Risk of Death at 1 Year Following Postpartum Opioid Exposure

OBJECTIVE

 Opioids are commonly prescribed to women for acute pain following childbirth. Postpartum prescription opioid exposure is associated with adverse opioid-related morbidities but the association with all-cause mortality is not well studied. This study aimed to examine the association between postpartum opioid prescription fills and the 1-year risk of all-cause mortality among women with live births.

METHODS

 In a retrospective cohort study of live births among women enrolled in Tennessee Medicaid (TennCare) between 2007 and 2015, we compared women who filled two or more postpartum outpatient opioid prescriptions (up to 41 days of postdelivery discharge) to women who filled one or fewer opioid prescription. Women were followed from day 42 postdelivery discharge through 365 days of follow-up or date of death. Deaths were identified using linked death certificates (2007-2016). We used Cox's proportional hazard regression and inverse probability of treatment weights to compare time to death between exposure groups while adjusting for relevant confounders. We also examined effect modification by delivery route, race, opioid use disorder, use of benzodiazepines, and mental health condition diagnosis.

RESULTS

 Among 264,135 eligible births, 216,762 (82.1%) had one or fewer maternal postpartum opioid fills and 47,373 (17.9%) had two or more fills. There were 182 deaths during follow-up. The mortality rate was higher in women with two or more fills (120.5 per 100,000 person-years) than in those with one or fewer (57.7 per 100,000 person-years). The risk of maternal death remained higher in participants exposed to two or more opioid fills after accounting for relevant covariates using inverse probability of treatment weighting (adjusted hazard ratio: 1.46 [95% confidence interval: 1.01, 2.09]). Findings from stratified analyses were consistent with main findings.

CONCLUSION

 Filling two or more opioid prescriptions during the postpartum period was associated with a significant increase in 1-year risk of death among new mothers.

KEY POINTS

· Opioid prescribing in the postpartum period is common.. · Prior studies show that >1 postnatal opioid fill is associated with adverse opioid-related events.. · > 1 opioid fill within 42 days of delivery was associated with an increase in 1-year risk of death..

Association between nasopharyngeal colonization with multiple pneumococcal serotypes and total pneumococcal colonization density in young Peruvian children

OBJECTIVES

We examined the association of nasopharyngeal (NP) pneumococcal co-colonization (>1 pneumococcal serotype) and pneumococcal density in young Peruvian children enrolled in a prospective cohort study.

METHODS

NP swabs collected monthly from children aged <3 years during both asymptomatic and acute respiratory illness (ARI) periods underwent culture-enriched microarray for pneumococcal detection and serotyping and lytA polymerase chain reaction for density assessment. We examined the serotypes commonly associated with co-colonization and the distribution of densities by co-colonization, age, current ARI, and other covariates. The association of co-colonization and pneumococcal density was assessed using a multivariable mixed-effects linear regression model, accounting for repeated measures and relevant covariates.

RESULTS

A total of 27 children contributed 575 monthly NP samples. Pneumococcus was detected in 302 of 575 (53%) samples, and co-colonization was detected in 61 of these 302 (20%). The total densities were higher during ARI than non-ARI periods and lowest among the youngest children, increasing with age. In the multivariable analysis, there was no significant association between pneumococcal density and co-colonization (coefficient estimate 0.22, 95% confidence interval 0.11-0.55; reference: single-serotype detections). Serotypes 23B and 19F were detected significantly more frequently as single isolates.

CONCLUSION

Pneumococcal co-colonization was common and not associated with increased pneumococcal density. Differential propensity for co-colonization was observed among individual serotypes.

Monitoring Multiple U.S. Government-Supported Covid-19 Vaccine Trials

Monitoring U.S. Government-Supported Covid-19 Vaccine TrialsOperation Warp Speed was a partnership created to accelerate the development of Covid-19 vaccines. The National Institutes of Health oversaw one data and safety monitoring board to review/monitor all Operation Warp Speed trials. This article describes the challenges faced in monitoring these trials and provides ideas for future similar endeavors.

Comparative effectiveness of metformin versus sulfonylureas on kidney function decline or death among patients with reduced kidney function: a retrospective cohort study

BACKGROUND

Diabetes often causes kidney disease. In this study, we sought to evaluate if metformin use was associated with death or kidney events in patients with diabetes and concurrent reduced kidney function.

METHODS

We used data from the Veterans Health Administration, Medicare and National Death Index databases to assemble a national retrospective cohort of veterans who were using metformin or sulfonylureas from 2001 through 2016 and who began follow-up at an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m². The primary composite outcome was a kidney event (i.e., 40% decline in eGFR or end-stage renal disease) or death. The secondary outcome was a kidney event (eGFR decline or end-stage renal disease). We weighted the cohort using propensity scores and used Cox proportional models to estimate the cause-specific hazard of outcomes and of treatment nonpersistence as a competing risk. We stratified follow-up into 2 periods, namely the first 360 days from the start of follow-up, and 361 days and beyond.

RESULTS

In the first 360 days, the propensity score-weighted cohort included 24 883 patients who used metformin and 24 998 who used sulfonylureas. There were 33.5 (95% confidence interval [CI] 30.9-36.3) and 43.0 (95% CI 40.1-46.0) deaths or kidney events per 1000 person-years for patients who used metformin or sulfonylureas, respectively (hazard ratio [HR] 0.78, 95% CI 0.71-0.85). For the secondary outcome of kidney events, the HR was 0.94 (95% CI 0.67-1.33). In the second period from 361 days onward, the primary outcome event rate was 26.5 (95% CI 24.7-28.5) per 1000 person-years for those who used metformin, compared with 36.3 (95% CI 34.2-38.6) per 1000 person-years for those who used sulfonylureas (HR 0.73, 95% CI 0.67-0.79). Results were consistent for kidney events alone (HR 0.73, 95% CI 0.59-0.91).

INTERPRETATION

Metformin use for 361 days or longer after reaching an eGFR of less than 60 mL/min/1.73 m² was associated with decreased likelihood of kidney events or death in patients with diabetes, compared with use of sulfonylureas. Metformin provided end-organ protection, in addition to glucose control.

Impact of prior underinsurance on cervical cancer screening among Davidson County, Tennessee, women diagnosed with invasive cervical cancer, 2008-2018

INTRODUCTION

We sought to investigate the association between insurance coverage history and cervical cancer screening among Davidson County, Tennessee, women diagnosed with incident cervical cancer.

METHODS

We reviewed medical records of women diagnosed with invasive cervical cancer from 2008 through 2018 identified via the state's cancer registry and by active surveillance of diagnostic pathology reports for the HPV-IMPACT project. Per 2012 United States Preventive Services Task Force recommended cervical cancer screening guidelines, women were characterized into three screening history categories: "no screening", "no follow-up" and "test/screening failure". Multivariable logistic regression measured the association of prior inadequate insurance (underinsurance) and screening history ("no screening/no follow-up" compared to "test/screening failure").

RESULTS

Of 212 women, most (77%) had not undergone recommended cervical cancer screening or follow-up prior to cancer diagnosis. Overall, 28% of women had history of underinsurance in 5 years prior to diagnosis. In adjusted analyses, underinsured women were more likely to have a "no screening/no follow-up" prior to cancer diagnosis (aOR 4.26; 95% CI 1.15-15.80) compared to "test/screening failure" history. Non-white race (aOR 2.73; 95% CI 0.98-7.61), older age (aOR 1.03 per year; 95% CI 1.00-1.07), and history of smoking (aOR 4.07; 95% CI 1.54-10.74) were also associated with increased likelihood of "no screening/no follow-up".

CONCLUSIONS

Previous underinsurance was independently associated with non-adherence to cervical cancer screening and follow-up guidelines among women with incident cervical cancer. Further study of factors contributing to inadequate cervical cancer screening and interventions to increase cervical cancer screening in high-risk populations is needed.

Human Papillomavirus Vaccine Impact on Cervical Precancers in a Low-Vaccination Population

INTRODUCTION

Demonstrating human papillomavirus vaccine impact is critical for informing guidelines to increase vaccination and decrease human papillomavirus‒related outcomes, particularly in states with suboptimal vaccination coverage, such as Tennessee. This study examines the trends in high-grade cervical lesion incidence among Tennessee Medicaid-enrolled women aged 18-39 years and the subset of women who were screened for cervical cancer.

METHODS

Using a validated claims-based model to identify incident cervical intraepithelial neoplasia Grades 2 or 3 or adenocarcinoma in situ events, annual age group‒specific incidence rates from Tennessee Medicaid billing data, 2008-2018, were calculated. Significant trends were determined by Joinpoint. Analyses were conducted in 2020.

RESULTS

From 2008 to 2018, high-grade cervical lesion incidence significantly declined in women aged 18-20 years (average annual percentage change= -31.9, 95% CI= -38.6, -24.6), 21-24 years (average annual percentage change= -12.9, 95% CI= -22.3, -2.4), and 25-29 years (average annual percentage change= -6.4, 95% CI= -8.1, -4.6). Among screened women, rates significantly declined for ages 18-20 years (average annual percentage change= -20.3, 95% CI= -25.3, -15.0), 21-24 years (average annual percentage change= -10.2, 95% CI= -12.6, -7.8), and 25-29 years (average annual percentage change= -2.6, 95% CI= -3.9, -1.2). Trends from 2008 to 2018 were stable for older age groups (30-34 and 35-39 years).

CONCLUSIONS

Results show reductions in high-grade cervical lesion incidence among ages most likely to have benefited from the human papillomavirus vaccine. Declines among young, screened women suggest causes other than reduction in screening. Evidence of vaccine impact in populations with low-vaccination coverage, such as Tennessee, is promising.

Prevalence of prescription opioid use during pregnancy in eight US health plans during 2001-2014

PURPOSE

To estimate prevalence of prescription opioid use during pregnancy in eight US health plans during 2001-2014.

METHODS

We conducted a cohort study of singleton live birth deliveries. Maternal characteristics were ascertained from health plan and/or birth certificate data and opioids dispensed during pregnancy from health plan pharmacy records. Prevalence of prescription opioid use during pregnancy was calculated for any use, cumulative days of use, and number of dispensings.

RESULTS

We examined prevalence of prescription opioid use during pregnancy in each health plan. Tennessee Medicaid had appreciably greater prevalence of use compared to the seven other health plans. Thus, results for the two groups were reported separately. In the seven health plans (n = 587 093 deliveries), prevalence of use during pregnancy was relatively stable at 9%-11% throughout 2001-2014. In Tennessee Medicaid (n = 256 724 deliveries), prevalence increased from 29% in 2001 to a peak of 36%-37% in 2004-2010, and then declined to 28% in 2014. Use for ≥30 days during pregnancy was stable at 1% in the seven health plans and increased from 2% to 7% in Tennessee Medicaid during 2001-2014. Receipt of ≥5 opioid dispensings during pregnancy increased in the seven health plans (0.3%-0.6%) and Tennessee Medicaid (3%-5%) during 2001-2014.

CONCLUSION

During 2001-2014, prescription opioid use during pregnancy was more common in Tennessee Medicaid (peak prevalence in late 2000s) compared to the seven health plans (relatively stable prevalence). Although a small percentage of women had opioid use during pregnancy for ≥30 days or ≥ 5 dispensings, they represent thousands of women during 2001-2014.

Assessing the impact of acute respiratory illnesses on the risk of subsequent respiratory illness

BACKGROUND

Whether acute respiratory illnesses (ARIs), often associated with virus detection, are associated with lower risk for subsequent ARI remains unclear. We assessed the association between symptomatic ARI and subsequent ARI in young children.

METHODS

In a prospective cohort of Peruvian children <3 years, we examined the impact of index ARI on subsequent ARI risk. Index ARI were matched with ≤3 asymptomatic observations and followed over 28 days. We compared risk of subsequent ARI between groups using conditional logistic regression adjusting for several covariates, accounting for repeat observations from individual children.

RESULTS

Among 983 index ARI, 339 (34%) had an ARI event during follow-up, compared with 876/2826 (31%) matched asymptomatic observations. We found no significant association of index ARI and subsequent ARI risk during follow-up overall (aOR 1.10, 95% CI 0.98, 1.23) or when limited to index ARI with respiratory viruses detected (aOR 1.03, 95% CI 0.86, 1.24). Similarly, when the outcome was limited to ARI in which viruses were detected, no significant association was seen (aOR 1.05, 95% CI 0.87, 1.27).

DISCUSSION

ARIs were not associated with short-term protection against subsequent ARI in these children. Additional longitudinal studies are needed to understand drivers of recurrent ARI in young children.

Data and Safety Monitoring of COVID-19 Vaccine Clinical Trials

To speed the development of vaccines against SARS-CoV-2, the United States Federal Government has funded multiple phase 3 trials of candidate vaccines. A single 11-member data and safety monitoring board (DSMB) monitors all government-funded trials to ensure coordinated oversight, promote harmonized designs, and allow shared insights related to safety across trials. DSMB reviews encompass 3 domains: (1) the conduct of trials, including overall and subgroup accrual and data quality and completeness; (2) safety, including individual events of concern and comparisons by randomized group; and (3) interim analyses of efficacy when event-driven milestones are met. Challenges have included the scale and pace of the trials, the frequency of safety events related to the combined enrollment of over 100 000 participants, many of whom are older adults or have comorbid conditions that place them at independent risk of serious health events, and the politicized environment in which the trials have taken place.

Prescription Opioid Dose After Vaginal Delivery and the Risk of Serious Opioid-Related Events: A Retrospective Cohort Study

PURPOSE

Postpartum opioid use remains common among women with uncomplicated vaginal delivery and may increase the risk of serious opioid-related events. Therefore, we examined the association between the dose of the first filled opioid prescription after vaginal delivery and the subsequent risk of serious opioid-related events.

METHODS

We conducted a retrospective cohort study among women enrolled in Tennessee Medicaid with a vaginal delivery (2007-2015). We used Cox proportional hazards regression to model adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for serious opioid-related events after delivery according to the dose (morphine milligram equivalents [MME]) of the first postpartum opioid prescription, accounting for comorbidities, medication use, parity, and delivery complications. Serious opioid-related events were defined as the occurrence of persistent opioid use, a methadone or buprenorphine fill, opioid use disorder diagnosis, opioid overdose, or opioid-related death. We used filled pharmacy data to characterize the dose of the first postpartum opioid prescription filled within 4 days after delivery.

RESULTS

More than one-half of women (53.2%; n = 147,598) filled an opioid prescription within 4 days of a vaginal delivery. After accounting for baseline risk factors, filling a postpartum opioid prescription was associated with an increased risk of serious opioid-related events across all dose categories, compared with women filling none (aHR 1-99 MME, 1.52; 95% CI, 1.33-1.74; aHR 100-149 MME, 1.41; 95% CI, 1.26-1.58; aHR 150-199 MME, 1.40; 95% CI, 1.26-1.57: and aHR ≥200 MME, 1.60; 95% CI, 1.43-1.78).

CONCLUSIONS

Filling a postpartum opioid prescription after a vaginal delivery was associated with an increased risk of serious opioid-related events, regardless of dose. Prescribing guidelines should discourage the routine prescribing of opioids after vaginal delivery.

Hospitalization for Heart Failure Among Patients With Diabetes Mellitus and Reduced Kidney Function Treated With Metformin Versus Sulfonylureas: A Retrospective Cohort Study

Background Metformin and sulfonylurea are commonly prescribed oral medications for type 2 diabetes mellitus. The association of metformin and sulfonylureas on heart failure outcomes in patients with reduced estimated glomerular filtration rate remains poorly understood. Methods and Results This retrospective cohort combined data from National Veterans Health Administration, Medicare, Medicaid, and the National Death Index. New users of metformin or sulfonylurea who reached an estimated glomerular filtration rate of 60 mL/min per 1.73 m2 or serum creatinine of 1.5 mg/dL and continued metformin or sulfonylurea were included. The primary outcome was hospitalization for heart failure. Echocardiogram reports were obtained to determine each patient's ejection fraction (EF) (reduced EF <40%; midrange EF 40%-49%; ≥50%). The primary analysis estimated the cause-specific hazard ratios for metformin versus sulfonylurea and estimated the cumulative incidence functions for heart failure hospitalization and competing events. The weighted cohort included 24 685 metformin users and 24 805 sulfonylurea users with reduced kidney function (median age 70 years, estimated glomerular filtration rate 55.8 mL/min per 1.73 m2). The prevalence of underlying heart failure (12.1%) and cardiovascular disease (31.7%) was similar between groups. There were 16.9 (95% CI, 15.8-18.1) versus 20.7 (95% CI, 19.5-22.0) heart failure hospitalizations per 1000 person-years for metformin and sulfonylurea users, respectively, yielding a cause-specific hazard of 0.85 (95% CI, 0.78-0.93). Among heart failure hospitalizations, 44.5% did not have echocardiogram information available; 29.3% were categorized as reduced EF, 8.9% as midrange EF, and 17.2% as preserved EF. Heart failure hospitalization with reduced EF (hazard ratio, 0.79; 95% CI, 0.67-0.93) and unknown EF (hazard ratio, 0.84; 95% CI 0.74-96) were significantly lower in metformin versus sulfonylurea users. Conclusions Among patients with type 2 diabetes mellitus who developed worsening kidney function, persistent metformin compared with sulfonylurea use was associated with reduced heart failure hospitalization.

Improving Cervical Precancer Surveillance: Validity of Claims-Based Prediction Models in ICD-9 and ICD-10 Eras

Background

Human papillomavirus vaccine (HPV) impact on cervical precancer (cervical intraepithelial neoplasia grades 2+ [CIN2+]) is observable sooner than impact on cancer. Biopsy-confirmed CIN2+ is not included in most US cancer registries. Billing codes could provide surrogate metrics; however, the International Classification of Diseases, ninth (ICD-9) to tenth (ICD-10) transition disrupts trends. We built, validated, and compared claims-based models to identify CIN2+ events in both ICD eras.

Methods

A database of Davidson County (Nashville), Tennessee, pathology-confirmed CIN2+ from the HPV Vaccine Impact Monitoring Project (HPV-IMPACT) provided gold standard events. Using Tennessee Medicaid 2008-2017, cervical diagnostic procedures (N = 8549) among Davidson County women aged 18-39 years were randomly split into 60% training and 40% testing sets. Relevant diagnosis, procedure, and screening codes were used to build models from CIN2+ tissue diagnosis codes alone, least absolute shrinkage and selection operator (LASSO), and random forest. Model-classified index events were counted to estimate incident events.

Results

HPV-IMPACT identified 983 incident CIN2+ events. Models identified 1007 (LASSO), 1245 (CIN2+ tissue diagnosis codes alone), and 957 (random forest) incident events. LASSO performed well in ICD-9 and ICD-10 eras: 77.3% (95% confidence interval [CI] = 72.5% to 81.5%) vs 81.1% (95% CI = 71.5% to 88.6%) sensitivity, 93.0% (95% CI = 91.9% to 94.0%) vs 90.2% (95% CI = 87.2% to 92.7%) specificity, 61.3% (95% CI = 56.6% to 65.8%) vs 60.3% (95% CI = 51.0% to 69.1%) positive predictive value, 96.6% (95% CI = 95.8% to 97.3%) vs 96.3% (95% CI = 94.1% to 97.8%) negative predictive value, 91.0% (95% CI = 89.9% to 92.1%) vs 88.8% (95% CI = 85.9% to 91.2%) accuracy, and 85.1% (95% CI = 82.9% to 87.4%) vs 85.6% (95% CI = 81.4% to 89.9%) C-indices, respectively; performance did not statistically significantly differ between eras (95% confidence intervals all overlapped).

Conclusions

Results confirmed model utility with good performance across both ICD eras for CIN2+ surveillance. Validated claims-based models may be used in future CIN2+ trend analyses to estimate HPV vaccine impact where population-based biopsies are unavailable.

Building a Data Linkage Foundation for Mother-Child Pharmacoepidemiology Research

BACKGROUND

Expanding our understanding of the effects of maternal medication exposure through research is a public health priority and will help inform both clinical and policy decision making, ultimately improving outcomes for pregnant women and their children.

OBJECTIVE

Our objective was to describe a linked-data research platform that facilitates studies of pregnancy medication exposures and policy changes on maternal and child health outcomes.

METHODS

Mothers receiving Medicaid benefits were probabilistically linked with newborns in the Tennessee Medicaid program (TennCare) through three distinct linkage processes. Medicaid claims data and state birth and fetal death certificate records (vital records) were used to identify and link potential mothers, deliveries, and newborn children. The linkage process started with the creation of a merged pool of potential mothers and eligible deliveries, which was linked to vital records and to children's records. In the last step, linked records from the preceding steps were combined into the final Mother-child linked records. For each data linkage step, rubrics and scoring systems for exact and partial matches and mismatches among key linkage fields were applied and used to examine the strength of the probabilistic linkages. Summary linkage yields for year 2013 are reported for illustration purposes.

RESULTS

Among the 84,253 potential deliveries, 1,761,557 eligible potential mothers, and 51,400 eligible children identified in Tennessee Medicaid records in 2013, a total of 60,265 of these records were uniquely linked to vital records, including 46,172 (77%) with linked mother-child-vital records. Among the 51,400 eligible children records identified in Tennessee Medicaid for that year, 97% (50,053) had at least one link to vital records or a mother-delivery record. In linked records, the median maternal age was 24 years, and the median gestational age was 39 weeks. About 33% of pregnant women underwent cesarean birth, and 1% of births were classified as complicated deliveries.

CONCLUSIONS

Supplementing existing Medicaid claims data with birth certificate records complements administrative claims information and allows for detailed assessments of pregnancy exposures and policy changes on mother and child outcomes.

Developing a Standardized and Reusable Method to Link Distributed Health Plan Databases to the National Death Index: Methods Development Study Protocol

BACKGROUND

Certain medications may increase the risk of death or death from specific causes (eg, sudden cardiac death), but these risks may not be identified in premarket randomized trials. Having the capacity to examine death in postmarket safety surveillance activities is important to the US Food and Drug Administration's (FDA) mission to protect public health. Distributed networks of electronic health plan databases used by the FDA to conduct multicenter research or medical product safety surveillance studies often do not systematically include death or cause-of-death information.

OBJECTIVE

This study aims to develop reusable, generalizable methods for linking multiple health plan databases with the Centers for Disease Control and Prevention's National Death Index Plus (NDI+) data.

METHODS

We will develop efficient administrative workflows to facilitate multicenter institutional review board (IRB) review and approval within a distributed network of 6 health plans. The study will create a distributed NDI+ linkage process that avoids sharing of identifiable patient information between health plans or with a central coordinating center. We will develop standardized criteria for selecting and retaining NDI+ matches and methods for harmonizing linked information across multiple health plans. We will test our processes within a use case comprising users and nonusers of antiarrhythmic medications.

RESULTS

We will use the linked health plan and NDI+ data sets to estimate the incidences and incidence rates of mortality and specific causes of death within the study use case and compare the results with reported estimates. These comparisons provide an opportunity to assess the performance of the developed NDI+ linkage approach and lessons for future studies requiring NDI+ linkage in distributed database settings. This study is approved by the IRB at Harvard Pilgrim Health Care in Boston, MA. Results will be presented to the FDA at academic conferences and published in peer-reviewed journals.

CONCLUSIONS

This study will develop and test a reusable distributed NDI+ linkage approach with the goal of providing tested NDI+ linkage methods for use in future studies within distributed data networks. Having standardized and reusable methods for systematically obtaining death and cause-of-death information from NDI+ would enhance the FDA's ability to assess mortality-related safety questions in the postmarket, real-world setting.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/21811.

Changes in Otitis Media Episodes and Pressure Equalization Tube Insertions Among Young Children Following Introduction of the 13-Valent Pneumococcal Conjugate Vaccine: A Birth Cohort-based Study

BACKGROUND

The impact of 13-valent pneumococcal conjugate vaccine (PCV13) introduction on the occurrence of first and subsequent otitis media (OM) episodes in early childhood is unclear. We compared the risk of OM episodes among children age <2 years before and after PCV13 introduction, accounting for the dependence between OM episodes.

METHODS

We identified consecutive annual (July-June) cohorts of Tennessee Medicaid-enrolled children (2006-2014) from birth through age 2 years. We identified OM episodes using coded diagnoses (we classified diagnoses <21 days apart as the same episode). We modeled adjusted hazard ratios (aHRs) for OM comparing 7-valent pneumococcal conjugate vaccine (PCV7)-era (2006-2010) and PCV13-era (2011-2014) birth cohorts, accounting for risk factors and dependence between first and subsequent episodes. Secondary analyses examined pressure equalization tube (PET) insertions and compared the risk of recurrent OM (≥3 episodes in 6 months or ≥4 episodes in 12 months) between PCV7- and PCV13-era birth cohorts.

RESULTS

We observed 618 968 OM episodes and 24 875 PET insertions among 368 063 children. OM and PET insertion rates increased during the PCV7 years and declined after PCV13 introduction. OM and PET insertion risks were lower in the 2013-2014 cohort compared with the 2009-2010 cohort (aHRs [95% confidence interval], 0.92 [.91-.93] and 0.76 [.72-.80], respectively). PCV13 introduction was associated with declines in the risk of first, subsequent, and recurrent OM.

CONCLUSIONS

The transition from PCV7 to PCV13 was associated with a decline of OM among children aged <2 years due to a reduction in the risk of both the first and subsequent OM episodes.

Validity of diagnosis and procedure codes for identifying neural tube defects in infants

PURPOSE

The use of validated criteria to identify birth defects in electronic healthcare databases can avoid the cost and time-intensive efforts required to conduct chart reviews to confirm outcomes. This study evaluated the validity of various case-finding methodologies to identify neural tube defects (NTDs) in infants using an electronic healthcare database.

METHODS

This analysis used data generated from a study whose primary aim was to evaluate the association between first-trimester maternal prescription opioid use and NTDs. The study was conducted within the Medication Exposure in Pregnancy Risk Evaluation Program. A broad approach was used to identify potential NTDs including diagnosis and procedure codes from inpatient and outpatient settings, death certificates and birth defect flags in birth certificates. Potential NTD cases were chart abstracted and confirmed by clinical experts. Positive predictive values (PPVs) and 95% confidence intervals (95% CI) are reported.

RESULTS

The cohort included 113 168 singleton live-born infants: 55 960 infants with opioid exposure in pregnancy and 57 208 infants unexposed in pregnancy. Seventy-three potential NTD cases were available for the validation analysis. The overall PPV was 41% using all diagnosis and procedure codes plus birth certificates. Restricting approaches to codes recorded in the infants' medical record or to birth certificate flags increased the PPVs (72% and 80%, respectively) but missed a substantial proportion of confirmed NTDs.

CONCLUSIONS

Codes in electronic healthcare data did not accurately identify confirmed NTDs. These results indicate that chart review with adjudication of outcomes is important when conducting observational studies of NTDs using electronic healthcare data.

Pneumonia Hospitalization Coding Changes Associated With Transition From the 9th to 10th Revision of International Classification of Diseases

Objectives:

To evaluate the impact of International Classification of Disease, 10th revision, Clinical Modification (ICD-10-CM) implementation on pneumonia hospitalizations rates, which had declined following pneumococcal conjugate vaccine introduction for infants in 2000.

Methods:

We randomly selected records from a single hospital 1 year before (n = 500) and after (n = 500) October 2015 implementation of ICD-10-CM coding. We used a validated ICD-9-CM algorithm and translation of that algorithm to ICD-10-CM to identify pneumonia hospitalizations pre- and post-implementation, respectively. We recoded ICD-10-CM records to ICD-9-CM and vice versa. We calculated sensitivity and positive predictive value (PPV) of the ICD-10-CM algorithm using ICD-9-CM coding as the reference. We used sensitivity and PPV values to calculate an adjustment factor to apply to ICD-10 era rates to enable comparison with ICD-9-CM rates. We reviewed primary diagnoses of charts not meeting the pneumonia definition when recoded.

Results:

Sensitivity and PPV of the ICD-10-CM algorithm were 94% and 92%, respectively, for young children and 74% and 79% for older adults. The estimated adjustment factor for ICD-10-CM period rates was −2.09% (95% credible region [CR], −7.71% to +3.0%) for children and +6.76% (95% CR, −3.06% to +16.7%) for older adults. We identified a change in coding adult charts that met the ICD-9-CM pneumonia definition that led to recoding in ICD-10-CM as chronic obstructive pulmonary disease (COPD) exacerbation.

Conclusions:

The ICD-10-CM algorithm derived from a validated ICD-9-CM algorithm should not introduce substantial bias for evaluating pneumonia trends in children. However, changes in coding of pneumonia associated with COPD in adults warrant further study.

Hospitalization for Lactic Acidosis Among Patients With Reduced Kidney Function Treated With Metformin or Sulfonylureas

OBJECTIVE

To compare the risk of lactic acidosis hospitalization between patients treated with metformin versus sulfonylureas following development of reduced kidney function.

RESEARCH DESIGN AND METHODS

This retrospective cohort combined data from the National Veterans Health Administration, Medicare, Medicaid, and the National Death Index. New users of metformin or sulfonylureas were followed from development of reduced kidney function (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m² or serum creatinine ≥1.4 mg/dL [female] or 1.5 mg/dL [male]) through hospitalization for lactic acidosis, death, loss to follow-up, or study end. Lactic acidosis hospitalization was defined as a composite of primary discharge diagnosis or laboratory-confirmed lactic acidosis (lactic acid ≥2.5 mmol/L and either arterial blood pH <7.35 or serum bicarbonate ≤19 mmol/L within 24 h of admission). We report the cause-specific hazard of lactic acidosis hospitalization between metformin and sulfonylureas from a propensity score-matched weighted cohort and conduct an additional competing risks analysis to account for treatment change and death.

RESULTS

The weighted cohort included 24,542 metformin users and 24,662 sulfonylurea users who developed reduced kidney function (median age 70 years, median eGFR 55.8 mL/min/1.73 m²). There were 4.18 (95% CI 3.63, 4.81) vs. 3.69 (3.19, 4.27) lactic acidosis hospitalizations per 1,000 person-years among metformin and sulfonylurea users, respectively (adjusted hazard ratio [aHR] 1.21 [95% CI 0.99, 1.50]). Results were consistent for both primary discharge diagnosis (aHR 1.11 [0.87, 1.44]) and laboratory-confirmed lactic acidosis (1.25 [0.92, 1.70]).

CONCLUSIONS

Among veterans with diabetes who developed reduced kidney function, occurrence of lactic acidosis hospitalization was uncommon and not statistically different between patients who continued metformin and those patients who continued sulfonylureas.

Trends in High-grade Cervical Lesions and Cervical Cancer Screening in 5 States, 2008-2015

BACKGROUND

We describe changes in rates of cervical intraepithelial neoplasia grades 2, 3 and adenocarcinoma in situ (CIN2+) during a period of human papillomavirus (HPV) vaccine uptake and changing cervical cancer screening recommendations.

METHODS

We conducted population-based laboratory surveillance for CIN2+ in catchment areas in 5 states, 2008-2015. We calculated age-specific CIN2+ rates per 100000 women by age groups. We estimated incidence rate ratios (IRR) of CIN2+ for 2-year periods among all women and among screened women to evaluate changes over time.

RESULTS

A total of 16572 CIN2+ cases were reported. Among women aged 18-20 and 21-24 years, CIN2+ rates declined in all sites, whereas in women aged 25-29, 30-34, and 35-39 years, trends differed across sites. The percent of women screened annually declined in all sites and age groups. Compared to 2008-2009, rates among screened women were significantly lower for all 3 periods in women aged 18-20 years (2010-2011: IRR 0.82, 95% confidence interval [CI] 0.67-0.99; 2012-2013: IRR 0.63, 95% CI 0.47-0.85; 2014-2015: IRR 0.44, 95% CI 0.28-0.68) and lower for the latter 2 time periods in women aged 21-24 years (2012-2013: IRR 0.86, 95% CI 0.79-0.94; 2014-2015: IRR 0.61, 95% CI 0.55-0.67).

CONCLUSIONS

From 2008-2015, both CIN2+ rates and cervical cancer screening declined in women aged 18-24 years. The significant decreases in CIN2+ rates among screened women aged 18-24 years are consistent with a population-level impact of HPV vaccination.

Mental health conditions and the risk of chronic opioid therapy among patients with rheumatoid arthritis: a retrospective veterans affairs cohort study

OBJECTIVE

Patients with rheumatoid arthritis (RA) often receive opioid analgesics for pain management. We examined the association between mental health conditions and the risk of chronic opioid therapy.

METHODS

A retrospective cohort of veterans with RA initiating opioid use was assembled using Veterans Health Administration databases (2001-2012). Mental health conditions included anxiety (N = 1108, 12.9%), depression (N = 1912, 22.2%), bipolar disease (N = 131, 1.5%), and post-traumatic stress disorder (N = 768, 8.9%) and were identified by ICD coded diagnoses and use of specific medications. Cohort members were followed from opioid initiation through chronic opioid therapy, defined as the continuous availability of opioids for at least 90 days. Multivariable Cox proportional hazard regression models assessed the association between mental health conditions and chronic opioid therapy accounting for relevant covariates. Subgroup analyses examined whether the strength of the observed association varied by the duration of the initial opioid prescription.

RESULTS

We identified 14,767 patients with RA with 22,452 episodes of opioid use initiation. Mental health conditions were identified in 8607 (38.3%) patients. Compared with patients without mental health conditions, patients with mental health conditions have a higher risk of developing chronic opioid therapy (469.3 vs 378.1 per 1000 person-years, adjusted hazard ratio [aHR] 1.18, 95% CI 1.09, 1.29). The increased risk was highest for those with a history of opioid use disorder (aHR 1.94, 95% CI 1.09, 3.46) and also elevated for those with other substance use disorders (aHR 1.35, 95% CI 1.05, 1.73). Duration of the initial opioid prescription was independently associated with chronic opioid therapy, regardless of the estimated opioid daily dose.

CONCLUSIONS

History of mental health conditions and duration of the initial opioid prescription were associated with an increased risk of chronic opioid therapy among patients with RA.Key Points• Approximately a third of patients with RA are exposed to opioid analgesics.• Patients with RA and history of mental health disease, especially substance use disorders, who initiate opioid use have an increased risk of chronic opioid therapy.• This study provides insight in an underrepresented population of mainly male patients with RA.

Nasopharyngeal Pneumococcal Density during Asymptomatic Respiratory Virus Infection and Risk for Subsequent Acute Respiratory Illness

Increased nasopharyngeal pneumococcal (Streptococcus pneumoniae) colonization density has been associated with invasive pneumococcal disease, but factors that increase pneumococcal density are poorly understood. We evaluated pneumococcal densities in nasopharyngeal samples from asymptomatic young children from Peru and their association with subsequent acute respiratory illness (ARI). Total pneumococcal densities (encompassing all present serotypes) during asymptomatic periods were significantly higher when a respiratory virus was detected versus when no virus was detected (p<0.001). In adjusted analyses, increased pneumococcal density was significantly associated with the risk for a subsequent ARI (p<0.001), whereas asymptomatic viral detection alone was associated with lower risk for subsequent ARI. These findings suggest that interactions between viruses and pneumococci in the nasopharynx during asymptomatic periods might have a role in onset of subsequent ARI. The mechanisms for these interactions, along with other potentially associated host and environmental factors, and their role in ARI pathogenesis and pneumococcal transmission require further elucidation.

Effectiveness of 1, 2, and 3 Doses of Human Papillomavirus Vaccine Against High-Grade Cervical Lesions Positive for Human Papillomavirus 16 or 18

Before 2016, human papillomavirus (HPV) vaccination was recommended on a 3-dose schedule. However, many vaccine-eligible US females received fewer than 3 doses, which provided an opportunity to evaluate the real-world vaccine effectiveness (VE) of 1, 2, and 3 doses. We analyzed data on cervical intraepithelial neoplasia (CIN) grades 2-3 and adenocarcinoma in situ (designated CIN2+) from the HPV Vaccine Impact Monitoring Project (HPV-IMPACT; 2008-2014). Archived tissue from CIN2+ lesions was tested for 37 types of HPV. Women were classified by number of doses received ≥24 months before CIN2+ detection. Using a test-negative design, VE was estimated as 1 minus the adjusted odds ratio from a logistic regression model that compared vaccination history for women whose lesions tested positive for HPV-16/18 (vaccine-type cases) with that for women who had all other CIN2+ lesions (controls). Among 3,300 women with available data on CIN2+, typing results, and vaccine history, 1,561 (47%) were HPV-16/18-positive, 136 (4%) received 1 dose of HPV vaccine, 108 (3%) received 2 doses, and 325 (10%) received 3 doses. Adjusted odds ratios for vaccination with 1, 2, and 3 doses were 0.53 (95% confidence interval (CI): 0.37, 0.76; VE = 47%), 0.45 (95% CI: 0.30, 0.69; VE = 55%), and 0.26 (95% CI: 0.20, 0.35; VE = 74%), respectively. We found significant VE against vaccine-type CIN2+ after 3 doses of HPV vaccine and lower but significant VE with 1 or 2 doses.

Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America

Background: This document provides evidence-based clinical practice guidelines on the management of adult patients with community-acquired pneumonia.

Methods: A multidisciplinary panel conducted pragmatic systematic reviews of the relevant research and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations.

Results: The panel addressed 16 specific areas for recommendations spanning questions of diagnostic testing, determination of site of care, selection of initial empiric antibiotic therapy, and subsequent management decisions. Although some recommendations remain unchanged from the 2007 guideline, the availability of results from new therapeutic trials and epidemiological investigations led to revised recommendations for empiric treatment strategies and additional management decisions.

Conclusions: The panel formulated and provided the rationale for recommendations on selected diagnostic and treatment strategies for adult patients with community-acquired pneumonia.

Cervical adenocarcinoma in situ: Human papillomavirus types and incidence trends in five states, 2008-2015

Primary prevention through the use of human papillomavirus (HPV) vaccination is expected to impact both cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ (AIS). While CIN is well described, less is known about the epidemiology of AIS, a rare cervical precancer. We identified AIS and CIN grade 3 (CIN3) cases through population-based surveillance, and analyzed data on HPV types and incidence trends overall, and among women screened for cervical cancer. From 2008 to 2015, 470 AIS and 6,587 CIN3 cases were identified. The median age of women with AIS was older than those with CIN3 (35 vs. 31 years; p < 0.01). HPV16 was the most frequently detected type in both AIS and CIN3 (57% in AIS; 58% in CIN3), whereas HPV18 was the second most common type in AIS and less common in CIN3 (38% vs. 5%; p < 0.01). AIS lesions were more likely than CIN3 lesions to be positive for high-risk types targeted by the bivalent and quadrivalent vaccines (HPV16/18, 92% vs. 63%; p < 0.01), and 9-valent vaccine (HPV16/18/31/33/45/52/58, 95% vs. 87%; p < 0.01). AIS incidence rates decreased significantly in the 21-24 year age group (annual percent change [APC] overall: -22.1%, 95% CI: -33.9 to -8.2; APC among screened: -16.1%, 95% CI: -28.8 to -1.2), but did not decrease significantly in any older age group. This report on the largest number of genotyped AIS cases to date suggests an important opportunity for vaccine prevention of AIS, and is the first to document a decline in AIS incidence rates among young women during the vaccine era.

Evaluation of weight change and hypoglycaemia as mediators in the association between insulin use and death

AIM

To evaluate whether weight change or hypoglycaemia mediates the association between insulin use and death.

MATERIALS AND METHODS

In a retrospective cohort of veterans who filled a new prescription for metformin and added insulin or sulphonylurea (2001-2012), we assessed change in body mass index (BMI) and hypoglycaemia during the first 12 months of treatment intensification. Cox proportional hazards models compared the risk of death between treatment groups. Using the difference method, we estimated the indirect effect and proportion mediated through each mediator. A sensitivity analysis assessed mediators in the first 6 months of intensified therapy.

RESULTS

Among 28 892 patients surviving 12 months, deaths per 1000 person-years were 15.4 for insulin users and 12.9 for sulphonylurea users (HR 1.20, 95% CI 0.87, 1.64). Change in BMI and hypoglycaemia mediated 13% (-98, 98) and -1% (-37, 71) of this association, respectively. Among 30 214 patients surviving 6 months, deaths per 1000 person-years were 34.8 for insulin users and 21.3 for sulphonylurea users (HR 1.66, 95% CI 1.28, 2.15). Change in BMI and hypoglycaemia mediated 9% (1, 23) and 0% (-9, 4) of this association, respectively.

CONCLUSIONS

We observed an increased risk of death among metformin users intensifying treatment with insulin versus sulphonylurea and surviving 6 months of intensified therapy, but not among those surviving 12 months. This association was mediated in part by weight change.

A comparison of two algorithms to identify sudden cardiac deaths in computerized databases

PURPOSE

Two previously validated algorithms to identify sudden cardiac death using administrative data showed high positive predictive value. We evaluated the agreement between the algorithms using data from a common source population.

METHODS

We conducted a cross-sectional study to assess the percent agreement between deaths identified by two sudden cardiac death algorithms using Tennessee Medicaid and death certificate data from 2007 through 2014. The source population included all deceased patients aged 18 to 64 years with Medicaid enrollment in the 6 months prior to death. To identify sudden cardiac deaths, algorithm 1 used only hospital/emergency department (ED) claims from encounters at the time of death, and algorithm 2 required death certificates and used claims data for specific exclusion criteria.

RESULTS

We identified 34 107 deaths in the source population over the study period. The two algorithms identified 4372 potential sudden cardiac deaths: Algorithm 1 identified 3117 (71.3%) and algorithm 2 identified 1715 (39.2%), with 460 (10.5%) deaths identified by both algorithms. Of the deaths identified by algorithm 1, 1943 (62.3%) had an underlying cause of death not specified in algorithm 2. Of the deaths identified by algorithm 2, 1053 (61.4%) had no record of a hospital or ED encounter at the time of death, and 202 (11.8%) had a discharge diagnosis code not specified in algorithm 1.

CONCLUSIONS

We found low agreement between the two algorithms for identification of sudden cardiac deaths because of differences in sudden cardiac death definitions and data sources.

Association of Treatment With Metformin vs Sulfonylurea With Major Adverse Cardiovascular Events Among Patients With Diabetes and Reduced Kidney Function

IMPORTANCE

Before 2016, safety concerns limited metformin use in patients with kidney disease; however, the effectiveness of metformin on clinical outcomes in patients with reduced kidney function remains unknown.

OBJECTIVE

To compare major adverse cardiovascular events (MACE) among patients with diabetes and reduced kidney function who continued treatment with metformin or a sulfonylurea.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of US veterans receiving care within the national Veterans Health Administration, with data supplemented by linkage to Medicare, Medicaid, and National Death Index data from 2001 through 2016. There were 174 882 persistent new users of metformin and sulfonylureas who reached a reduced kidney function threshold (estimated glomerular filtration rate <60 mL/min/1.73 m2 or creatinine ≥1.4 mg/dL for women or ≥1.5 mg/dL for men). Patients were followed up from reduced kidney function threshold until MACE, treatment change, loss to follow-up, death, or study end (December 2016).

EXPOSURES

New users of metformin or sulfonylurea monotherapy who continued treatment with their glucose-lowering medication after reaching reduced kidney function.

MAIN OUTCOMES AND MEASURES

MACE included hospitalization for acute myocardial infarction, stroke, transient ischemic attack, or cardiovascular death. The analyses used propensity score weighting to compare the cause-specific hazard of MACE between treatments and estimate cumulative risk accounting for the competing risks of changing therapy or noncardiovascular death.

RESULTS

There were 67 749 metformin and 28 976 sulfonylurea persistent monotherapy users; the weighted cohort included 24 679 metformin and 24 799 sulfonylurea users (median age, 70 years [interquartile range {IQR}, 62.8-77.8]; 48 497 men [98%]; and 40 476 white individuals [82%], with median estimated glomerular filtration rate of 55.8 mL/min/1.73 m2 [IQR, 51.6-58.2] and hemoglobin A1c level of 6.6% [IQR, 6.1%-7.2%] at cohort entry). During follow-up (median, 1.0 year for metformin vs 1.2 years for sulfonylurea), there were 1048 MACE outcomes (23.0 per 1000 person-years) among metformin users and 1394 events (29.2 per 1000 person-years) among sulfonylurea users. The cause-specific adjusted hazard ratio of MACE for metformin was 0.80 (95% CI, 0.75-0.86) compared with sulfonylureas, yielding an adjusted rate difference of 5.8 (95% CI, 4.1-7.3) fewer events per 1000 person-years of metformin use compared with sulfonylurea use.

CONCLUSIONS AND RELEVANCE

Among patients with diabetes and reduced kidney function persisting with monotherapy, treatment with metformin, compared with a sulfonylurea, was associated with a lower risk of MACE.

Evaluation of Frailty as an Unmeasured Confounder in Observational Studies of Antidiabetic Medications

BACKGROUND

It is unknown whether observational studies evaluating the association between antidiabetic medications and mortality adequately account for frailty. Our objectives were to evaluate if frailty was a potential confounder in the relationship between antidiabetic medication regimen and mortality and how well administrative and clinical electronic health record (EHR) data account for frailty.

METHODS

We conducted a retrospective cohort study in a single Veterans Health Administration (VHA) healthcare system of 500 hospitalizations-the majority due to heart failure-of Veterans who received regular VHA care and initiated type 2 diabetes treatment from 2001 to 2008. We measured frailty using a modified frailty index (FI, >0.21 frail). We obtained antidiabetic medication regimen and time-to-death from administrative sources. We compared FI among patients on different antidiabetic regimens. Stepwise Cox proportional hazards regression estimated time-to-death by demographic, administrative, clinical EHR, and FI data.

RESULTS

Median FI was 0.22 (interquartile range 0.18, 0.27). Frailty differed across antidiabetic regimens (p < .001). An FI increase of 0.05 was associated with an increased risk of death (hazard ratio 1.45, 95% confidence interval 1.32, 1.60). Cox proportional hazards model for time-to-death including demographic, administrative, and clinical EHR data had a c-statistic of 0.70; adding FI showed marginal improvement (c-statistic 0.72).

CONCLUSIONS

Frailty was associated with antidiabetic regimen and death, and may confound that relationship. Demographic, administrative, and clinical EHR data, commonly used to balance differences among exposure groups, performed moderately well in assessing risk of death, with minimal gain from adding frailty. Study design and analytic techniques can help minimize potential confounding by frailty in observational studies.

Long-acting Opioid Use and the Risk of Serious Infections: A Retrospective Cohort Study

BACKGROUND

Although evidence from animal and human studies indicates opioid analgesics increase susceptibility to infections, it is unclear whether the risk varies by specific opioid. We compared the risk of serious infection among patients initiating long-acting opioid analgesics with and without previously reported immunosuppressive properties.

METHODS

We conducted a retrospective cohort study of Tennessee Medicaid enrollees age ≥18 years initiating long-acting opioids (1995-2015). Hospitalizations for serious infection were identified using validated coding algorithms. We used multivariable Poisson regression models to calculate adjusted incidence rate ratios (aIRR) and 95% confidence intervals (CI) to compare the infection risk among patients using long-acting opioids with known immunosuppressive properties (morphine, fentanyl, methadone) to the infection risk among patients using long-acting opioids without known immunosuppressive properties (oxycodone, oxymorphone, tramadol) accounting for demographics, opioid dose, comorbidities and pain conditions, medication use, frailty indicators, and healthcare encounter history using exposure propensity scores. We further compared users of individual long-acting opioids to long-acting morphine users (considered the prototypical immunosuppressive opioid).

RESULTS

Among the 61 240 patients initiating opioids with immunosuppressive properties and 22 811 patients initiating opioids without immunosuppressive properties, we identified 1906 serious infections. Nonimmunosuppressive opioid users had a lower rate of infections than immunosuppressive opioid users (aIRR:0.78 [CI: 0.66-0.91]). Among individual opioids, oxycodone users had a lower rate of infection than morphine users (aIRR:0.73 [CI: 0.60-0.89]). There were no significant differences in the infection risk between other opioids and morphine.

CONCLUSION

The risk of serious infections among long-acting opioid users varies by opioid type. Providers should carefully consider the risk of serious infections when making pain management decisions.

Trends in anogenital wart incidence among Tennessee Medicaid enrollees, 2006-2014: The impact of human papillomavirus vaccination

Introduction

Evidence of human papillomavirus (HPV) vaccine impact on anogenital warts (AGWs) by race or urbanicity in the US is lacking. We evaluated HPV vaccine impact in Tennessee by assessing AGW trends among Tennessee Medicaid (TennCare) enrollees aged 15–39 years from 2006-2014.

Methods

Persons with incident AGWs were identified using diagnosis/pharmacy codes from TennCare billing claims. We calculated sex-specific annual AGW incidence by age group, race, and urbanicity; estimated annual percent changes (APCs) using log-linear models; and performed pairwise comparisons by race and urbanicity.

Results

AGW incidence decreased among females aged 15–19 (APC = −10.6; P < 0.01) and 20–24 years (APC = −3.9; P = 0.02). Overall trends were similar between Whites and Blacks, and between those living in metropolitan statistical areas (MSAs) and non-MSAs. Rates among males aged 15–19 years began decreasing after 2010. Among enrollees aged 25–39 years, rates increased or were stable.

Conclusions

Following introduction of the HPV vaccine in 2006, AGWs decreased among age groups most likely to be vaccinated. The change in trend among young males after 2010 suggests early herd effects. Our findings indicate vaccine effects and support the importance of improving adherence to current vaccination recommendations for preventing AGWs and other HPV-related diseases.

Recent metformin adherence and the risk of hypoglycaemia in the year following intensification with a sulfonylurea

AIM

To evaluate whether recent low adherence to metformin monotherapy is associated with hypoglycaemia after addition of a sulfonylurea.

METHODS

We assembled a retrospective cohort of veterans who filled a new prescription for metformin between 2001 and 2011 and intensified treatment with a sulfonylurea after ≥1 year of metformin use. We calculated metformin adherence from pharmacy data using the proportion of days covered in the 180-day period before intensification. The primary outcome was hypoglycaemia, defined as a hospitalization or emergency department visit for hypoglycaemia or an outpatient blood glucose measurement <3.3 mmol/l in the year following intensification. Cox proportional hazards models were used to compare the risk of hypoglycaemia between participants with low (<80%) and high (≥80%) adherence. Adherence was also modelled as a continuous variable using restricted cubic splines.

RESULTS

Of 187 267 participants who initiated metformin monotherapy, 49 424 added a sulfonylurea after ≥1 year. The median (interquartile range) rate of treatment adherence was 87 (50-100)% and 43% had adherence <80%. Hypoglycaemia rates per 1000 person-years were 23.1 (95% CI 21.1-25.4) and 24.5 (95% CI 22.7-26.4) in participants with low and high adherence, respectively (adjusted hazard ratio 0.95, 95% CI 0.84-1.08). The risk of hypoglycaemia was similar across all levels of adherence when adherence was modelled as a continuous variable.

CONCLUSIONS

We found no evidence that past low adherence to metformin monotherapy was associated with hypoglycaemia after intensification with a sulfonylurea.

Impact of pneumococcal conjugate vaccines on hospitalizations for pneumonia in the United States

INTRODUCTION

Pneumonia is one of the leading causes of morbidity and mortality among children and older adults. Pneumococcal conjugate vaccines (PCVs) were introduced into the US routine infant vaccination schedule leading to substantial reductions of invasive pneumococcal diseases (IPD). PCV introduction also led to reductions in all-cause pneumonia among US children, though the indirect impact of PCVs on pneumonia in adults is difficult to quantify, especially due to the recent US recommendation for direct PCV use in older adults. Areas covered: We described the existing evidence for both the direct and indirect impact of PCVs on pneumonia among children and adults in the US since PCV introduction. Expert commentary: The introduction of PCVs into the US routine infant vaccination schedule led to important reductions in the burden of IPD and non-invasive pneumonia among vaccinated and unvaccinated populations. The impact of direct vaccination of older adults in the US since 2014, though difficult to quantify, is currently being evaluated. As pneumonia remains one of the leading causes of morbidity and mortality in the US, future evaluations of the direct and indirect effects of current and expanded valency PCVs in the US population are needed.

Accuracy of a composite event definition for hypoglycemia

PURPOSE

To evaluate the accuracy of a composite definition for the identification of hypoglycemia events that used both administrative claims and laboratory data in a cohort of patients.

METHODS

We reviewed medical records in a sample of presumed hypoglycemia events among patients who received care at the Veterans Health Administration Tennessee Valley Healthcare System in 2001 to 2012. A hypoglycemia event was defined as a hospitalization or emergency department visit judged by the treating clinician to be due to hypoglycemia, or an outpatient laboratory or point-of-care blood glucose measurement <60 mg/dL. Based on medical record review, each event was classified as true positive (severe, documented symptomatic, documented asymptomatic) or false positive (probable symptomatic, not hypoglycemia). The positive predictive values (PPV) of the individual event types (hospitalization, emergency department, and outpatient) were estimated.

RESULTS

Of 2250 events identified through the composite definition, 321 events (15 hospitalizations, 103 emergency department visits, and 203 outpatient events) were reviewed. The PPVs were 80% for hospitalization events, 48% for emergency department events, and 96% for outpatient events. The emergency department definition included a nonspecific diagnosis code for diabetic complications which captured many false positive events. Excluding this code from the definition improved the PPV for emergency department events to 70% and missed one true event.

CONCLUSIONS

Our composite definition for hypoglycemia performed moderately well in a cohort of Veterans. Further evaluation of the emergency department events may be needed.

Trends in Human Papillomavirus Vaccine Types 16 and 18 in Cervical Precancers, 2008-2014

BACKGROUND

The impact of human papillomavirus (HPV) vaccination has been observed in the United States through declining cervical precancer incidence in young women. To further evaluate vaccine impact, we described trends in HPV vaccine types 16/18 in cervical precancers, 2008-2014.

METHODS

We analyzed data from a 5-site, population-based surveillance system. Archived specimens from women age 18-39 years diagnosed with cervical intraepithelial neoplasia grades 2-3 or adenocarcinoma in situ (CIN2+) were tested for 37 HPV types. We described the proportion and estimated number of cases of CIN2+ by HPV-type groups over time. Trends in HPV16/18-positive CIN2+ were examined, overall and by vaccination status, age, histologic grade, and race/ethnicity, using Cochrane-Armitage tests.

RESULTS

In 10,206 cases, the proportion and estimated number of cases of HPV16/18-positive CIN2+ declined from 52.7% (1,235 cases) in 2008 to 44.1% (819 cases) in 2014 (P < 0.001). Declining trends in the proportion of HPV16/18-positive CIN2+ were observed among vaccinated (55.2%-33.3%, P < 0.001) and unvaccinated (51.0%-47.3%, P = 0.03) women; ages 18-20 (48.7%-18.8%, P = 0.02), 21-24 (53.8%-44.0%, P < 0.001), 25-29 (56.9%-42.4%, P < 0.001), and 30-34 (49.8%-45.8%, P = 0.04) years; CIN2 (40.8%-29.9%, P < 0.001) and CIN2/3 (61.8%-46.2%, P < 0.001); non-Hispanic white (59.5%-47.9%, P < 0.001) and non-Hispanic black (40.7%-26.5%, P < 0.001).

CONCLUSIONS

From 2008-2014, the proportion of HPV16/18-positive CIN2+ declined, with the greatest declines in vaccinated women; declines in unvaccinated women suggest herd protection.

IMPACT

The declining proportion of HPV16/18-positive CIN2+ provides additional evidence of vaccine impact in the United States.

988. Effectiveness of Seasonal Influenza Vaccines Against Influenza A(H3N2) Illness Among Children Aged &lt;18 Years, US Flu VE Network, 2010–2018

Background

Interim estimates of 2017–2018 influenza vaccine effectiveness (VE) against influenza A(H3N2)-related illness in the United States indicated better protection among young children than among older children and adolescents. We examined VE against influenza A(H3N2) illness during five A(H3N2)-predominant seasons from 2010–2011 through 2016–2017 to investigate differences between VE among younger vs. older children.

Methods

We analyzed data from 11,736 outpatients aged <18 years with medically attended acute respiratory illnesses enrolled at US Flu VE Network study sites during five influenza A(H3N2)-predominant seasons. Respiratory specimens from all enrollees were tested for influenza viruses using reverse transcription PCR. Children with documented receipt of the recommended number of doses of current season inactivated influenza vaccine at least 14 days before illness onset were considered fully vaccinated; partially vaccinated children and those who received live attenuated influenza vaccine were excluded. Vaccine effectiveness was estimated as 100 × (1 – adjusted odds ratio) from multivariable logistic regression adjusting for study site, age, sex, presence of high-risk medical conditions, and days from illness onset to enrollment comparing odds of vaccination among A(H3N2)-positive cases vs. influenza-negative controls.

Results

A total of 1,854 influenza A(H3N2) cases and 9,882 influenza-negative controls were included; 494 (28%) influenza A(H3N2) cases and 3,637 (41%) controls were fully vaccinated before illness onset. VE ranged from 26% (95% confidence interval [CI], −17% to 53%) to 60% (38%–75%) among children aged 6 months–4 years and from 9% (−16% to 29%) to 66% (37%–82%) among 5–17 year olds (figure). During 2012–2013 and 2014–2015, A(H3N2) VE estimates were significantly higher among younger compared with older children (P < 0.05); in other seasons before 2017–2018, A(H3N2) VE estimates were similar among younger and older children.

Conclusion

Higher VE against A(H3N2) viruses in younger vs. older children in some seasons suggests immunologic differences in response to vaccine components. Overall, inactivated influenza vaccine provided moderate protection against A(H3N2)-related illness among children.

Disclosures

M. L. Jackson, sanofi pasteur: Grant Investigator, Research support. L. A. Jackson, Novartis: Grant Investigator, Research support. R. K. Zimmerman, sanofi pasteur: Grant Investigator, Research support. Pfizer: Grant Investigator, Research support. Merck: Grant Investigator, Research support. M. P. Nowalk, Merck: Grant Investigator, Research support. Pfizer: Grant Investigator, Research support. M. R. Griffin, MedImmune: Grant Investigator, Research support. H. K. Talbot, sanofi pasteur: Investigator, Research grant. Gilead: Investigator, Research grant. MedImmune: Investigator, Research grant. Vaxinnate: Safety Board, none. Seqirus: Safety Board, none. J. J. Treanor, Novartis: Board Member and Consultant, Consulting fee.

Association of Prior Vaccination With Influenza Vaccine Effectiveness in Children Receiving Live Attenuated or Inactivated Vaccine

IMPORTANCE

Some studies have reported negative effects of prior-season influenza vaccination. Prior-season influenza vaccination effects on vaccine effectiveness (VE) in children are not well understood.

OBJECTIVE

To assess the association of prior-season influenza vaccination with subsequent VE in children aged 2 to 17 years.

DESIGN, SETTING, AND PARTICIPANTS

This multiseason, test-negative case-control study was conducted in outpatient clinics at 4 US sites among children aged 2 to 17 years with a medically attended febrile acute respiratory illness. Participants were recruited during the 2013-2014, 2014-2015, and 2015-2016 seasons when influenza circulated locally. Cases were children with influenza confirmed by reverse-transcription polymerase chain reaction. Test-negative control individuals were children with negative test results for influenza.

EXPOSURES

Vaccination history, including influenza vaccine type received in the enrollment season (live attenuated influenza vaccine [LAIV], inactivated influenza vaccine [IIV], or no vaccine) and season before enrollment (LAIV, IIV, or no vaccine), determined from medical records and immunization registries.

MAIN OUTCOMES AND MEASURES

LAIV and IIV effectiveness by influenza type and subtype (influenza A[H1N1]pdm09, influenza A[H3N2], or influenza B), estimated as 100 × (1 - odds ratio) in a logistic regression model with adjustment for potential confounders. Prior season vaccination associations were assessed with an interaction term.

RESULTS

Of 3369 children (1749 [52%] male; median age, 6.6 years [range, 2-17 years]) included in the analysis, 772 (23%) had a positive test result for influenza and 1674 (50%) were vaccinated in the enrollment season. Among LAIV recipients, VE against influenza A(H3N2) was higher among children vaccinated in both the enrollment and 1 prior season (50.3% [95% CI, 17.0% to 70.2%]) than among those without 1 prior season vaccination (-82.4% [95% CI, -267.5% to 9.5%], interaction P < .001). The effectiveness of LAIV against influenza A(H1N1)pdm09 was not associated with prior season vaccination among those with prior season vaccination (47.5% [95% CI, 11.4% to 68.9%]) and among those without prior season vaccination (7.8% [95% CI, -101.9% to 57.9%]) (interaction P = .37). Prior season vaccination was not associated with effectiveness of IIV against influenza A(H3N2) (38.7% [95% CI, 6.8% to 59.6%] among those with prior-season vaccination and 23.2% [95% CI, -38.3% to 57.4%] among those without prior-season vaccination, interaction P = .16) or with effectiveness of IIV against influenza A[H1N1]pdm09 (72.4% [95% CI, 56.0% to 82.7%] among those with prior season vaccination and 67.5% [95% CI, 32.1% to 84.4%] among those without prior season vaccination, interaction P = .93). Residual protection from prior season vaccination only (no vaccination in the enrollment season) was observed for influenza B (LAIV: 60.0% [95% CI, 36.8% to 74.7%]; IIV: 60.0% [36.9% to 74.6%]). Similar results were observed in analyses that included repeated vaccination in 2 and 3 prior seasons.

CONCLUSIONS AND RELEVANCE

Influenza VE varied by influenza type and subtype and vaccine type, but prior-season vaccination was not associated with reduced VE. These findings support current recommendations for annual influenza vaccination of children.

Metformin use and incidence cancer risk: evidence for a selective protective effect against liver cancer

PURPOSE

Several observational studies suggest that metformin reduces incidence cancer risk; however, many of these studies suffer from time-related biases and several cancer outcomes have not been investigated due to small sample sizes.

METHODS

We constructed a propensity score-matched retrospective cohort of 84,434 veterans newly prescribed metformin or a sulfonylurea as monotherapy. We used Cox proportional hazard regression to assess the association between metformin use compared to sulfonylurea use and incidence cancer risk for 10 solid tumors. We adjusted for clinical covariates including hemoglobin A1C, antihypertensive and lipid-lowering medications, and body mass index. Incidence cancers were defined by ICD-9-CM codes.

RESULTS

Among 42,217 new metformin users and 42,217 matched-new sulfonylurea users, we identified 2,575 incidence cancers. Metformin was inversely associated with liver cancer (adjusted hazard ratio [aHR] = 0.44, 95% CI 0.31, 0.64) compared to sulfonylurea. We found no association between metformin use and risk of incidence bladder, breast, colorectal, esophageal, gastric, lung, pancreatic, prostate, or renal cancer when compared to sulfonylurea use.

CONCLUSIONS

In this large cohort study that accounted for time-related biases, we observed no association between the use of metformin and most cancers; however, we found a strong inverse association between metformin and liver cancer. Randomized trials of metformin for prevention of liver cancer would be useful to verify these observations.

Trends in High-Grade Cervical Cancer Precursors in the Human Papillomavirus Vaccine Era

INTRODUCTION

The 2006 introduction of human papillomavirus vaccine targeted against genotypes 6, 11, 16, and 18 should result in decreased cervical dysplasia in vaccinated women. However, new cervical cancer guidelines to increase screening intervals complicate interpretation of trends. The hypothesis is that cervical dysplasia would decrease only in young vaccine-eligible women, and not older women.

METHODS

The authors identified Davidson County, Tennessee, women aged 18-39 years with cervical intraepithelial neoplasia (CIN) grade 2 or greater and adenocarcinoma in situ, denoted as CIN2+, through pathology reports from laboratories serving this population. Biopsy specimens for human papillomavirus genotyping were collected. Trends in CIN2+ rates and associated human papillomavirus genotypes, 2008 through 2013, were examined.

RESULTS

The authors identified 2,031 women with CIN2+. Rates of CIN2+ fell from 188.9 to 58.7 per 100,000 women aged 18-20 years (annual percentage change= -24.2, 95% CI= -41.4, -2.1) and from 495.6 to 332.4 per 100,000 women aged 21-24 years (annual percentage change= -10.2%, 95% CI= -16.3, -3.4). There was no significant change in CIN2+ rates for women aged 25-29 or 30-39 years. In biopsy specimens from 1,319 of 2,031 (65%) women, at least one human papillomavirus genotype was identified in 1,270 (96%). The prevalence of at least one of four vaccine human papillomavirus genotypes (6, 11, 16, and 18) declined from 59% in 2008 to 52% in 2013 (p=0.003).

CONCLUSIONS

Diagnosis of CIN2+ decreased in women aged 18-24 years, but not in older women. Both changes in screening and human papillomavirus vaccination could have contributed to the decline of CIN2+ in young women.

Influence of Birth Cohort on Effectiveness of 2015-2016 Influenza Vaccine Against Medically Attended Illness Due to 2009 Pandemic Influenza A(H1N1) Virus in the United States

Background

The effectiveness of influenza vaccine during 2015-2016 was reduced in some age groups as compared to that in previous 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09 virus)-predominant seasons. We hypothesized that the age at first exposure to specific influenza A(H1N1) viruses could influence vaccine effectiveness (VE).

Methods

We estimated the effectiveness of influenza vaccine against polymerase chain reaction-confirmed influenza A(H1N1)pdm09-associated medically attended illness from the 2010-2011 season through the 2015-2016 season, according to patient birth cohort using data from the Influenza Vaccine Effectiveness Network. Birth cohorts were defined a priori on the basis of likely immunologic priming with groups of influenza A(H1N1) viruses that circulated during 1918-2015. VE was calculated as 100 × [1 - adjusted odds ratio] from logistic regression models comparing the odds of vaccination among influenza virus-positive versus influenza test-negative patients.

Results

A total of 2115 A(H1N1)pdm09 virus-positive and 14 696 influenza virus-negative patients aged ≥6 months were included. VE was 61% (95% confidence interval [CI], 56%-66%) against A(H1N1)pdm09-associated illness during the 2010-2011 through 2013-2014 seasons, compared with 47% (95% CI, 36%-56%) during 2015-2016. During 2015-2016, A(H1N1)pdm09-specific VE was 22% (95% CI, -7%-43%) among adults born during 1958-1979 versus 61% (95% CI, 54%-66%) for all other birth cohorts combined.

Conclusion

Findings suggest an association between reduced VE against influenza A(H1N1)pdm09-related illness during 2015-2016 and early exposure to specific influenza A(H1N1) viruses.

Validation of discharge diagnosis codes to identify serious infections among middle age and older adults

OBJECTIVES

Hospitalisations for serious infections are common among middle age and older adults and frequently used as study outcomes. Yet, few studies have evaluated the performance of diagnosis codes to identify serious infections in this population. We sought to determine the positive predictive value (PPV) of diagnosis codes for identifying hospitalisations due to serious infections among middle age and older adults.

SETTING AND PARTICIPANTS

We identified hospitalisations for possible infection among adults >=50 years enrolled in the Tennessee Medicaid healthcare programme (2008-2012) using International Classifications of Diseases, Ninth Revision diagnosis codes for pneumonia, meningitis/encephalitis, bacteraemia/sepsis, cellulitis/soft-tissue infections, endocarditis, pyelonephritis and septic arthritis/osteomyelitis.

DESIGN

Medical records were systematically obtained from hospitals randomly selected from a stratified sampling framework based on geographical region and hospital discharge volume.

MEASURES

Two trained clinical reviewers used a standardised extraction form to abstract information from medical records. Predefined algorithms served as reference to adjudicate confirmed infection-specific hospitalisations. We calculated the PPV of diagnosis codes using confirmed hospitalisations as reference. Sensitivity analyses determined the robustness of the PPV to definitions that required radiological or microbiological confirmation. We also determined inter-rater reliability between reviewers.

RESULTS

The PPV of diagnosis codes for hospitalisations for infection (n=716) was 90.2% (95% CI 87.8% to 92.2%). The PPV was highest for pneumonia (96.5% (95% CI 93.9% to 98.0%)) and cellulitis (91.1% (95% CI 84.7% to 94.9%)), and lowest for meningitis/encephalitis (50.0% (95% CI 23.7% to 76.3%)). The adjudication reliability was excellent (92.7% agreement; first agreement coefficient: 0.91). The overall PPV was lower when requiring microbiological confirmation (45%) and when requiring radiological confirmation for pneumonia (79%).

CONCLUSIONS

Discharge diagnosis codes have a high PPV for identifying hospitalisations for common, serious infections among middle age and older adults. PPV estimates for rare infections were imprecise.

Clinical Features of Human Metapneumovirus Infection in Ambulatory Children Aged 5-13 Years

We detected human metapneumovirus (HMPV) in 54 (5%) of 1055 children aged 5 to 13 years with acute respiratory illness (ARI) identified by outpatient and emergency department surveillance between November and May 2003-2009. Its clinical features were similar to those of HMPV-negative ARI, except a diagnosis of pneumonia was more likely (13% vs 4%, respectively; P = .005) and a diagnosis of pharyngitis (7% vs 24%, respectively; P = .005) was less likely in patients with HMPV- positive ARI than those with HMPV-negative ARI.