Internal Comparison Group Research Articles

Anticoagulation in embolic acute limb ischaemia-an observational study.

The management of embolic acute limb ischaemia commonly involves determining aetiology and performing emergency invasive procedures. This detailed study aimed to determine the impact of manipulation of anticoagulation in the aetiology of emboli in acute limb ischaemia and determine the efficacy of primary anticoagulation therapy vs. invasive interventions. Material and methods: Data collection was conducted at a single institution on a cohort of patients presenting consecutively with embolic acute limb ischaemia over one year. Two groups were compared, one receiving anticoagulation as primary therapy with those undergoing invasive treatment as the internal comparison group. Results: A likely haematological causation was identified in 22 of 38 presentations, related to interruption of anticoagulation in cardiac conditions, the majority atrial fibrillation (n=12), or hypercoagulable states (n=10). Limb salvage was pursued in 36 patients employing anticoagulation (n=19) or surgical embolectomy (n=17) as the primary therapy in upper and lower limbs (n=17 vs n=19 respectively). Despite delays often well beyond six hours and a range of ischaemic severity in both groups, 35 of 36 patients achieved full or substantive restoration of function with improved perfusion. Regarding anatomical distribution of arterial disease and therapy, three patients with multi-level disease proceeded to embolectomy following anticoagulation. Embolectomy was undertaken most often for proximal emboli and more profound paralysis. Conclusions: Anticoagulation and coagulopathy are commonly implicated in the aetiology of arterial emboli, with omission of effective anticoagulation in atrial fibrillation being associated in almost 1/3 of presentations. Whilst more profound limb paralysis and proximal or multi-level disease tended to be managed surgically, primary anticoagulation therapy alone or with a secondary embolectomy was effective across the spectrum of ischaemia severity and despite significant delays beyond guideline recommendations.

Role of TBX20 Truncating Variants in Dilated Cardiomyopathy and Left Ventricular Noncompaction.

Less than 40% of patients with dilated cardiomyopathy (DCM) have a pathogenic/likely pathogenic genetic variant identified. TBX20 has been linked to congenital heart defects; although an association with left ventricular noncompaction (LVNC) and DCM has been proposed, it is still considered a gene with limited evidence for these phenotypes. This study sought to investigate the association between the TBX20 truncating variant (TBX20tv) and DCM/LVNC. TBX20 was sequenced by next-generation sequencing in 7463 unrelated probands with a diagnosis of DCM or LVNC, 22 773 probands of an internal comparison group (hypertrophic cardiomyopathy, channelopathies, or aortic diseases), and 124 098 external controls (individuals from the gnomAD database). Enrichment of TBX20tv in DCM/LVNC was calculated, cosegregation was determined in selected families, and clinical characteristics and outcomes were analyzed in carriers. TBX20tv was enriched in DCM/LVNC (24/7463; 0.32%) compared with internal (1/22 773; 0.004%) and external comparison groups (4/124 098; 0.003%), with odds ratios of 73.23 (95% CI, 9.90-541.45; P<0.0001) and 99.76 (95% CI, 34.60-287.62; P<0.0001), respectively. TBX20tv was cosegregated with DCM/LVNC phenotype in 21 families for a combined logarythm of the odds score of 4.53 (strong linkage). Among 57 individuals with TBX20tv (49.1% men; mean age, 35.9±20.8 years), 41 (71.9%) exhibited DCM/LVNC, of whom 14 (34.1%) had also congenital heart defects. After a median follow-up of 6.9 (95% CI, 25-75:3.6-14.5) years, 9.7% of patients with DCM/LVNC had end-stage heart failure events and 4.8% experienced malignant ventricular arrhythmias. TBX20tv is associated with DCM/LVNC; congenital heart defect is also present in around one-third of cases. TBX20tv-associated DCM/LVNC is characterized by a nonaggressive phenotype, with a low incidence of major cardiovascular events. TBX20 should be considered a definitive gene for DCM and LVNC and routinely included in genetic testing panels for these phenotypes.

Mortality of older construction and craft workers employed at Department of Energy (DOE) nuclear sites: Follow-up through 2021.

To determine if construction and trades workers formerly employed at US Department of Energy (DOE) nuclear weapons sites are at significant risk for occupational diseases, we studied the mortality experience of participants in the Building Trades National Medical Screening Program (BTMed). The cohort included 26,922 participants enrolled between 1998 and 2021 and 8367 deaths. Standardized mortality ratios were calculated based on US death rates. Cox models compared construction workers (n = 22,747; 7487 deaths) to two nonconstruction subpopulations: administrative, scientific and security workers (n = 1894; 330 deaths), and all other nonconstruction workers (n = 2218; 550 deaths). Mortality was elevated for all causes, all cancers, cancers of the trachea, bronchus, lung, kidneys, and lymphatic and hematopoietic system, mesothelioma, chronic obstructive pulmonary disease (COPD), asbestosis, transportation injuries, and other injuries, particularly accidental poisonings. There were 167 deaths from coronavirus disease 2019 (COVID-19), which was lower than expected using US death rates. Overall cause-specific mortality was significantly higher among construction workers than for internal comparison groups. Construction workers employed at DOE sites have a significantly increased risk for occupational illnesses. Apart from COVID-19 deaths, this update: (1) found that mortality among construction workers is significantly elevated compared to the US population and significantly higher than in the internal comparison populations, and (2) confirmed excess risk for these workers for first employment after 1990. Cancer mortality risks are similar to the cancers identified for DOE compensation from radiation exposures. The high lung cancer risk supports the value of early lung cancer detection. Continued medical surveillance is important.

Performance Feedback, Internal and External Social Comparisons and Types of Risky Change (WITHDRAWN)

Using a Russell 3000 sample of diversified firms spanning 1998–2016, we extended the behavioral theory of the firm by examining types of risky change through related and unrelated diversification in response to internal and external aspirations among business units within diversified firms. We argued that business units employing sister peers as internal comparison group respond by taking responsibility for performance shortfalls, seeking profitability by facilitating proximal search and advocating for low-risk change through related diversification rather than high-risk change through unrelated diversification. Those benchmarking against market peers, representing external comparison group, attribute performance shortfalls to an organizational problem, prompting distant search and unrelated rather than related diversification. Drawing from contingency theory, we further posited that environmental dynamism is more conducive for related than unrelated diversification in response to performance shortfalls. Our hypotheses were largely supported.

Effect of Periodic Vehicle Inspection on Road Crashes and Injuries: A Systematic Review.

This systematic review was conducted to determine the effect of periodic motor vehicle inspections on road crashes and injuries, compared to less exposure to periodic inspections or no inspections. The Medline, Web of Science, and Scopus databases were used to search the literature. Ecological studies were specifically excluded. A reverse search of the results with these databases and of other identified narrative reviews was also performed. Of the 5065 unique references initially extracted, only six of them met the inclusion criteria and were selected for review: one experimental study, two cohort studies with an internal comparison group, two cohort studies without a comparison group, and one case–control study. Two authors independently extracted the information and assessed the quality of each study. Due to the heterogeneity of the designs and the intervention or comparison groups used, quantitative synthesis of the results was not attempted. Except for the case–control study, which showed a significant association between road crashes and the absence of a valid vehicle inspection certificate, the other studies showed either a small reduction in crash rates (around 9%), no association, or a higher crash rate in vehicles with more inspections. In all observational studies, the risk of residual confounding bias was significant and could have explained the results. Therefore, although the research reviewed here suggests that periodic inspection may be associated with a slight reduction in road crashes, the marked heterogeneity along with probable residual confounding in most reports prevented us from establishing causality for this association.

Improving Debt Literacy by 2/3 Through Four Simple Infographics Requires Numeracy and Not Focusing on Negatives of Debt.

Borrowing behavior may be more resistant to formal educational treatments than other financial behaviors. In order to study the process and results of infographics-based debt education, we used eye tracking technology (SMI RED 500 Hz) to monitor the oculomotor behavior of 108 participants (68 females) aged 18 to 60 who were shown 4 infographics. The study used an experimental design with repeated measures and an internal comparison group. We also used scales of debt literacy and a set of information literacy scales: numerical, graph, and linguistic. The results confirm that short-term infographics-based debt education can improve debt literacy significantly. The difference in processing the educational contents that were not known to participants before the educational session suggests that participants with better information literacy make more considerable debt literacy progress. Specifically, we found that numerical literacy is a significant mediator of debt education results, depending on the initial level of debt literacy; this relation is moderated by the focus of visual attention on negatives of debt. We found no significant relationship between debt literacy education results and those of graph and linguistic literacy.

Incidence and Factors Associated with Death for Tetanus in Adults

Introduction: Tetanus has a worldwide distribution and high lethality. The goal of this study was to characterize the tetanus cases confirmed in Pernambuco and identify factors associated with death in these patients.&#x0D; Methods: Cross-sectional, with internal comparison groups. For data analysis we used the chi-square test and Pearson estimated the odds ratios and their respective confidence intervals at 95%. Multivariate analysis was applied to multiple logistic regression&#x0D; Results: The incidence of tetanus ranged between 0.65 and 2.79 cases per 100,000 inhabitants with higher involvement of adults, male and city population. Only 13.8% had received the vaccine and 23.4% received it as prophylaxis. The average mortality rate was 20.4%. In multivariate analysis, presented neck stiffness as a symptom (p = 0.029), which was associated with increased mortality.&#x0D; Conclusion: There is a need for greater investment in the prevention of the disease, both in immunization coverage and in the application of prophylaxis. Despite the hospitalization guarantee with proper care, there was an increase in tetanus mortality, suggesting that more specific studies should be conducted to investigate what may have influenced this change. Special attention should be offered to cases that presented neck stiffness as a symptom, because these groups have a higher chance of progressing to death.

The Antiretroviral Pregnancy Registry: 30 Years of Monitoring for Congenital Anomalies [OP04-6D

INTRODUCTION: Antiretroviral (ARV) treatment saves lives and prevents vertical transmission of HIV. The Antiretroviral Pregnancy Registry (APR) began prospectively monitoring prenatal ARV use for potential teratogenicity in 1989 and depends on voluntary registration of ARV exposed pregnancies (www.APRegistry.com). METHODS: The APR is an IRB approved, prospective exposure-registration cohort study with data from 70 countries. Prevalence of congenital anomalies (CAs) are estimated and compared to internal and external comparison groups. Twenty-two ARVs have sufficient 1st trimester exposures to detect at least a 2-fold increase in risk of CAs overall, of which 11 can detect a 1.5-fold increase. RESULTS: Of the 20,759 pregnancies prospectively enrolled through 31 July 2019, reported outcomes include 19,642 live births (LB) with ARV exposure at any time during pregnancy and 554 CAs. Prevalence of CAs was 2.8% (95% CI 2.6-3.1) overall, 2.8% (95% CI 2.5-3.1) among 1st trimester exposures and 2.8% (95% CI 2.5-3.2) among 2nd/3rd trimester exposures to ARVs (prevalence ratio 1.00 [95% CI 0.85-1.18]). CONCLUSION: The APR has not detected a significant difference in overall CA prevalence compared to two population based surveillance systems: 2.72/100 LB (95% CI 2.68-2.76) Metropolitan Atlanta Congenital Defects Program (MACDP) and 4.17/100 LB (95% CI 4.15-4.19) Texas Birth Defects Registry (TBDR). Two ARVs, didanosine and nelfinavir, have modest statistically significant increased prevalence compared to MACDP but not TBDR. The APR independent Advisory Committee concludes, “The Registry finds no apparent increases in frequency of specific defects with first trimester exposures and no pattern to suggest a common cause; however, potential limitations of registries should be recognized.”

Patterns of health care utilization of gout patients in Hawai‘i-high rates of emergency department utilization as compared to rheumatoid arthritis

Recent and comprehensive research of gout in the Pacific region and Hawai‘i is significantly lacking. This study was conducted to improve the understanding of the healthcare utilization of gout patients within a single health care system in Hawai‘i. The objective was to examine gout inpatient, outpatient and emergency department care within a single health care system in Hawai‘i. This study was a retrospective chart review of patients, ≥ 18 years admitted to three Hawai‘i Pacific Health facilities for a primary diagnosis of gout or rheumatoid arthritis (RA) from 2011 to 2017. Population data for the State of Hawai‘i was used to calculate visit rates per 1,000 Hawai‘i adults. Trend analysis was performed to compare changes over time. We studied gout health care utilization concurrently with RA to provide an internal comparison group for the healthcare utilization patterns of interest. Gout patients were primarily managed in the outpatient setting with high rates of emergency department visits. In contrast, RA patients were primarily managed in the outpatient setting, with low rates of emergency department visits. Both gout and RA patients had low rates of inpatient admissions. The cost of gout emergency department visits was approximately 3.4 times higher than gout outpatient visits. The rates for gout emergency department visits, outpatient visits, inpatients visits, and RA outpatient visits in 2017 were trending downward and significantly changed from 2011 (p <0.05). The rates for RA emergency department visits and inpatient visits were not significantly changed from 2011–2017. Gout care in Hawai‘i remains suboptimal with higher rates of emergency department visits, as compared to RA. Because emergency department visits are associated with higher cost, efforts should be made to reduce these emergency department visits to improve the quality of care.

The Effectiveness of Fluoroscopically Guided Cervical Transforaminal Epidural Steroid Injection for the Treatment of Radicular Pain; a Systematic Review and Meta-analysis.

Determine the effectiveness of fluoroscopically guided cervical transforaminal epidural steroid injection (CTFESI) for the treatment of radicular pain. Systematic review and meta-analysis. Persons aged ≥18 years with cervical radicular pain due to disc herniation or degenerative spondylosis. Sham, placebo procedure, or active standard of care treatment, excluding alternative versions of epidural steroid injection. The primary outcome measure was patient-reported improvement in pain of at least 50% from baseline, assessed four or more weeks after the treatment intervention. Secondary outcomes included validated functional assessment tools and avoidance of spinal surgery. Randomized or nonrandomized comparative studies and nonrandomized studies without internal control were included. Three reviewers independently assessed publications in the Medline, PubMed, and Cochrane databases up to July 2018. The Grades of Recommendation, Assessment, Development and Evaluation (GRADE) system was used to evaluate risk of bias and overall quality of evidence. A meta-analysis was conducted for comparative measures of effect and for within-group response rates if applicable. There were no studies with an internal comparison group (control group) meeting the review's definition of comparison group. Therefore, comparative measures of effect were not calculated. In cohort studies, pooled response rates were 48% (95% confidence interval [CI] = 34-61%) at one month and 55% (95% CI = 45-64%) at three months. Approximately 50% of patients experience ≥50% pain reduction at short- and intermediate-term follow-up after CTFESI. However, the literature is very low quality according the GRADE criteria, primarily due to a lack of studies with placebo/sham or active standard of care control comparison groups.

Assessing an Interprofessional Polypharmacy and Deprescribing Educational Intervention for Primary Care Post-graduate Trainees: a Quantitative and Qualitative Evaluation.

Polypharmacy and potentially inappropriate medications (PIMs) are increasingly common and associated with adverse health effects. However, post-graduate education in polypharmacy and complex medication management for older adults remain limited. The Initiative to Minimize Pharmaceutical Risk in Older Veterans (IMPROVE) polypharmacy clinic was created to provide a platform for teaching internal medicine (IM) and nurse practitioner (NP) residents about outpatient medication management and deprescribing for older adults. We aimed to assess residents' knowledge of polypharmacy and perceptions of this interprofessional education intervention. A prospective cohort study with an internal comparison group. IM residents and NP residents; Veterans ≥ 65years and taking ≥ 10 medications. IMPROVE consists of a pre-clinic conference, shared medical appointment, individual appointment, and interprofessional precepting model. We assessed residents' performance on a pre-post knowledge test, residents' qualitative assessment of the educational impact of IMPROVE, and the number and type of medications discontinued or decreased. The IMPROVE intervention group (n= 18) had a significantly greater improvement in test scores than the control group (n= 18) (14% ± 15% versus - 1.3% ± 16%) over a period of 6months (Wilcoxon rank sum, p= 0.019). In focus groups, residents (n= 17) reported perceived improvements in knowledge and skills, noting that the experience changed their practice in other clinical settings. In addition, residents valued the unique interprofessional experience. Veterans (n= 71) had a median of 15 medications (IQR 12-19), and a median of 2 medications (IQR 1-3) was discontinued. Vitamins, supplements, and cardiovascular medications were the most commonly discontinued medications, and cardiovascular medications were the most commonly decreased in dose or frequency. Overall, IMPROVE is an effective model of post-graduate primary care training in complex medication management and deprescribing that improves residents' knowledge and skills, and is perceived by residents to influence their practice outside the program.

Correlates of the Women\u2019s Development Army strategy implementation strength with household reproductive, maternal, newborn and child healthcare practices: a cross-sectional study in four regions of Ethiopia

BackgroundTo address the shortfall in human resources for health, Ethiopia launched the Health Extension Program (HEP) in 2004, establishing a health post with two female health extension workers (HEWs) in every kebele (community). In 2011, the Women’s Development Army (WDA) strategy was added, using networks of neighboring women to increase the efficiency of HEWs in reaching every household, with one WDA team leader for every 30 households. Through the strategy, women in the community, in partnership with HEWs, share and learn about health practices and empower one another. This study assessed the association between the WDA strategy implementation strength and household reproductive, maternal, newborn and child health care behaviors and practices.MethodsUsing cross-sectional household surveys and community-level contextual data from 423 kebeles representing 145 rural districts, an internal comparison group design was applied to assess whether HEP outreach activity and household-level care practices were better in kebeles with a higher WDA density. The density of active WDA leaders was considered as WDA strategy implementation strength; higher WDA density in a kebele indicating relatively high implementation strength. Based on this, kebeles were classified as higher, moderate, or lower. Multilevel logit models, adjusted for respondents’ individual, household and contextual characteristics, were used to assess the associations of WDA strategy implementation strength with outcome indicators of interest.ResultsAverage numbers of households per active WDA team leader in the 25th, 50th and 75th percentiles of the kebeles studied were respectively 41, 50 and 73. WDA density was associated with better service for six of 13 indicators considered (p < 0.05). For example, kebeles with one active WDA team leader for up to 40 households (higher category) had respectively 7 (95% CI, 2, 13), 11 (5, 17) and 9 (1, 17) percentage-points higher contraceptive prevalence rate, coverage of four or more antenatal care visits, and coverage of institutional deliveries respectively, compared with kebeles with one active WDA team leader for 60 or more households (lower category).ConclusionHigher WDA strategy implementation strength was associated with better health care behaviors and practices, suggesting that the WDA strategy supported HEWs in improving health care services delivery.

Minimum wages effects on low-skilled workers in less developed regions of China

PurposeThe purpose of this paper is to estimate the causal effect of minimum wages on the employment of low-skilled workers in less developed regions of China.Design/methodology/approachBased on data from the China Health and Nutrition Survey, a double-difference (DD) methodology is used to compare the employment of low-skilled individuals before and after a minimum wage increase in their provinces with a comparison group of individuals in provinces that did not have a minimum wage increase. Also, a triple-difference methodology (DDD) is used that also includes an additional control group of highly educated workers as a within-province internal comparison group that should not be affected by a minimum wage increase.FindingsNo evidence of an adverse employment effect is found in any of the 36 different estimates, consistent with recent US evidence that uses a similar DD methodology.Research limitations/implicationsThe data are not national representative; rather heavily weighted towards the less developed Central, Western and parts of the Eastern Regions of China. This may partially explain the absence of the theoretically expected adverse employment effect. Other related reasons are discussed, including: lack of enforcement in those less developed regions; a large presence of state-owned enterprises in the regions where employment security clause remains intact; the relatively less developed labour markets in the regions including where employers may behave in a monopsony fashion in their labour markets; shock effects; and cost offsets from reduced fringe benefits and increases in the pace of work. This paper was unable to disentangle the separate effect of these possible factors.Originality/valueThis is one of the few studies on minimum wages in China to focus on low-skilled workers in less developed regions, to use individuals as the unit of observation rather than aggregates, and to provide causal estimates based on DD and DDD methodologies.

Addressing Noncommunicable Disease on Short-Term Medical Trips: A Longitudinal Study of Hypertension Treatment in Santo Domingo

BackgroundNoncommunicable diseases (NCDs) are the leading cause of mortality worldwide and pose complex challenges in developing nations. Short-term medical trips, which often operate independently of government and pharmaceutical companies, are in a unique position to address NCDs in developing nations. In 2010, the Dominican Aid Society of Virginia shifted the focus of their semiannual clinic to addressing NCDs in Paraíso, Santo Domingo. ObjectiveThis study analyzes the longitudinal impact of a short-term medical trip on the control of hypertension in their patient population. MethodsReturning patients were identified through a review of medical records from 2014 and 2016. A sample of patients who only visited in either 2014 or 2016 were matched on sex and age and served as an internal comparison group. A generalized linear mixed model was applied to assess changes in blood pressure, the proportion of patients receiving blood pressure treatment, and the intensity of blood pressure treatment within and between returning and new patients over the study period. FindingsThere was a significant decrease in diastolic blood pressure within returning patients. Change in systolic blood pressure was significantly different between returning and new patients, with improvement in returning patients. There was a significant increase in the proportion of new patients receiving blood pressure treatment and a higher intensity of blood pressure treatment over time. The change in the proportion of patients receiving blood pressure treatment in the new patient group was significantly higher than that of the returning patient group. ConclusionsShort-term medical trips with a recurrent presence in a community may improve control of hypertension and other NCDs in developing nations. Further research into the impact that short-term medical trips may have on NCDs is needed.

Animal Embryotoxicity Studies of Key Non-Artemisinin Antimalarials and Use in Women in the First Trimester.

The World Health Organization currently recommends quinine+clindamycin for use against malaria in the first trimester. This may soon change to recommending artemisinin-based combination therapies (standard duration of dosing = 3 days). The non-artemisinin partner drugs include amodiaquine, lumefantrine, mefloquine, piperaquine, sulfadoxine+pyrimethamine, and pyronaridine. For quinine, clindamycin, and mefloquine and the combinations of sulfadoxine+pyrimethamine and artemether+lumefantrine, there are reports (including studies without internal comparison groups) that combined describe 304 to >1100 exposures of women in the first trimester for each drug with no conclusive evidence of adverse effects on pregnancy at therapeutic doses. This is despite the fact that all of these drugs or drug combinations caused embryo deaths and/or malformations in at least one animal species and all except lumefantrine had at least one exposure ratio <1. It now seems that these animal studies overestimated the risk of developmental toxicity in women with malaria. Three other non-artemisinins (amodiaquine, piperaquine, and pyronaridine) have few or no reported exposures in women in the first trimester and have exposure ratios ≤2 based on studies in pregnant rats and rabbits with dosing throughout organogenesis. However, none of these drugs caused embryo deaths or malformations in pregnant rats and rabbits with the exception of pyronaridine, which caused embryo deaths only at a dose that was excessively toxic to the mothers. Thus, for amodiaquine, piperaquine, and pyronaridine, the testing in animals did not reveal findings of concern and the exposure ratios were in the range of the other non-artemisinin antimalarials described above. Birth Defects Research 109:1075-1126, 2017. © 2017 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc.

Long‐term consequences of breastfeeding on cholesterol, obesity, systolic blood pressure and type 2 diabetes: a systematic review and meta‐analysis

To systematically review the evidence on the associations between breastfeeding and overweight/obesity, blood pressure, total cholesterol and type 2 diabetes. Two independent literature searches were carried out using the MEDLINE, LILACS, SCIELO and Web of Science databases. Studies restricted to infants and those without an internal comparison group were excluded. Fixed- and random-effects models were used to pool the estimates. Breastfed subjects were less likely to be considered obese/overweight [pooled odds ratio: 0.74 (95% confidence interval (CI): 0.70; 0.78)] (n = 113). Among the 11 high-quality studies, the association was smaller [pooled odds ratio: 0.87 (95%CI: 0.76; 0.99)]. Total cholesterol (n = 46) was independent of breastfeeding [pooled mean difference: -0.01 mmol/L (95%CI: -0.05; 0.02)]. Systolic blood pressure (n = 43) was lower among breastfed subjects [mean difference: -0.80 (95%CI: -1.17; -0.43)], but no association was observed among larger studies, and for diastolic blood pressure (n = 38) [mean difference: -0.24 (95%CI: -0.50; 0.02)]. For type 2 diabetes (n = 11), the odds ratio was lower among those subjects who had been breastfed [pooled odds ratio: 0.65 (95%CI: 0.49; 0.86)]. Breastfeeding decreased the odds of type 2 diabetes and based on high-quality studies, decreased by 13% the odds of overweight/obesity. No associations were found for total cholesterol or blood pressure.

Vocational Rehabilitation Program Evaluation: Comparison Group Challenges and the Role of Unmeasured Return-to-Work Expectations

Despite the importance and cost of workers' compensation (WC)-based vocational rehabilitation (VR) programs, outcome evaluations are rare, in part due to the scarcity of suitable comparison groups. The aims of this study were to assess (1) the adequacy of a commonly recommended internal comparison group, i.e., workers who were eligible for but did not receive services, and (2) return-to-work (RTW) expectations as a potential source of bias. In this prospective cohort study, we used WC claims data and worker-reported RTW expectations to compare workers who received vocational retraining services to eligible workers who did not receive such services. Workers were surveyed after retraining eligibility determination, prior to the initiation of retraining activities. VR progress and RTW wage outcomes were followed for 3 years. The magnitude of confounding contributed by RTW expectations and other covariates was quantified. Workers who were somewhat or very certain they would RTW had significantly better outcomes. RTW expectations played a strong confounding role, reducing the retraining plan effect estimate by about 23 %, while education and physical capacity each changed the effect estimate by <5 %. RTW expectations predicted long-term RTW outcomes and can play a strong confounding role if unmeasured. We found that the internal comparison group approach, commonly recommended for VR program evaluation, is inappropriate for WC-based VR evaluations. Ultimately, there is no simple solution to the challenge of identifying a comparison group; however, measurement of RTW expectations, an easily-measured multi-dimensional construct, may be a useful addition to the VR evaluation toolbox.

Association of Prescription of Oral Sodium Polystyrene Sulfonate With Sorbitol in an Inpatient Setting With Colonic Necrosis: A Retrospective Cohort Study

Colonic necrosis has been reported after sodium polystyrene sulfonate (SPS)/sorbitol use, but the incidence and relative risk (RR) are not established. Retrospective cohort study. 123,391 adult inpatients at a tertiary medical center. Receipt of SPS prescriptions (exposed) or a prescription other than SPS (unexposed internal comparison group) between September 1, 2001, and October 31, 2010. The main outcome measure was tissue-confirmed diagnosis of colonic necrosis, considered SPS-associated if SPS was prescribed 30 or fewer days before tissue accession date. Demographics, serum chemistry test results, hospital location, and International Classification of Diseases, Ninth Revision diagnostic codes. SPS was prescribed to 2,194 inpatients. 82 inpatient colonic necrosis cases were identified. 3 received oral SPS (1 gram per 4 milliliters of 33% sorbitol) 30 or fewer days before the colonic necrosis accession date (3.7% of inpatient colonic necrosis cases). The data were linked with 123,391 individuals who received inpatient prescriptions between the same dates. Colonic necrosis incidence was 0.14% (95% CI, 0.03%-0.40%) in those prescribed SPS versus 0.07% (95% CI, 0.05-0.08%) in those not prescribed SPS (RR, 2.10; 95% CI, 0.68-6.48; P = 0.2). The number needed to harm was 1,395 (95% CI, 298-5,100). Subgroup analysis (age >65 years; estimated glomerular filtration rate, <30 mL/min/1.73 m(2), intensive care unit admission, or surgical ward status) did not show significant associations. Sample-size analysis indicated that 4,974 SPS-treated individuals older than 65 years and a comparison group 10 times larger would be required for rigorous multivariate analysis of SPS-associated colonic necrosis risk. Individuals with colonic necrosis admitted to non-Department of Defense hospitals would not have been ascertained. Only individuals who had colonic biopsy or surgical tissue submitted for pathologic review could be ascertained as having colonic necrosis. SPS-associated colonic necrosis is rare, and inpatient SPS/sorbitol prescription was not associated significantly with an increased RR of colonic necrosis in this retrospective cohort analysis. Multivariate analysis would require retrospective clinical cohorts from larger or more than one hospital system(s).

Cancer morbidity and quartz exposure in Swedish iron foundries

The aim of this study was to determine cancer morbidity amongst Swedish iron foundry workers with special reference to quartz exposure. In addition to respirable dust and quartz, phenol, formaldehyde, furfuryl alcohols, polycyclic aromatic hydrocarbons (PAHs), carbon black, isocyanates and asbestos are used or generated by foundry production techniques and exposure to any of these substances could have potentially carcinogenic effects. Cancer morbidity between 1958 and 2004 was evaluated in a cohort of 3,045 male foundry workers employed for >1year between 1913 and 2005. Standardised incidence ratios (SIRs) with 95% confidence intervals (95% CI) were determined by comparing observed numbers of incident cancers with frequencies in the Swedish cancer register. Exposure measures were assessed using information from the personal files of employees and modelling quartz measurement based on a database of 1,667 quartz measurements. Dose responses for lung cancer were determined for duration of employment and cumulative quartz exposure for latency periods >20years. Overall cancer morbidity was not increased amongst the foundry workers (SIR 1.00; 95% CI, 0.90-1.11), but the incidence of lung cancer was significantly elevated (SIR 1.61; 95% CI, 1.20-2.12). A non-significant negative dose response was determined using external comparison with a latency period of >20years (SIR 2.05, 1.72 1.26 for the low, medium and high exposure groups), supported by internal comparison data (hazard ratios 1, 1.01, 0.78) for the corresponding groups. For cancers at sites with at least five observed cases and a SIR>1.25, non-significant risks with SIRs>1.5 were determined for cancers of the liver, larynx, testis, connective muscle tissue, multiple myeloma plasmacytoma and lymphatic leukaemia. A significant overall risk of lung cancer was determined, but using external and internal comparison groups could not confirm any dose response at our cumulative quartz dose levels.

HIV Infection, Immunodeficiency, Viral Replication, and the Risk of Cancer

Few studies have compared cancer risk between HIV-infected individuals and a demographically similar HIV-uninfected internal comparison group, adjusting for cancer risk factors. We followed 20,775 HIV-infected and 215,158 HIV-uninfected individuals enrolled in Kaiser Permanente (KP) California for incident cancer from 1996 to 2008. Rate ratios (RR) were obtained from Poisson models comparing HIV-infected (overall and stratified by recent CD4 count and HIV RNA) with HIV-uninfected individuals, adjusted for age, sex, race/ethnicity, calendar period, KP region, smoking, alcohol/drug abuse, and overweight/obesity. We observed elevated RRs for Kaposi sarcoma (KS; RR = 199; P < 0.001), non-Hodgkin lymphoma (NHL; RR = 15; P < 0.001), anal cancer (RR = 55; P < 0.001), Hodgkin lymphoma (HL; RR = 19; P < 0.001), melanoma (RR = 1.8; P = 0.001), and liver cancer (RR = 1.8; P = 0.013), a reduced RR for prostate cancer (RR = 0.8; P = 0.012), and no increased risk for oral cavity/pharynx (RR = 1.4; P = 0.14), lung (RR = 1.2; P = 0.15), or colorectal (RR = 0.9; P = 0.34) cancers. Lung and oral cavity/pharynx cancers were elevated for HIV-infected subjects in models adjusted only for demographics. KS, NHL, anal cancer, HL, and colorectal cancer had significant (P < 0.05) trends for increasing RRs with decreasing recent CD4. The RRs for lung and oral cavity/pharynx cancer were significantly elevated with CD4 < 200 cells/μL and for melanoma and liver cancer with CD4 < 500 cells/μL. Only KS and NHL were associated with HIV RNA. Immunodeficiency was positively associated with all cancers examined except prostate cancer among HIV-infected compared with HIV-uninfected individuals, after adjustment for several cancer risk factors. Earlier antiretroviral therapy initiation to maintain high CD4 levels might reduce the burden of cancer in this population.