Associations between interpregnancy interval and preterm birth by previous preterm birth status in four high-income countries: a cohort study

OBJECTIVE

To investigate the effect of interpregnancy interval (IPI) on preterm birth (PTB) according to whether the previous birth was preterm or term.

DESIGN

Cohort study.

SETTING

USA (California), Australia, Finland, Norway (1980-2017).

POPULATION

Women who gave birth to first and second (n = 3 213 855) singleton livebirths.

METHODS

Odds ratios (ORs) for PTB according to IPIs were modelled using logistic regression with prognostic score stratification for potential confounders. Within-site ORs were pooled by random effects meta-analysis.

OUTCOME MEASURE

PTB (gestational age <37 weeks).

RESULTS

Absolute risk of PTB for each IPI was 3-6% after a previous term birth and 17-22% after previous PTB. ORs for PTB differed between previous term and preterm births in all countries (P-for-interaction ≤ 0.001). For women with a previous term birth, pooled ORs were increased for IPI <6 months (OR 1.50, 95% CI 1.43-1.58); 6-11 months (OR 1.10, 95% CI 1.04-1.16); 24-59 months (OR 1.16, 95% CI 1.13-1.18); and ≥ 60 months (OR 1.72, 95%CI 1.60-1.86), compared with 18-23 months. For previous PTB, ORs were increased for <6 months (OR 1.30, 95% CI 1.18-1.42) and ≥60 months (OR 1.29, 95% CI 1.17-1.42), but were less than ORs among women with a previous term birth (P < 0.05).

CONCLUSIONS

Associations between IPI and PTB are modified by whether or not the previous pregnancy was preterm. ORs for short and long IPIs were higher among women with a previous term birth than a previous PTB, which for short IPI is consistent with the maternal depletion hypothesis. Given the high risk of recurrence and assuming a causal association between IPI and PTB, IPI remains a potentially modifiable risk factor for women with previous PTB.

TWEETABLE ABSTRACT

Short versus long interpregnancy intervals associated with higher ORs for preterm birth (PTB) after a previous PTB.

Outcomes of Same-Day Orthopedic Surgery: Are Spine Patients More Likely to Have Optimal Immediate Recovery From Outpatient Procedures?

BACKGROUND

Spinal surgery is associated with an inherently elevated risk profile, and thus far there has been limited discussion about how these outpatient spine patients are benefiting from these same-day procedures against other typical outpatient orthopedic surgeries.

METHODS

Orthopedic patients who received either inpatient or outpatient surgery were isolated in the American College of Surgeons National Surgical Quality of Improvement Program (2005-2016). Patients were stratified by type of orthopedic surgery received (spine, knee, ankle, shoulder, or hip). Mean comparisons and chi-squared tests assessed basic demographics. Perioperative complications were analyzed via regression analyses in regard to their principal inpatient or outpatient orthopedic surgery received.

RESULTS

This study included 729 480 surgical patients: 32.5% received spinal surgery, 36.5% knee, 24.1% hip, 4.9% shoulder, and 1.7%ankle. Of those who received a spinal procedure, 74.7% were inpatients (IN), and 25.3% were outpatients (OUT): knee: 96.1% IN, 3.9% OUT; hip:98.9% IN, 1.1% OUT; ankle: 29% IN, 71% OUT; and shoulder: 52.6% IN, 47.6% OUT. Hip patients were the oldest, and knee patients had the highest body mass index out of the orthopedic groups (P < .00). Spine IN patients experienced more complications than the other orthopedic groups and had the lowest OUT complications(both P < .05). This same trend of having higher IN complications than OUT complications was identified for hip, shoulder, and knee. However, ankle procedures had greater OUT procedure complications than IN (P < .05). After controlling for age, body mass index, and Charlson Comorbidity Index, IN procedures, such as knee, hip, spine, and shoulder, were significantly associated with experiencing postoperative complications. From 2006 to 2016, IN and OUT surgeries were significantly different among complications experienced for all of the orthopedic groups (P < .05) with complications decreasing for IN and OUT patients by 2016.

CONCLUSIONS

Over the past decade, spine surgery has decreased in complications for IN and OUT procedures along with IN/OUT knee, ankle, hip, and shoulder procedures, reflecting greater tolerance for risk in an outpatient setting.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Despite the increase in riskier spine procedures, complications have decreased over the years. Surgeons should aim to continue to decrease inpatient spine complications to the level of other orthopedic surgeries.

Tele-rehabilitation for people with dementia in the COVID-19 pandemic: A case-study

Introduction

The Promoting Activity, Independence and Stability in Early Dementia (PrAISED) is delivering an exercise programme for people with dementia. The Lincolnshire partnership NHS foundation Trust successfully delivered PrAISED through a video-calling platform during the COVID-19 pandemic.

Objectives

This qualitative case-study identified participants that video delivery worked for, and highlighted its benefits and challenges.

Methods

Interviews were conducted with participants with dementia, caregivers and therapists, and analysed through thematic analysis.

Results

Video delivery worked best when participants had a supporting carer, when therapists showed enthusiasm and had an established rapport with the client. Benefits included time-efficiency of sessions, enhancing participants’ motivation, caregivers’ dementia awareness and therapists’ creativity. Limitations included users’ poor IT skills and resources.

Conclusions

The COVID-19 pandemic required innovative ways of delivering rehabilitation. This study supports that people with dementia can use tele rehab, but success is reliant on having a caregiver and an enthusiastic and known therapist.

Cancer prevention through weight control-where are we in 2020?

Growing data from epidemiological studies highlight the association between excess body fat and cancer incidence, but good indicative evidence demonstrates that intentional weight loss, as well as increasing physical activity, offers much promise as a cost-effective approach for reducing the cancer burden. However, clear gaps remain in our understanding of how changes in body fat or levels of physical activity are mechanistically linked to cancer, and the magnitude of their impact on cancer risk. It is important to investigate the causal link between programmes that successfully achieve short-term modest weight loss followed by weight-loss maintenance and cancer incidence. The longer-term impact of weight loss and duration of overweight and obesity on risk reduction also need to be fully considered in trial design. These gaps in knowledge need to be urgently addressed to expedite the development and implementation of future cancer-control strategies. Comprehensive approaches to trial design, Mendelian randomisation studies and data-linkage opportunities offer real possibilities to tackle current research gaps. In this paper, we set out the case for why non-pharmacological weight-management trials are urgently needed to support cancer-risk reduction and help control the growing global burden of cancer.

Differences in 30-day complications associated with total ankle arthroplasty and ankle arthrodesis: A matched cohort study

BACKGROUND

The objective of this study was to identify whether total ankle arthroplasty (TAA) was associated with greater risk for 30-day complications and/or greater financial burden in comparison to ankle arthrodesis (AA).

METHODS

The PearlDiver Patient Records Database was queried to identify all patients who underwent an arthroscopic/open AA or TAA from 2006 to 2013. The two cohorts were then matched in a 1:1 manner to control for comorbidities and demographics. Postoperative complications were compared between the two cohorts, in addition to the associated costs with respect to each procedure.

RESULTS

No significant differences in risk for postoperative complications were noted between the two procedures with the numbers available. Significant differences were demonstrated in total length of hospital stay (LOS), with a mean of 2.13 days for the TAA cohort and 2.42 days for the AA cohort (p < 0.001). Higher mean total hospital costs were noted for TAA (x¯ = $62,416.62) compared to AA (x¯ = $37,737.43, p < 0.001); however, TAA was associated with a higher mean total reimbursement (x¯ = $12,254.43) than AA (x¯ = $7915.72, p < 0.001).

CONCLUSION

With no notable differences in 30-day complication rates, TAA remains a viable alternative to AA in the appropriately selected patient and provides the ability to preserve tibiotalar motion resulting in superior functional scores. Additionally, TAA demonstrated higher total costs to implant, but also greater reimbursement, in line with the recent literature suggesting TAA to be a cost-effective alternative to AA.

LEVEL OF EVIDENCE

III Retrospective study.

Rheumatoid Arthritis Increases Risk of Medical Complications Following Posterior Lumbar Fusion

BACKGROUND

Rheumatoid arthritis (RA) is a systemic disease with prominent musculoskeletal manifestations that is associated with increased morbidity and mortality in patients undergoing cervical spine surgery; however, few studies have specifically examined postoperative outcomes in patients with RA following lumbar surgery. The aim of this study was to evaluate whether patients with RA who underwent posterior lumbar fusion experienced increased postoperative complications and economic burden compared with patients without RA.

METHODS

Patients <85 years old who underwent elective 1- or 2-level instrumented posterior lumbar fusion for degenerative lumbar pathology between 2006 and 2012 were identified in the Medicare insurance claims database. Same-day revisions and cases for spinal infection, malignancy, and trauma were excluded. The resulting cohort was divided into patients with RA before fusion and patients without RA (controls). All outcomes of interest were compared using multivariate regression. Reoperation-free survival at 1- and 2-year follow-up was analyzed used log-rank test. Significance was defined as P < 0.05.

RESULTS

RA patients had significantly higher risk of 90-day readmission (odds ratio [OR] = 1.27, P < 0.001), thromboembolic events (OR = 1.39, P = 0.010), sepsis (OR = 2.32, P < 0.001), pneumonia (OR = 1.57, P = 0.001), and wound complications (OR = 1.41, P < 0.001). Reoperation-free survival was significantly lower in RA patients at 2-year follow-up (90.4% vs. 92.4%, P < 0.001). Following adjusted regression, RA independently contributed to a $1491 increase in additional 90-day costs (P < 0.001).

CONCLUSIONS

Preexisting RA may increase risk for short-term postoperative medical complications following posterior lumbar fusion, specifically infectious events. In addition, patients with RA have higher rates of subsequent reoperation following index surgery. Patients with RA be should counseled regarding these risks.

Abstract 5466: Robust detection of sequencing batch effects in RNA through low dimensional embedding with subtype-matched reference samples

Laboratories conducting high volumes of RNA sequencing must be extremely wary of technical batch effects if samples are to be compared across extended time periods, which is imperative for the most well-powered analyses of cancer transcriptomes. Changes in reagents, protocols, or technologies used in nucleic acid extraction, library preparation, and sequencing can alter transcriptomes in ways that invalidate or complicate comparisons of samples from different batches, necessitating continuous monitoring. This monitoring can be particularly difficult when analyzing samples from distinct tissue sites as tumor type is the major biological determinant of transcriptome variance in cancer. Brain and liver cancer transcriptomes, for example, are expected to differ so drastically that their comparison is not informative for batch effect detection. Detection methods must also be robust to disparate batch effects that can manifest as minor changes in expression among many genes or major changes in a subset of genes making ad hoc detection unfeasible. To overcome these challenges, we developed MaCoBED (matched cohort batch effect detection), a novel method that evaluates technical batch effects in a set of transcriptome samples (e.g., a flow cell) by pooling them with a set of validated reference samples matched by cancer type and tissue site. This pooled set of transcriptomes is then subjected to low-dimensional embedding using Uniform Manifold Approximation and Projection (UMAP), and each component is tested for deviation from the reference set using a Wilcox test. Matching new and legacy samples by cancer type and tissue site ensures that any differences in UMAP clustering are not driven by known biological contributions. We found that UMAP was preferable to Principal Components Analysis (PCA). UMAP can capture variability in just two dimensions, accentuating modest but consistent transcriptome differences among batches that would otherwise be manifested among multiple minor principal components, making batch effects more obvious and readily detectable. This approach was able to detect a number of simulated batch effects with high specificity and sensitivity relative to randomly sampled validated legacy samples. Thus, we propose MaCoBED as a simple and rapid approach for batch effect monitoring of high-throughput RNA sequencing datasets that is versatile in detecting distinct kinds of batch effects, easily automatable, readily interpretable upon visualization, and extensible to small or large batch sizes.

Citation Format: Joshua Drews, Joshua Bell, Wesley Munson, Saksham Saini, Benjamin Leibowitz, Jackson Michuda, Calvin McCarter, Lee Langer, Catherine Igartua, Kevin White. Robust detection of sequencing batch effects in RNA through low dimensional embedding with subtype-matched reference samples [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5466.

A Radon Background-subtraction Algorithm for Electronic Personal Dosimeters

Many first responders are outfitted with electronic personal dosimeters to recognize and be alerted to radiological hazards during their response operations. These dosimeters provide invaluable measurement data for force protection, allowing the first responder to assess a response situation and take protective measures for themselves and other individuals involved based on instrument readings of dose rate or cumulative dose. However, capabilities of common electronic personal dosimeters to identify and distinguish various contributions to the instrument reading, in particular from natural radiological sources, are rather limited. An algorithm has been developed for two-channel electronic personal dosimeters that quantifies the signal contribution from radon progeny and allows for background subtraction from radon and radon progeny in the instrument reading. This algorithm will be particularly useful in operational scenarios where first responders may be subject to rapidly changing levels of natural background radiation, which could mimic the presence of anthropogenic sources of ionizing radiation.

Outcomes Following Revision Joint Arthroplasty Among Hemodialysis-Dependent Patients

BACKGROUND

Hemodialysis (HD) dependence is known to impact the integrity of bone and has long been associated with metabolic bone disease and other adverse events postoperatively. The aim of this study is to analyze postoperative outcomes following revision hip and knee arthroplasty in hemodialysis-dependent (HDD) patients and to characterize the common indications for revision procedures among this patient population.

METHODS

A total of 1779 HDD patients who underwent a revision joint arthroplasty (930 revision total knee arthroplasty [TKA] and 849 revision total hip arthroplasty [THA]) between 2005 and 2014 were identified from a retrospective database review. Our resulting study groups of revision TKA and THA HDD patients were compared to their respective matched control groups for hospital length of stay (LOS), 90-day mean total cost, hospital readmission, and other major medical and surgical complications.

RESULTS

HD was significantly associated with increased LOS (7.7 ± 8.3 vs 4.8 ± 4.5; P < .001), mean 90-day total cost ($47,478 ± $33,413 vs $24,286 ± $21,472; P < .001), hospital readmission (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.96-2.58; P < .001), septicemia (OR, 3.18; 95% CI, 2.70-3.74; P < .001), postoperative infection (OR, 1.72; 95% CI, 1.50-1.98; P < .001), and mortality (OR, 3.99; 95% CI, 3.12-5.06; P < .001) following revision TKA. Among revision THA patients, HD was associated with increased LOS (9.4 ± 9.5 vs 5.7 ± 5.7; P < .001), mean 90-day total cost ($40,182 ± $27,082 vs $26,519 ± $22,856; P < .001), hospital readmission (OR, 2.33; 95% CI, 2.02-2.68; P < .001), septicemia (OR, 3.61; 95% CI, 3.05-4.27; P < .001), and mortality (OR, 3.55; 95% CI, 2.86-4.37; P < .001).

CONCLUSION

HD remains a significant risk factor for increased LOS, mean total cost, hospital readmission, septicemia, and mortality following revision joint arthroplasty.

Opioids and Spinal Cord Stimulators: Pre- and Postoperative Opioid Use Patterns and Predictors of Prolonged Postoperative Opioid Use

Objective

The aim of the study was to compare trends and differences in preoperative and prolonged postoperative opioid use following spinal cord stimulator (SCS) implantation and to determine factors associated with prolonged postoperative opioid use.

Methods

A database of private-payer insurance records was queried to identify patients who underwent a primary paddle lead SCS placement via a laminectomy (CPT-C3655) from 2008–2015. Our resulting cohort was stratified into those with prolonged postoperative opioid use, opioid use between 3- and 6-month postoperation, and those without. Multivariate logistic regression was used to determine the effect preoperative opioid use and other factors of interest had on prolonged postoperative opioid use. Subgroup analysis was performed on preoperative opioid users to further quantify the effect of differing magnitudes of preoperative opioid use.

Results

A total of 2,374 patients who underwent SCS placement were identified. Of all patients, 1,890 patients (79.6%) were identified as having prolonged narcotic use. Annual rates of preoperative (p = 0.023) and prolonged postoperative narcotic use (p < 0.001) decreased over the study period. Significant independent predictors of prolonged postoperative opioid use were age < 65 years (odds ratio [OR], 1.52; p = 0.004), male sex (OR, 1.33; p = 0.037), preoperative anxiolytic (OR, 1.55; p = 0.004) and muscle relaxant (OR, 1.42; p = 0.033), and narcotic use (OR, 15.04; p < 0.001). Increased number of preoperative narcotic prescriptions correlated with increased odds of prolonged postoperative use.

Conclusion

Patients with greater number of preoperative opioid prescriptions may not attain the same benefit from SCSs as patients with less opioid use. The most significant predictor of prolonged narcotic use was preoperative opioid use.

Demographic Trends in Paddle Lead Spinal Cord Stimulator Placement: Private Insurance and Medicare Beneficiaries

Objective

Although spinal cord stimulators (SCS) continue to gain acceptance as a viable nonpharmacologic option for the treatment of chronic back pain, recent trends are not well established. The aim of this study was to evaluate recent overall demographic and regional trends in paddle lead SCS placement and to determine if differences in trends exist between private-payer and Medicare beneficiaries.

Methods

A retrospective review of Medicare and private-payer insurance records from 2007–2014 was performed to identify patients who underwent a primary paddle lead SCS placement via a laminectomy (CPT-63655). Each study cohort was queried to determine the annual rate of SCS placements and demographic characteristics. Yearly SCS implantation rates within the study cohorts were adjusted per 100,000 beneficiaries. A chi-square analysis was used to compare changes in annual rates.

Results

A total of 31,352 Medicare and 2,935 private-payer patients were identified from 2007 to 2014. Paddle lead SCS placements ranged from 5.9 to 17.5 (p < 0.001), 1.9 to 5.9 (p < 0.001), and 5.2 to 14.5 (p < 0.001) placements per 100,000 Medicare, private-payer, and overall beneficiaries respectively from 2007 to 2014. SCS placements peaked in 2013 with 19.6, 7.1, and 16.8 placements per 100,000 Medicare, private-payer, and overall patients.

Conclusion

There was an overall increase in the annual rate of SCS placements from 2007 to 2014. Paddle lead SCS placements peaked in 2013 for Medicare, private-payer, and overall beneficiaries. The highest incidence of implantation was in the Southern region of the United States and among females. Yearly adjusted rates of SCSs were higher among Medicare patients at all time points.

Determination of Selenium in Feeds and Premixes: Collaborative Study

A total of 17 laboratories participated in a collaborative study for the determination of selenium in feeds and premixes using either a fluorometric or a continuous hydride generation atomic absorption (HGAA) method. Each collaborator analyzed 16 blind duplicate samples of feed and premixes from various feed manufacturers. The amount of Se in these materials ranged from 0.2 to 5500 μg/g. Six laboratories used only the fluorometric procedure, 8 laboratories used only the hydride generation atomic absorption procedure, and 3 laboratories used both procedures. One laboratory in the fluorometric study and 3 laboratories in the HGAA study were initially excluded because of invalid data. Poor agreement between the blind duplicates indicated probable sample interchange and/or dilution error. The data from 8 laboratories were submitted to statistical analysis, including data from 2 laboratories participating in both studies. The repeatability standard deviation (RSDr) for samples analyzed by the fluorometric procedure ranged from 5.9 to 33%, and the reproducibility standard deviation (RSDR) ranged from 12 to 33%. RSDf for samples analyzed by HGAA ranged from 2.8 to 18%, and RSDR ranged from 4.0 to 36%. Both fluorometric and continuous hydride generation atomic absorption methods for the determination of Se in feeds and premixes have been adopted first action by AOAC INTERNATIONAL.