTI episodes from birth until their second birthday. The majority of episodes correlated with the presence of four viruses in the community, most commonly respiratory syncytial virus. The minimal, estimated direct cost of LRTI in the first two years of life based on 1984 cost data was equivalent to $35.14 for every child and was comprised of hospitalization cost ($19.68) and ambulatory care cost ($15.46). Hospitalization costs attributable to LRTI comprised at least 2.5 per cent of all hospitalization costs in this age group. Immunization against the four most common respiratory viruses, at a reasonable cost per child immunized, would appear to be cost beneficial.

Breast feeding and maternal smoking as predictors of wheezing in children age 6 to 10 years

The possibility that controllable environmental factors such as passive smoking and non-breast feeding contribute substantially to wheezing has implications for prevention. Effects of passive smoking and non-breast feeding on wheezing in children aged 6 to 10 years were explored in a historical cohort study of 223 children. Family history of respiratory allergy or asthma, male sex, maternal smoking, and non-breast feeding were significantly associated (p less than 0.05) with wheezing in bivariate analysis. In multivariate loglinear analyses, predictors of wheezing included non-breast feeding (p = 0.05, odds ration = 2.1), male sex (p less than 0.03, odds ratio = 3.1), and family history of respiratory allergy (p less than 0.03, odds ratio = 2.6). In a second model, predictors included an interaction of maternal smoking and family history (p less than 0.005, odds ratio = 4.6) in addition to male sex and family history of respiratory allergy. In further exploration based on tabular analysis, maternal smoking appeared to increase wheezing among children in whom the family history of respiratory allergy was positive (p less than 0.001). Among children in whom the family history of respiratory allergy was negative, non-breast feeding appeared to increase wheezing (p = 0.01). Promotion of breast feeding and reduction of maternal smoking might reduce childhood wheezing.

Parental smoking, presence of older siblings, and family history of asthma increase risk of bronchiolitis

Bronchiolitis is a common lower respiratory tract illness in infants and has substantial acute morbidity and sequelae. To identify risk factors for bronchiolitis, a case-control study was conducted in which 53 subjects who had bronchiolitis were matched with two controls who had no bronchiolitis in infancy. In multivariate analysis, direct effects of passive smoking and older siblings achieved statistical significance. Family history of asthma appeared to interact with older siblings. Among subjects without a family history of asthma, statistically significant predictors proved to be older siblings (odds ratio, 2.31) and passive smoking (odds ratio, 3.87). Among subjects with a family history of asthma, older siblings proved to be an even stronger predictor (odds ratio, 46.81), while the odds ratio for passive smoking did not change much (odds ratio, 4.03). The combined presence of older siblings and passive smoking yielded an odds ratio of 8.94 among subjects without a family history of asthma and 181.67 among subjects with a family history of asthma. Analysis provided risk estimates that were particularly high for certain groups. Among infants with a family history of asthma, 49% who have an older sibling may develop bronchiolitis. If they are also exposed to cigarette smoke, almost 80% may develop bronchiolitis. Among infants without a family history of asthma, bronchiolitis may develop in 46% of infants if there is both an older sibling and exposure to smoke. Exposure of infants to cigarette smoke might diminish more rapidly if clinicians and parents were aware of such high risks. Efforts to reduce morbidity from bronchiolitis in infants might best be directed at the reduction of smoking in families with previous children, particularly if there is a family history of asthma, and at methods that protect infants from respiratory virus carried by siblings.

Airway hyperreactivity and a history of clinical manifestations of asthma in childhood

The relationship between airway hyperreactivity and a history of the clinical manifestations of asthma was investigated in 54 children between the ages of 8 and 12. Airway reactivity was assessed by measuring the change in pulmonary function following the hyperventilation of subfreezing air. Clinical manifestations of asthma were assessed by a standardized questionnaire regarding lower respiratory symptoms and by medical records review. The subjects were participating in a study of the sequelae of bronchiolitis; 25 had seen a physician for mild bronchiolitis during the first 2 years of life, and the remainder had not. Airway hyperreactivity was demonstrated in 8 of the 54 children and correlated with use of medication for asthma in the 2 years before pulmonary testing and positive parental response to the question, "Does your child wheeze apart from colds?" Airway hyperreactivity did not correlate with a history of other respiratory symptoms or with a history of physician-diagnosed wheezing or asthma. No questionnaire or chart review item identified over 50% of the children with reactive airways, and most subjects identified by each of the items did not demonstrate hyperreactive airways. These data suggest that airway reactivity is only weakly associated with a history of the clinical manifestations of asthma in childhood, in part because children with clinically inactive asthma do not consistently demonstrate airway hyperreactivity and in part because many children with hyperreactive airways have never had respiratory symptoms.

Normal pulmonary function measurements and airway reactivity in childhood after mild bronchiolitis

Concern about the long-term sequelae of bronchiolitis has been raised through studies of children hospitalized for bronchiolitis, but the long-term sequelae of mild bronchiolitis have not been studied. We assessed the hypothesis that 25 children with mild bronchiolitis (index subjects) were at greater risk for abnormalities of pulmonary function or airway reactivity to cold air between the ages of 8 and 12 years than were randomly selected, matched controls. There were no consistent differences in pulmonary function or airway reactivity between index and control groups. Airway hyperreactivity was found in five control subjects and three index subjects, and all children with symptomatic asthma were identified by cold air challenge. Our data suggest that children with a history of mild bronchiolitis are not at increased risk between ages 8 and 12 years for airway hyperreactivity or for abnormalities in pulmonary function.

Predicting clinically significant lower respiratory tract illness in childhood following mild bronchiolitis

A historical cohort study was conducted to measure lower respiratory tract illness (LRTI) up to nine years following mild bronchiolitis and to discover attributes that predict an increased risk for LRTI in childhood. The hypothesis assessed was that the occurrence of bronchiolitis predicts LRTI following the second birthday (childhood LRTI) after adjusting for potentially confounding variables such as a family history of respiratory allergy. Fifty-three children (index subjects) who were seen for bronchiolitis at a suburban community pediatric practice were compared on the basis of childhood LRTI with a control group of 159 children. Chart review, when children were a mean of 8 years old, determined the frequency of childhood LRTI. The mean frequency of childhood LRTI was greater in index subjects than in control subjects (1.62 vs 0.98). This difference remained after adjusting for potentially confounding variables. The yearly occurrence of any LRTI was significantly more common in index subjects through the third year of life (38% vs 15%). A tendency for a more common occurrence of any LRTI was noted through the fifth year (25% vs 16%), but not thereafter. Further analysis of index subjects disclosed that only those who experienced a subsequent LRTI before the second birthday were at an increased risk for the development of childhood LRTI.

Bronchiolitis as a possible cause of wheezing in childhood: new evidence

A historical cohort study was performed in order to assess the hypothesis that even mild bronchiolitis in infancy in a predictor of wheezing later in childhood. Subjects who had experienced bronchiolitis and a matched control group were compared in terms of reported wheezing 8 years later. A highly significant difference was found between the bronchiolitis group and the control group in terms of current wheezing (P less than .0001, relative risk 3.24). This difference was maintained after adjusting for many potentially confounding variables including family history of allergy and other allergic manifestations in the child. Results suggested that 13.6% of a normal practice population in the age range 6 to 9 years currently wheeze, but that 44.1% of children who experienced bronchiolitis currently wheeze. Based on the incidence of bronchiolitis (4.27/100 children in their first 2 years of life) and the relative odds for wheezing derived from a logistic regression model including variables that measured passive smoking, genetic tendency to wheeze, and bronchiolitis, calculations of attributable risk suggested that wheezing in 9.4% of the population of children who currently wheeze was attributable to bronchiolitis.