Healthcare Providers' and Pregnant People's Preferences for a Preventive to Protect Infants from Serious Illness Due to Respiratory Syncytial Virus

We assessed the impact of respiratory syncytial virus (RSV) preventive characteristics on the intentions of pregnant people and healthcare providers (HCPs) to protect infants with a maternal vaccine or monoclonal antibodies (mAbs). Pregnant people and HCPs who treated pregnant people and/or infants were recruited via convenience sample from a general research panel to complete a cross-sectional, web-based survey, including a discrete choice experiment (DCE) wherein respondents chose between hypothetical RSV preventive profiles varying on five attributes (effectiveness, preventive type [maternal vaccine vs. mAb], injection recipient/timing, type of medical visit required to receive the injection, and duration of protection during RSV season) and a no-preventive option. A best-worst scaling (BWS) exercise was included to explore the impact of additional attributes on preventive preferences. Data were collected between October and November 2022. Attribute-level preference weights and relative importance (RI) were estimated. Overall, 992 pregnant people and 310 HCPs participated. A preventive (vs. none) was chosen 89.2% (pregnant people) and 96.0% (HCPs) of the time (DCE). Effectiveness was most important to preventive choice for pregnant people (RI = 48.0%) and HCPs (RI = 41.7%); all else equal, pregnant people (RI = 5.5%) and HCPs (RI = 7.2%) preferred the maternal vaccine over mAbs, although preventive type had limited influence on choice. Longer protection, protection starting at birth or the beginning of RSV season, and use for both pre-term and full-term babies were ranked highest in importance (BWS). Pregnant people and HCPs strongly preferred a preventive to protect infants against RSV (vs. none), underscoring the need to incorporate RSV preventives into routine care.

Long-Term effects of COVID-19: a review of current perspectives and mechanistic insights

Although SARS-CoV-2, responsible for COVID-19, is primarily a respiratory infection, a broad spectrum of cardiac, pulmonary, neurologic, and metabolic complications can occur. More than 50 long-term symptoms of COVID-19 have been described, and as many as 80% of patients may develop ≥1 long-term symptom. To summarize current perspectives of long-term sequelae of COVID-19, we conducted a PubMed search describing the long-term cardiovascular, pulmonary, gastrointestinal, and neurologic effects post-SARS-CoV-2 infection and mechanistic insights and risk factors for the above-mentioned sequelae. Emerging risk factors of long-term sequelae include older age (≥65 years), female sex, Black or Asian race, Hispanic ethnicity, and presence of comorbidities. There is an urgent need to better understand ongoing effects of COVID-19. Prospective studies evaluating long-term effects of COVID-19 in all body systems and patient groups will facilitate appropriate management and assess burden of care. Clinicians should ensure patients are followed up and managed appropriately, especially those in at-risk groups. Healthcare systems worldwide need to develop approaches to follow-up and support patients recovering from COVID-19. Surveillance programs can enhance prevention and treatment efforts for those most vulnerable.

Impact of including productivity costs in economic analyses of vaccines for C. difficile infections and infant respiratory syncytial virus, in a UK setting

OBJECTIVES

It has been estimated that vaccines can accrue a relatively large part of their value from patient and carer productivity. Yet, productivity value is not commonly or consistently considered in health economic evaluations of vaccines in several high-income countries. To contribute to a better understanding of the potential impact of including productivity value on the expected cost-effectiveness of vaccination, we illustrate the extent to which the incremental costs would change with and without productivity value incorporated.

METHODS

For two vaccines currently under development, one against Cloistridioides difficile (C. difficile) infection and one against respiratory syncytial disease (RSV), we estimated their incremental costs with and without productivity value included and compared the results.

RESULTS

In this analysis, reflecting a UK context, a C. difficile vaccination programme would prevent £12.3 in productivity costs for every person vaccinated. An RSV vaccination programme would prevent £49 in productivity costs for every vaccinated person.

CONCLUSIONS

Considering productivity costs in future cost-effectiveness analyses of vaccines for C. difficile and RSV will contribute to better-informed reimbursement decisions from a societal perspective.

Maternal Tdap and influenza vaccination uptake 2017-2021 in the United States: Implications for maternal RSV vaccine uptake in the future

BACKGROUND

Assessment of maternal vaccine coverage is important for understanding and quantifying the impact of currently recommended vaccines as well as modeling the potential impact of future vaccines. However, existing data lack detail regarding uptake according to week of gestational age (wGA). Such granularity is valuable for more accurate estimation of vaccine impact.

OBJECTIVE

To summarize contemporary maternal Tdap vaccination uptake, overall, yearly, and by wGA, and maternal influenza vaccination uptake, overall, by influenza observation year, immunization month, and delivery month, in the US.

METHODS

Female patients 18-49 years of age with a pregnancy resulting in a live born infant (i.e., delivery) between 2017 and 2021 were selected from the Optum electronic health records (EHRs) database. Recently published gestational age algorithms were utilized to estimate wGA.

RESULTS

Of 1,021,260 deliveries among 886,660 women between 2017-2021, 55.1% had Tdap vaccination during pregnancy; vaccine coverage varied slightly by year (2017: 56.6%; 2018: 55.2%; 2019: 55.2%; 2020: 54.7%; 2021: 52.1%). Most (64.4%) maternal Tdap vaccinations occurred 27-32 wGA; 79.5% occurred during the entire 10-week recommended vaccination window (27-36 wGA). In the evaluation of influenza vaccination uptake (n=798,113 deliveries; 714,841 women), 33.5% of deliveries had influenza vaccination during influenza observation years 2017-2021, most (73.0%) of which occurred during influenza peak activity months (October-January) with approximately one-quarter (27.0%) of vaccinations having occurred during the off-peak months, mostly in September.

CONCLUSIONS

In this large contemporary analysis of EHR data, uptake of Tdap vaccination during pregnancy was consistent with previously published estimates; notably, most vaccination occurred early in the recommended 27-36 wGA window. Maternal influenza vaccination uptake largely correlated with peak influenza activity months and not gestational age. These study findings may have important implications for estimating the potential uptake and impact of future maternal vaccines.

106. High Maternal Tdap Vaccine Uptake During Early Part of Vaccination Window: Implications for Future Maternal Vaccines

Background

Maternal vaccines to prevent respiratory syncytial virus (RSV) among infants are in development. Uptake of existing maternal vaccines can be used to predict uptake of future maternal RSV vaccines and may be used to inform vaccine policy decisions. Previous reports of maternal vaccination rates do not estimate vaccine uptake by gestational week (wGA) of pregnancy, which is needed for precise estimation of vaccine impact. This study estimated the uptake of maternal Tdap vaccination overall and by wGA in a large electronic health records (EHR) database representing both privately and publicly insured patients over a recent 5-year period.

Methods

We identified pregnant women aged 15 – 44 years who had a live birth delivery between 01/01/2017 – 9/29/2021 in the Optum EHR database. Continuous activity for 6 months pre-conception through 1 day after delivery were required. Patients with >1 type of pregnancy outcome within 7 days and/or unidentifiable wGA were excluded. We utilized recently published gestational age algorithms to estimate the uptake of maternal Tdap vaccination overall and by wGA of pregnancy. Results were reported by year.

Results

The population included 1,056,488 live births among 919,510 pregnant women during the study period. The average age at delivery was 29.7 years (SD: 5.6), 72% were white, 82% were non-Hispanic; 58% had private insurance, and 38% had Medicaid. Overall, 56% of the pregnancies included a Tdap vaccine during their pregnancy. Among vaccinated pregnancies, the majority (68%) of Tdap vaccines were administered during the first 6 weeks of the recommended 10-week vaccination window (CDC recommends Tdap vaccination from 27-36 wGA) (Table). Table.

2207. Rates of Lower Respiratory Tract Infections Among US Adults Aged ≥18 Years With and Without Chronic Medical Conditions

Background

While it is widely recognized that older adults and adults with chronic medical conditions are at increased risk of lower respiratory tract infections (LRTI), available evidence on the magnitude of increased risk is limited.

Methods

A retrospective observational cohort study using IBM MarketScan Commercial/Medicare Databases (2016–2019) was conducted. The study population included all adults (age ≥ 18 years) and was stratified by age and comorbidity profile (with vs. without high-risk conditions, based on recommendations for influenza vaccination in the United States). LRTI was ascertained on an overall basis as well as by causative pathogen (e.g., respiratory syncytial virus [RSV]) based on corresponding diagnosis codes, and was classified based on care setting (hospital, emergency department [ED], physician office/hospital outpatient [PO/HO]). Incidence rates (and relative rates [RRs]) were generated by age, and within each age group, by comorbidity profile.

Results

Using adults aged 18-34 years as the reference, RR of LRTI generally increased with older age across care settings, with the most marked increase for hospitalizations: for hospitalized-LRTI, RRs ranged from 1.7 for 35-49 years to 78.9 for ≥ 85 years; for ED-LRTI and PO/HO-LRTI, RRs ranged from 1.0 to 3.4 and from 1.4 to 2.1, respectively (Table). Within age groups, LRTI rates were also consistently higher among adults with versus without high-risk conditions: for hospitalized-LRTI, RRs ranged from 9.9 to 21.1; for ED-LRTI, from 2.3 to 3.2; and for PO/HO-LRTI, from 1.6 to 2.5. Age-specific RRs of hospitalized-LRTI due to RSV were largely comparable to overall LRTI results; age-specific RRs for other care settings, and RRs for adults with versus without high-risk conditions across care settings, were generally higher for LRTI due to RSV.

Conclusion

LRTI incidence, especially for events requiring acute inpatient care, is markedly higher among older adults and adults of all ages with chronic medical conditions. Effective vaccines against respiratory pathogens could help reduce this elevated risk of LRTI.

Disclosures

Derek Weycker, Ph.D., Pfizer Inc.: Grant/Research Support Ahuva Averin, M.P.P., Pfizer Inc.: Grant/Research Support Linnea Houde, M.S., Pfizer Inc.: Grant/Research Support Kevin Ottino, M.H.S., Pfizer Inc.: Grant/Research Support Kimberly M. Shea, Ph.D., M.P.H., Pfizer: Employee|Pfizer: Stocks/Bonds Bradford J. Gessner, M.D., M.P.H., Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds Kari Yacisin, M.D., Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds Daniel Curcio, M.Sc., Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds Elizabeth Begier, M.D., M.P.H., Pfizer: Employee|Pfizer: Stocks/Bonds Mark Rozenbaum, Ph.D., M.B.A., Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds.

Health outcomes and economic burden of hospitalized COVID-19 patients in the United States

OBJECTIVE

The aims of this study were to evaluate health outcomes and the economic burden of hospitalized COVID-19 patients in the United States.

METHODS

Hospitalized patients with a primary or secondary discharge diagnosis code for COVID-19 (ICD-10 code U07.1) from 1 April to 31 October 2020 were identified in the Premier Healthcare COVID-19 Database. Patient demographics, hospitalization characteristics, and concomitant medical conditions were assessed. Hospital length of stay (LOS), in-hospital mortality, hospital charges, and hospital costs were evaluated overall and stratified by age groups, insurance types, and 4 COVID-19 disease progression states based on intensive care unit (ICU) and invasive mechanical ventilation (IMV) usage.

RESULTS

Of the 173,942 hospitalized COVID-19 patients, the median age was 63 years, 51.0% were male, and 48.5% were covered by Medicare. The most prevalent concomitant medical conditions were cardiovascular disease (73.5%), hypertension (64.8%), diabetes (40.7%), obesity (27.0%), and chronic kidney disease (24.2%). Approximately one-fifth (21.9%) of the hospitalized COVID-19 patients were admitted to the ICU and 16.9% received IMV; most patients (73.6%) did not require ICU admission or IMV, and 12.4% required both. The median hospital LOS was 5 days, in-hospital mortality was 13.6%, median hospital charges were $43,986, and median hospital costs were $12,046. Hospital LOS and in-hospital mortality increased with ICU and/or IMV usage and age; hospital charges and costs increased with ICU and/or IMV usage. Patients with both ICU and IMV usage had the longest median hospital LOS (15 days), highest in-hospital mortality (53.8%), and highest hospital charges ($198,394) and hospital costs ($54,402).

LIMITATIONS

This retrospective administrative database analysis relied on coding accuracy and a subset of admissions with validated/reconciled hospital costs.

CONCLUSIONS

This study summarizes the severe health outcomes and substantial hospital costs of hospitalized COVID-19 patients in the US. The findings support the urgent need for rapid implementation of effective interventions, including safe and efficacious vaccines.

Weekly dengue forecasts in Iquitos, Peru; San Juan, Puerto Rico; and Singapore

BACKGROUND

Predictive models can serve as early warning systems and can be used to forecast future risk of various infectious diseases. Conventionally, regression and time series models are used to forecast dengue incidence, using dengue surveillance (e.g., case counts) and weather data. However, these models may be limited in terms of model assumptions and the number of predictors that can be included. Machine learning (ML) methods are designed to work with a large number of predictors and thus offer an appealing alternative. Here, we compared the performance of ML algorithms with that of regression models in predicting dengue cases and outbreaks from 4 to up to 12 weeks in advance. Many countries lack sufficient health surveillance infrastructure, as such we evaluated the contribution of dengue surveillance and weather data on the predictive power of these models.

METHODS

We developed ML, regression, and time series models to forecast weekly dengue case counts and outbreaks in Iquitos, Peru; San Juan, Puerto Rico; and Singapore from 1990-2016. Forecasts were generated using available weekly dengue surveillance, and weather data. We evaluated the agreement between model forecasts and actual dengue observations using Mean Absolute Error and Matthew's Correlation Coefficient (MCC).

RESULTS

For near term predictions of weekly case counts and when using surveillance data, ML models had 21% and 33% less error than regression and time series models respectively. However, using weather data only, ML models did not demonstrate a practical advantage. When forecasting weekly dengue outbreaks 12 weeks in advance, ML models achieved a maximum MCC of 0.61.

CONCLUSIONS

Our results identified 2 scenarios when ML models are advantageous over regression model: 1) predicting dengue weekly case counts 4 weeks ahead when dengue surveillance data are available and 2) predicting weekly dengue outbreaks 12 weeks ahead when dengue surveillance data are unavailable. Given the advantages of ML models, dengue early warning systems may be improved by the inclusion of these models.

Decline in Pneumococcal Disease Attenuated in Older Adults and Those With Comorbidities Following Universal Childhood PCV13 Immunization

Background

Following introduction of 7-valent pneumococcal conjugate vaccine (PCV7) in the United States, epidemiology of pneumococcal disease shifted such that disease incidence in the elderly exceeded that in children. We evaluated the impact of replacing PCV7 with PCV13 on disease burden in adults and identified age/risk-specific subgroups with the highest remaining disease burden.

Methods

A retrospective design and data from two US healthcare claims repositories were used. Study population included adults aged ≥18 years and was stratified by age (18–49, 50–64, 65–74, ≥75) and risk profile (healthy, at-risk, high-risk). Rate ratios comparing invasive pneumococcal disease (IPD), all-cause hospitalized pneumonia (ACHP), and pneumococcal pneumonia requiring hospitalization among at-risk and high-risk adults vs healthy counterparts were estimated for 2007–2010 (pre-PCV13), 2011–2012 (peri-PCV13), and 2013–2015 (post-PCV13).

Results

Across study periods, IPD and ACHP rates increased with age (2–27 times higher in persons ≥75 vs 18–49) and comorbidity (4–20 times higher in high-risk vs healthy). From pre- to post-PCV13 period, IPD rates declined 5%–48% and ACHP rates declined 4%–19% across age and risk groups (ACHP did not decline in persons ≥75). Decline in IPD and ACHP was attenuated among older adults and those with comorbidities. Accordingly, rate ratios among at-risk and high-risk persons (vs healthy counterparts) increased during the peri- and post-PCV13 periods compared with the pre-PCV13 period.

Conclusions

The switch to PCV13 was associated with large declines in pneumococcal disease among US adults. However, the decline was attenuated with increasing age (and, for ACHP, was absent in persons ≥75) and in those with comorbidities.

Characteristics of Serotype 3 Invasive Pneumococcal Disease before and after Universal Childhood Immunization with PCV13 in Massachusetts

BACKGROUND

Although a substantial decline in vaccine-serotype invasive pneumococcal disease (IPD) incidence was observed following the introduction of pneumococcal conjugate vaccines (PCV), the estimated range of thirteen-valent conjugate vaccine (PCV13) effectiveness for serotype 3 disease is wide and includes zero. We assessed the impact of PCV13 on serotype 3 IPD incidence and disease characteristics in Massachusetts' children.

METHODS

Serotype 3 IPD cases in children <18 years old were identified via enhanced passive surveillance system in Massachusetts. We compared incidence rates and characteristics of IPD cases before and after PCV13.

RESULTS

A total of 47 serotype 3 IPD cases were identified from 2002 to 2017; incidence of serotype 3 IPD in the years following PCV13 was 0.19 per 100,000 children compared to 0.21 before PCV 13, incidence rate ratio (IRR) = 0.86 (95% CI 0.47-1.57). The majority (78%) of post-PCV13 serotype 3 IPD cases occurred among fully vaccinated children. Age distribution, clinical syndrome and presence of comorbidities among serotype 3 IPD cases were similar before and after PCV13 introduction. There was no association between the date of the last PCV13 dose and time to IPD to suggest waning of immunity.

CONCLUSIONS

seven years following PCV 13 we found no significant changes in serotype 3 IPD incidence or disease characteristics in children in Massachusetts.

Pneumonia in young adults with asthma: impact on subsequent asthma exacerbations

Background: Recent studies of community-acquired pneumonia (CAP) have recognized acute cardiac complications-such as myocardial infarction, arrhythmia, or congestive heart failure (CHF)-as frequent complications during the acute process. As well, a prolonged vulnerability to exacerbations of underlying comorbidities-such as CHF and COPD-has been observed following CAP. We hypothesized that young adults with underlying asthma could also be adversely impacted over a prolonged time period following CAP.Methods: Using a retrospective matched-cohort design and data from a US private healthcare claims repository (>15 M persons annually), we selected all adults 18-49 years of age with evidence of asthma as their only comorbidity for inclusion in the source population. Then, from the source population, we matched one comparison patient to each CAP patient based on index date, age, sex, and selected markers for health status (eg, history of asthma-related healthcare encounters), and evaluated subsequent outpatient and inpatient encounters for asthma exacerbations.Results: Asthma exacerbations were identified twice as often in the 12 months subsequent to acute CAP. Cumulative incidence proportions for asthma exacerbations requiring hospitalization or emergency department care after 12 months of follow-up were 19.9% for those previously hospitalized with CAP versus 9.0% for matched comparison patients (difference, 10.9%; p<0.001), and were 12.4% for non-hospitalized CAP patients versus 7.7% for matched counterparts (difference, 4.7%; p<0.001).Conclusion: Our analysis provides further evidence that acute CAP has a prolonged impact on respiratory health.

1430. Evolving Impact of 13-Valent Pneumococcal Conjugate Vaccine on Invasive Pneumococcal Disease

Background

The 13-valent pneumococcal conjugate vaccine (PCV13) replaced PCV7 in the childhood immunization schedule in Massachusetts (MA) beginning in April, 2010. We describe the current epidemiology of invasive pneumococcal disease (IPD) in Massachusetts (MA) children after introduction of PCV13.

Methods

Cases of invasive pneumococcal disease (IPD) in children <18 years of age were detected through an enhanced surveillance system in MA since 2001. All cases in children and Streptococcus pneumoniae (SP) isolates, when available, are submitted to Department of Public Health (MDPH) and parents/physicians are interviewed for confirmation of demographic and clinical data. All available isolates are confirmed as SP, serotyped by Quellung reaction.

Results

There were 351 IPD cases in MA children from April 1, 2010 to September 31, 2017, and 36 (10.3%) were in infants <6 months; 42 (12.0%) in children between 6 and 12 months; 63 (18.0%) in toddlers 12–24 months; 102 (29.1%) in children aged 2–5 years, and 108 (30.8%) were in children aged ≥5 years. Incidence of IPD declined to 6.8/10⁵ children (95% CI 2.6–11.1) in 2015/2016 period which represents a 72.1% decline compared with 2010/2011 (24.4/10⁵, 95% CI 16.3–32.5) (figure). However, in 2016/2017, IPD incidence increased to 10.4/10⁵ children (95% CI 5.2–15.7). The most common clinical presentation was bacteremia (62.9%), followed by pneumonia (30.5%) and CNS disease (6.6%). Among, 103 (32.6%) children with ≥1 comorbidity, asthma (13.2%), hematologic malignancy (12.1%), prematurity (9.9%) and sickle cell disease (9.9%) were the most common comorbidities. He overall mortality rate was 5.1%. Isolates from 308 (89.3%) were available for serotyping; vaccine serotypes (VST) were identified in 106 (33.3%) IPD cases [19A (46.2%), 7F (19.9%), 3 (17.9%), 19F (10.4%), 6A (2.8%), 14, 18C, 5 (0.9% each). Serotypes 15BC (13.7%), 22F (12.6%) and 33F (11.8%) were the most common nonvaccine serotypes (NVST).

Conclusion

Invasive pneumococcal disease identified in the post-PCV13-era is primarily caused by NVSTs, specifically serotypes 15BC, 33F and 22F; and disproportionately observed in children with comorbid conditions. Continued surveillance is necessary to determine the impact of PCV13, as well as track potential changes in disease incidence and character due to NVST.

Disclosures

All authors: No reported disclosures.

Ten-year trends in intensive care admissions for respiratory infections in the elderly

BACKGROUND

The consequences of the ageing population concerning ICU hospitalisation need to be adequately described. We believe that this discussion should be disease specific. A focus on respiratory infections is of particular interest, because it is strongly associated with old age. Our objective was to assess trends in demographics over a decade among elderly patients admitted to the ICU for acute respiratory infections.

METHODS

A cross-sectional study was performed between 2006 and 2015 based on hospital discharge databases in one French region (2.5 million inhabitants). Patients with acute respiratory infection were selected according to the specific ICD-10 diagnosis codes recorded, including acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and community-acquired pneumonia (CAP). We also identified comorbid conditions based on any significant ICD-10 secondary diagnoses adapted from the Charlson and Elixhauser indexes.

RESULTS

A total of 98,381 hospital stays for acute respiratory infection were identified among the 3,856,785 stays over the 10-year period. The number of patients 75 y/o and younger increased 1.6-fold from 2006 to 2015, whereas the numbers of patients aged 85-89 and ≥ 90 y/o increased by 2.5- and 2.1-fold, respectively. Both CAP and AECOPD hospitalisations significantly increased for all age groups over the decade. ICU hospitalisations for respiratory infection increased 2.7-fold from 2006 to 2015 (p = 0.0002). The greatest increases in the use of ICU resources were for the 85-89 and ≥ 90 y/o groups, which corresponded to increases of 3.3- and 5.8-fold. Indeed, the proportion of patients hospitalized for respiratory infection in ICU that were elderly clearly grew during the decade: 11.3% were ≥ 85 y/o in 2006 versus 16.4% in 2015 (p < 0.0001). This increase in ICU hospitalisation rate of ageing patients was not associated with significant changes in the level of care or ICU mortality except for patients ≥ 90 y/o (for whom ICU mortality dropped from 40.9 to 22.3%, p = 0.03).

CONCLUSION

We observed a substantial increase in acute respiratory infection diagnoses associated with hospitalisation between 2006 and 2015, with a growing demand for critical care services. Both the absolute number and the percentage of elderly patient ICU admissions increased over the last decade, with the greatest increases being observed for patients 85 years and older.

Risk of exacerbation following pneumonia in adults with heart failure or chronic obstructive pulmonary disease

BACKGROUND

Recent evidence demonstrates increased short-term risk of cardiac complications and respiratory failure among patients with heart failure (HF) and chronic obstructive pulmonary disease (COPD), respectively, concurrent with an episode of community-acquired pneumonia (CAP). We evaluated patients with pre-existing HF or COPD, beginning 30 days after CAP diagnosis, to determine if CAP had a prolonged impact on their underlying comorbidity.

METHODS

A retrospective matched-cohort design using US healthcare claims was employed. In each month of accrual, patients with HF or COPD who developed CAP ("CAP patients") were matched (1:1, without replacement, on demographic and clinical profiles) to patients with HF or COPD who did not develop CAP ("comparison patients"). All patients were aged ≥40 years, and were pneumonia free during prior 1-year period. Exacerbation beginning 30 days after the CAP diagnosis and for the subsequent 1-year period were compared between CAP and comparison patients.

FINDINGS

38,010 (4·6%) HF patients and 48,703 (5·9%) COPD patients experienced a new CAP episode requiring hospitalization or outpatient care only, and were matched to comparison patients. In the HF subset, CAP patients were 47·2% more likely to experience an exacerbation vs patients without CAP (17·8% vs. 12·1%; p<0·001); in the COPD subset, CAP patients were 42·3% more likely to experience an exacerbation (16·2% vs. 11·4%; p<0·001).

CONCLUSIONS

Our data provide evidence that CAP foreshadows a prolonged increase in risk of exacerbation of underlying HF or COPD in adults, and suggests a potential benefit to CAP prevention strategies.

Rates and costs of invasive pneumococcal disease and pneumonia in persons with underlying medical conditions

Background

The presence of certain underlying medical conditions is known to increase the risk of pneumococcal disease in persons of all ages and across a wide spectrum of conditions, as demonstrated in two recent evaluations. Corresponding estimates of attributable economic costs have not been well characterized. We thus undertook a retrospective evaluation to estimate rates and costs of pneumococcal disease among children and adults with and without underlying medical conditions in the United States.

Methods

Data were obtained from three independent healthcare claims repositories. The study population included all persons enrolled in participating health plans during 2007–2010, and was stratified into subgroups based on age and risk profile: healthy; at-risk, due to selected comorbid conditions; and high-risk, due to selected immunocompromising conditions. At-risk and high-risk conditions, as well as episodes of invasive pneumococcal disease (IPD) and all-cause pneumonia (PNE), were identified via diagnosis, procedure, and drug codes. Rates and healthcare costs of IPD and PNE (2010US$) among at-risk and high-risk persons were compared with those from age-stratified healthy counterparts using incidence rate ratios (IRR) and cost ratios.

Results

Rates of IPD and PNE were consistently higher among at-risk persons (IRR = 4.1 [95 % CI 3.9–4.3] and 4.5 [4.49–4.53]) and high-risk persons (IRR = 10.3 [9.7–11.0] and 8.2 [8.2–8.3]) of all ages versus their healthy counterparts. Rates were notably high for at-risk persons with ≥2 conditions (IRR = 9.0 [8.4–9.7] and 10.3 [10.3–10.4]), as well as those with asthma (IRR = 3.4 [3.0–3.8] and 4.5 [4.47–4.53]) or diabetes (IRR = 4.3 [4.0–4.6] and 4.7 [4.6–4.7]). Healthcare costs totaled $21.7 million per 100,000 at-risk person-years and $58.5 million per 100,000 high-risk person-years, which were 8.7 [8.5–8.8] and 23.4 [22.9–23.8] times higher than corresponding costs for healthy persons.

Conclusions

Rates and costs of IPD and PNE are substantially higher among persons with certain chronic and immunocompromising conditions versus those without any such conditions. Rates and costs for persons with asthma and diabetes were especially increased, and rates and costs for individuals with ≥2 at-risk conditions approached those among persons with high-risk conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1432-4) contains supplementary material, which is available to authorized users.

Rates of pneumonia among children and adults with chronic medical conditions in Germany

Background

The objective of this study is to evaluate rates of all-cause pneumonia among “at-risk” and “high-risk” children and adults in Germany—in comparison with age-stratified healthy counterparts—during the period following the 2006 recommendation for universal immunization of infants with pneumococcal conjugate vaccine.

Methods

Retrospective cohort design and healthcare claims information for 3.4 M persons in Germany (2009–2012) were employed. Study population was stratified by age and risk profile (healthy, “at-risk” [with chronic medical conditions], and “high-risk” [immunocompromised]). At-risk and high-risk conditions, as well as episodes of all-cause pneumonia, were identified via diagnosis, procedure, and drug codes.

Results and discussion

Rates of all-cause pneumonia were 1.7 (95 % CI 1.7-1.8) to 2.5 (2.4-2.5) times higher among children and adults with at-risk conditions versus healthy counterparts, and 1.8 (1.8-1.9) to 4.1 (4.0-4.2) times higher among children and adults with high-risk conditions. Rates of all-cause pneumonia among at-risk persons increased in a graded and monotonic fashion with increasing numbers of conditions (i.e., risk stacking).

Conclusions

An increased risk for all-cause pneumonia in German children and adults with a spectrum of medical conditions persists in the era of widespread pneumococcal vaccination, and pneumonia risk in persons with ≥2 at-risk conditions is comparable or higher than those with high-risk conditions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1162-y) contains supplementary material, which is available to authorized users.

Population-based study of the association between asthma and pneumococcal disease in children

Background

Although asthma has recently been established as a risk factor for pneumococcal disease (PD), few studies have specifically evaluated this association in children.

Methods

We conducted a nation-wide population-based cohort study of the effect of asthma on childhood PD among all singleton live births in Denmark from 1994 to 2007, before the introduction of the 7-valent pneumococcal conjugate vaccine. All data were abstracted from Danish medical registries. Because underlying comorbidity substantially increases the PD risk in children, standard methods were used to assess the evidence of biologic interaction between comorbidity and asthma on the risk of PD.

Results

There were 2,253 cases of childhood PD among 888,655 children born in Denmark from 1994 to 2007. The adjusted incidence rate ratio of the effect of asthma on childhood PD was 2.2 (95% confidence interval [CI]: 2.0, 2.5). Age-stratified incidence rate ratios were 2.1 (95% CI: 1.8, 2.9) in children 6 months to <24 months, 4.1 (95% CI: 3.3, 5.1) in children 24 months to <60 months, and 2.3 (95% CI: 1.6, 3.2) in children ≥60 months. Evaluation of the biologic interaction between asthma and comorbidity in older children revealed that 55% (24 months to <60 months) to 73% (≥60 months) of cases among asthma-exposed children can be accounted for by the interaction between asthma and comorbidity.

Conclusion

These results confirm that asthma is an important risk factor for PD in children and suggest that children with underlying comorbidities are more sensitive to the effect of asthma on PD than children without comorbidities.

Rethinking risk for pneumococcal disease in adults: the role of risk stacking

Using data from 3 private healthcare claims repositories, we evaluated the incidence of pneumococcal disease among adults with US Advisory Committee on Immunization Practices (ACIP) defined at-risk conditions or rheumatoid arthritis, lupus, Crohn's disease, and neuromuscular disorder/seizures and those with traditional high-risk conditions. We observed that adults with ≥2 concurrent comorbid conditions had pneumococcal disease incidence rates that were as high as or higher than rates observed in those with traditional high-risk conditions.

Vaccination, underlying comorbidities, and risk of invasive pneumococcal disease

OBJECTIVES

Children with underlying conditions remain at increased risk for invasive pneumococcal diseases (IPD). This study describes the epidemiology, serotype distribution, clinical presentations, and outcomes of IPD in children with and without comorbidity.

METHODS

Cases of childhood IPD in Massachusetts were identified via enhanced surveillance from 2002 through 2014. Demographic and clinical data were collected via follow-up telephone interviews with parents and/or primary care providers. Underlying conditions were classified according to the 2012 Report of the Committee on Infectious Diseases and 2013 recommendations by the Advisory Committee on Immunization Practices.

RESULTS

Among 1052 IPD cases in Massachusetts children <18 years old, 22.1% had at least 1 comorbidity. Immunocompromising conditions (32.7%) and chronic respiratory diseases (22.4%) were most common. Children with comorbidities were older at the time of IPD diagnosis (median 54 vs 23 months, P < .001), had higher hospitalization (odds ratio 2.5; 95% confidence interval 1.7-3.6) and case-fatality rates (odds ratio 3.7; 95% confidence interval 1.5-8.9) compared with children without known underlying conditions after adjusting for age, gender, year of diagnosis, and pneumococcal vaccination status. During the last 2 years of the study, IPD among children with comorbidities was caused by non-pneumococcal conjugate vaccine 13 serotypes in 23-valent polysaccharide pneumococcal vaccine (6/12, 50%) or serotypes that are not included in any of the vaccines (6/12; 50%).

CONCLUSIONS

In children with comorbidity, IPD results in higher mortality, and a large proportion of disease is due to serotypes not included in current conjugate vaccines. Further research is needed, specifically to develop and evaluate additional strategies for prevention of IPD in the most vulnerable children.

Risk of pneumococcal disease in children with chronic medical conditions in the era of pneumococcal conjugate vaccine

BACKGROUND

In the current era of universal immunization of young children with pneumococcal conjugate vaccine, it is unclear whether the high risk ratios for pneumococcal disease previously attributed to specified chronic conditions have persisted. In addition, further analysis of pneumococcal disease risk may clarify whether certain chronic conditions that currently are not specified as significantly increasing the risk of pneumococcal disease should be so considered.

METHODS

We conducted a retrospective cohort analysis utilizing healthcare claims data from the period 2007-2010 to compare rates of pneumococcal disease among children <5 and 5-17 years of age with high-risk and at-risk conditions to rates among children without these conditions in the same age group. Risk profiles and manifestations of pneumococcal infection were ascertained from diagnosis, procedure, and drug codes.

RESULTS

Among at-risk children, rate ratios for invasive pneumococcal disease (vs children without at-risk/high-risk conditions) were 1.8 (95% confidence interval [CI], 1.4-2.3) in children <5 years of age and 3.3 (95% CI, 2.4-4.4) in children 5-17 years of age. Corresponding rate ratios for high-risk children were 11.2 (95% CI, 7.0-17.9) and 40.1 (95% CI, 28.8-56.0). Rate ratios increased in asthmatic children with increasing disease severity and in all at-risk children by the number of concurrent at-risk conditions. Rate ratios for pneumococcal pneumonia and all-cause pneumonia demonstrated similar patterns.

CONCLUSIONS

Children with high-risk and at-risk conditions continue to demonstrate an increased burden of pneumococcal disease. Pneumococcal disease rates are high among asthmatic children with moderate and severe disease and children with multiple at-risk conditions.

Rates of pneumococcal disease in adults with chronic medical conditions

BACKGROUND

Although it is widely accepted that adults with immunocompromising conditions are at greatly increased risk of pneumococcal infection, the extent of risk among immunocompetent adults with chronic medical conditions is less certain, particularly in the current era of universal vaccination of children with pneumococcal conjugate vaccines.

METHODS

We conducted a retrospective cohort study using data from 3 healthcare claims repositories (2006-2010) to compare rates of pneumococcal disease in immunocompetent adults with chronic medical conditions ("at-risk") and immunocompromised adults ("high-risk"), with rates in adults without these conditions ("healthy"). Risk profiles and episodes of pneumococcal disease-all-cause pneumonia, pneumococcal pneumonia, and invasive pneumococcal disease (IPD)-were ascertained from diagnosis, procedure, and drug codes.

RESULTS

Rates of all-cause pneumonia among at-risk persons aged 18-49 years, 50-64 years, and ≥65 years were 3.2 (95% confidence interval [CI], 3.1-3.2), 3.1 (95% CI, 3.1-3.1), and 3.0 (95% CI, 3.0-3.0) times the rates in age-matched healthy counterparts, respectively. We identified rheumatoid arthritis, systemic lupus erythematosus, Crohn's disease, and neuromuscular or seizure disorders as additional at-risk conditions for pneumococcal disease. Among persons with at-risk conditions, the rate of all-cause pneumonia substantially increased with the accumulation of concurrent at-risk conditions (risk stacking): among persons 18-49 years, rate ratios increased from 2.5 (95% CI, 2.5-2.5) in those with 1 at-risk condition to 6.2 (95% CI, 6.1-6.3) in those with 2 conditions, and to 15.6 (95% CI, 15.3-16.0) in those with ≥3 conditions. Findings for pneumococcal pneumonia and IPD were similar.

CONCLUSIONS

Despite widespread use of pneumococcal conjugate vaccines, rates of pneumonia and IPD remain disproportionately high in adults with at-risk conditions, including those with conditions not currently included in the Advisory Committee on Immunization Practices' guidelines for prevention and those with multiple at-risk conditions.

Estimated rate of reactivation of latent tuberculosis infection in the United States, overall and by population subgroup

We estimated the rate of reactivation tuberculosis (TB) in the United States, overall and by population subgroup, using data on TB cases and Mycobacterium tuberculosis isolate genotyping reported to the Centers for Disease Control and Prevention during 2006-2008. The rate of reactivation TB was defined as the number of non-genotypically clustered TB cases divided by the number of person-years at risk for reactivation due to prevalent latent TB infection (LTBI). LTBI was ascertained from tuberculin skin tests given during the 1999-2000 National Health and Nutrition Examination Survey. Clustering of TB cases was determined using TB genotyping data collected by the Centers for Disease Control and Prevention and analyzed via spatial scan statistic. Of the 39,920 TB cases reported during 2006-2008, 79.7% were attributed to reactivation. The overall rate of reactivation TB among persons with LTBI was estimated as 0.084 (95% confidence interval (CI): 0.083, 0.085) cases per 100 person-years. Rates among persons with and without human immunodeficiency virus coinfection were 1.82 (95% CI: 1.74, 1.89) and 0.073 (95% CI: 0.070, 0.075) cases per 100 person-years, respectively. The rate of reactivation TB among persons with LTBI was higher among foreign-born persons (0.098 cases/100 person-years; 95% CI: 0.096, 0.10) than among persons born in the United States (0.082 cases/100 person-years; 95% CI: 0.080, 0.083). Differences in rates of TB reactivation across subgroups support current recommendations for targeted testing and treatment of LTBI.

Randomized clinical trials to identify optimal antibiotic treatment duration

Background

Antibiotic resistance is a major barrier to the continued success of antibiotic treatment. Such resistance is often generated by overly long durations of antibiotic treatment. A barrier to identifying the shortest effective treatment duration is the cost of the sequence of clinical trials needed to determine shortest optimal duration. We propose a new method to identify the optimal treatment duration of an antibiotic treatment regimen.

Methods

Subjects are randomized to varying treatment durations and the cure proportions of these durations are linked using a logistic regression model, making effective use of information across all treatment duration groups. In this paper, Monte Carlo simulation is used to evaluate performance of such a model.

Results

Using a hypothetical dataset, the logistic regression model is seen to provide increased precision in defining the point estimate and confidence interval (CI) of the cure proportion at each treatment duration. When applied to the determination of non-inferiority, the regression model allows identification of the shortest duration meeting the predefined non-inferiority margin.

Conclusions

This analytic strategy represents a practical way to develop shortened regimens for tuberculosis and other infectious diseases. Application of this strategy to clinical trials of antibiotic therapy could facilitate decreased antibiotic usage, reduce cost, minimize toxicity, and decrease the emergence of antibiotic resistance.

Association of infant pneumococcal vaccination with pneumococcal pneumonia among mothers: a nested case-control study using the GPRD

Since implementation of infant immunization with 7-valent pneumococcal conjugate vaccine (PCV7), increased rates of pneumococcal pneumonia have been reported among adults. Using a cohort of mother-infant pairs identified from the General Practice Research Database in the UK we found that from 2006 to 2010 the annual incidence rate of pneumococcal pneumonia among mothers increased from 61/100,000 to 81/100,000. We identified 43 cases of pneumococcal pneumonia in mothers and 430 control mother-infant pairs. The conditional odds ratio of pneumococcal pneumonia in mothers whose infants received a three-dose series of PCV7 compared to mothers whose infants received zero, one, or two doses was 4.0 (95% confidence interval [95%CI]: 1.0-15.8), and 11.0 (95%CI: 1.2-98.6) when compared with mothers whose infants received no vaccinations. The incidence of pneumococcal pneumonia may have increased in mothers following the introduction of PCV7, possibly because mothers whose infants received PCV7 are at increased risk for pneumococcal pneumonia. Though there is a chance of bias inherent to observational studies, the study findings support close monitoring of adult pneumococcal disease and potential role of adult vaccination needs to be explored.

Serotype specific invasive capacity and persistent reduction in invasive pneumococcal disease

Defining the propensity of Streptococcus pneumoniae (SP) serotypes to invade sterile body sites following nasopharyngeal (NP) acquisition has the potential to inform about how much invasive pneumococcal disease (IPD) may occur in a typical population with a given distribution of carriage serotypes. Data from enhanced surveillance for IPD in Massachusetts children ≤7 years in 2003/04, 2006/07 and 2008/09 seasons and surveillance of SP NP carriage during the corresponding respiratory seasons in 16 Massachusetts communities in 2003/04 and 8 of the 16 communities in both 2006/07 and 2008/09 were used to compute a serotype specific "invasive capacity (IC)" by dividing the incidence of IPD due to serotype x by the carriage prevalence of that same serotype in children of the same age. A total of 206 IPD and 806 NP isolates of SP were collected during the study period. An approximate 50-fold variation in the point estimates between the serotypes having the highest (18C, 33F, 7F, 19A, 3 and 22F) and lowest (6C, 23A, 35F, 11A, 35B, 19F, 15A, and 15BC) IC was observed. Point estimates of IC for most of the common serotypes currently colonizing children in Massachusetts were low and likely explain the continued reduction in IPD from the pre-PCV era in the absence of specific protection against these serotypes. Invasive capacity differs among serotypes and as new pneumococcal conjugate vaccines are introduced, ongoing surveillance will be essential to monitor whether serotypes with high invasive capacity emerge (e.g. 33F, 22F) as successful colonizers resulting in increased IPD incidence due to replacement serotypes.

Implications for registry-based vaccine effectiveness studies from an evaluation of an immunization registry: a cross-sectional study

BACKGROUND

Population-based electronic immunization registries create the possibility of using registry data to conduct vaccine effectiveness studies which could have methodological advantages over traditional observational studies. For study validity, the base population would have to be clearly defined and the immunization status of members of the population accurately recorded in the registry. We evaluated a city-wide immunization registry, focusing on its potential as a tool to study pertussis vaccine effectiveness, especially in adolescents.

METHODS

We conducted two evaluations - one in sites that were active registry participants and one in sites that had implemented an electronic medical record with plans for future direct data transfer to the registry - of the ability to match patients' medical records to registry records and the accuracy of immunization records in the registry. For each site, records from current pediatric patients were chosen randomly. Data regarding pertussis-related immunizations, clinic usage, and demographic and identifying information were recorded; for 11-17-year-old subjects, information on MMR, hepatitis B, and varicella immunizations was also collected. Records were then matched, when possible, to registry records. For records with a registry match, immunization data were compared.

RESULTS

Among 350 subjects from sites that were current registry users, 307 (87.7%) matched a registry record. Discrepancies in pertussis-related data were common for up-to-date status (22.6%), number of immunizations (34.7%), dates (10.2%), and formulation (34.4%). Among 442 subjects from sites that planned direct electronic transfer of immunization data to the registry, 393 (88.9%) would have matched a registry record; discrepancies occurred frequently in number of immunizations (11.9%), formulation (29.1%), manufacturer (94.4%), and lot number (95.1%.) Inability to match and immunization discrepancies were both more common in subjects who were older at their first visit to the provider site. For 11-17-year-old subjects, discrepancies were also common for MMR, hepatitis B, and varicella vaccination data.

CONCLUSION

Provider records frequently could not be matched to registry records or had discrepancies in key immunization data. These issues were more common for older children and were present even with electronic data transfer. These results highlight general challenges that may face investigators wishing to use registry-based immunization data for vaccine effectiveness studies, especially in adolescents.

A ring expansion-annulation strategy for the synthesis of substituted azulenes. Preparation and Suzuki coupling reactions of 1-azulenyl triflates

[structure: see text]. A new strategy for the synthesis of substituted azulenes is reported, based on the reaction of beta'-bromo-alpha-diazo ketones with rhodium carboxylates. The key transformation involves intramolecular addition of a rhodium carbenoid to an arene pi-bond, electrocyclic ring opening, beta-elimination, tautomerization, and trapping to produce 1-hydroxyazulene derivatives. The synthetic utility of the method is enhanced by the ability of the triflate derivatives to participate in Suzuki coupling reactions, as illustrated in a synthesis of the antiulcer drug egualen sodium (KT1-32).

Technical report: irradiation of food. Committee on Environmental Health

Recent well-publicized outbreaks of foodborne illness have heightened general interest in food safety. Food irradiation is a technology that has been approved for use in selected foods in the United States since 1963. Widespread use of irradiation remains controversial, however, because of public concern regarding the safety of the technology and the wholesomeness of irradiated foods. In this report, we describe the technology, review safety and wholesomeness issues, and give a historical perspective of the public controversy regarding food irradiation.

Postterm delivery: a challenge for epidemiologic research

About 5% of babies are born postterm (that is, delivered after 42 completed weeks of gestation). Postterm infants experience more morbidity and mortality than term infants, prompting routine (and expensive) antenatal testing and active management of postterm pregnancies. This article reviews the epidemiology of postterm delivery. A few congenital conditions associated with disruption of the fetal-pituitary-adrenal axis as well as a rare maternal enzyme deficiency have long been identified with postterm delivery. In recent literature, environmental pollution, diet, and pharmaceutical agents have been associated with postterm birth. Very little systematic research has focused on identifying risk factors for this poorly understood birth outcome.

Birthweight of term infants and maternal occupation in a prospective cohort of pregnant women. The ALSPAC Study Team

OBJECTIVE

To study the relation between birthweight of term infants and maternal occupation.

METHODS

Information on job titles since the age of 16, and sociodemographic and other lifestyle factors were obtained by means of questionnaires as part of the Avon longitudinal study of pregnancy and childhood (ALSPAC), from a cohort of 14,000 pregnant women. The British 1990 standard occupational classification was used to code jobs within nine major job groups.

RESULTS

For 9282 women who delivered term infants and reported a job for the relevant period, there was a significant difference in mean birthweight among the nine major job groups. A 148 g difference was found between the mean birthweight of infants born to women with professional occupations and those with plant and machine operative jobs. Multiple regression analysis adjusted for sex of infant, parity, maternal height, smoking, caffeine consumption, and race. After adjustment the maternal job was no longer significantly associated with birthweight.

CONCLUSION

Despite the absence of a significant association between birthweight and job after adjustment, there were several findings which agreed with publications on maternal occupation and pregnancy outcome. The major job groups with the lowest birthweights included the following jobs; metal forming or welding, electric or electronic work, jobs in the textile trade, and assembling and working with equipment (mobile and stationary). The lack of an association may indicate that the study was of insufficient power to detect a small difference; it may indicate the presence of confounding variables that were not adjusted for or it may indicate that no association exists.

An investigation of the effect of paternal occupation group at conception on birth weight and gestational age. ALSPAC Study Team of Pregnancy and Childhood

The occupational histories of fathers were collected prospectively as part of the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC), and were used to investigate the association of paternal job title with a baby's birth weight and gestational age. The analysis cohort consisted of 4,795 singleton live-born babies whose fathers responded fully to questionnaire items regarding occupational history. Jobs were coded using the British Standard Occupational Codes and classified into nine major occupational groups. A 73-gram difference (95% CI: 0.16, 145.17) was found between the mean birth weight of full-term babies born of professional fathers (3,543 gm) and of fathers working in craft and related occupations (3,470 gm). This difference decreased and lost significance after controlling for sociodemographic variables. No difference was found in the mean birth weight of preterm babies, or in the rate of preterm delivery, when analyzed by paternal occupation at conception. Our results suggest that when important sociodemographic variables are known, the father's job title alone may not be a useful predictor of birth weight or preterm delivery.

Is there an association between preconception paternal x-ray exposure and birth outcome? The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood

Diagnostic x-rays are performed commonly on men of reproductive age, yet little is known about the potential effects of these x-rays on the future unborn children of such men. This study examines the possibility that preconception diagnostic x-ray studies of fathers may adversely effect their newborns. The authors used prospectively collected data from the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) for 7,678 birth records for women who gave birth in the County of Avon, England, in 1991-1992. Birth weight, gestational age, and fetal growth of infants whose fathers received diagnostic x-ray examinations likely to deliver significant gonadal doses within one year prior to conception were compared with infants whose fathers did not receive such x-rays. The mean birth weight of babies of exposed fathers was 3,358 g compared with a mean of 3,437 g in the unexposed group (p = 0.055). A similar difference was noted for intrauterine growth, 3,374 g exposed versus 3,437 g unexposed (p = 0.078). The downward trend in birth weight and fetal growth (birth weight adjusted for gestational age) persisted despite control for infants' sex and important parental variables such as age, height, race, education, occupational exposure, parity, and maternal smoking. Because medical x-rays are the largest controllable source of man-made ionizing radiation, more detailed study of the potential effect of paternal x-irradiation on progeny seems justified.

A protocol for selecting patients with injured extremities who need x-rays

To help curb excessive radiography, we developed a protocol for selecting patients with injured extremities who need x-ray examination, and we tested the protocol prospectively in 848 patients to determine its safety and effectiveness. Strict adherence to the protocol would have reduced x-ray usage by 12 per cent for upper extremities and 19 per cent for lower extremities. The actual reductions were 5 per cent and 16 per cent, respectively, since further reductions were limited by patient's demands for x-ray examinations. One fracture in 287 were missed, but the treatment was appropriate and the outcome satisfactory. By eliminating superfluous x-ray procedures, the protocol could reduce charges by $79 million to $139 million nationwide, without compromising quality of care or increasing malpractice liability. Nevertheless, even the best protocol cannot eliminate all negative x-ray studies. These results should serve as a stimulus for judicious use of radiography, but also as a warning to avoid overzealous cost-containment strategies that would reduce x-ray usage to below a safe threshold.