Experimental Analysis of Neighborhood Effects

Families, primarily female-headed minority households with children, living in high-poverty public housing projects in five U.S. cities were offered housing vouchers by lottery in the Moving to Opportunity program. Four to seven years after random assignment, families offered vouchers lived in safer neighborhoods that had lower poverty rates than those of the control group not offered vouchers. We find no significant overall effects of this intervention on adult economic self-sufficiency or physical health. Mental health benefits of the voucher offers for adults and for female youth were substantial. Beneficial effects for female youth on education, risky behavior, and physical health were offset by adverse effects for male youth. For outcomes exhibiting significant treatment effects, we find, using variation in treatment intensity across voucher types and cities, that the relationship between neighborhood poverty rate and outcomes is approximately linear.

Moving to Opportunity in Boston: Early Results of a Randomized Mobility Experiment

This paper examines the short-run impacts of a change in residential neighborhood on the well-being of low-income families, using evidence from the Moving To Opportunity (MTO) program in which eligibility for a housing voucher was determined by random lottery. Applicants in high poverty public housing projects were assigned by lottery to one of three groups: Experimental offered mobility counseling and a voucher valid only in a low-poverty Census tract; Section 8 Comparison offered a geographically unrestricted voucher; or Control offered no new assistance, but continued eligibility for public housing. Our quantitative analyses of program impacts at the Boston site of MTO uses data on 540 families approximately two years after program enrollment. 48 percent of the Experimental group and 62 percent of the Section 8 Comparison group moved through the MTO program. Households in both treatment groups experienced improvements in multiple measures of well-being relative to the Control group including increased safety, improved health among household heads, and fewer behavior problems among boys. There were no significant short-run impacts of either MTO treatment on employment, earnings, or welfare receipt. Experimental group children were less likely to be personally victimized by crime, to be injured, or to experience an asthma attack.

Moving to Opportunity and Tranquility: Neighborhood Effects on Adult Economic Self-Sufficiency and Health From a Randomized Housing Voucher Experiment

neighborhood effects, housing vouchers

What Can We Learn about Neighborhood Effects from the Moving to Opportunity Experiment?

Experimental estimates from Moving to Opportunity (MTO) show no significant impacts of moves to lower‐poverty neighborhoods on adult economic self‐sufficiency four to seven years after random assignment. The authors disagree with Clampet‐Lundquist and Massey's claim that MTO was a weak intervention and therefore uninformative about neighborhood effects. MTO produced large changes in neighborhood environments that improved adult mental health and many outcomes for young females. Clampet‐Lundquist and Massey's claim that MTO experimental estimates are plagued by selection bias is erroneous. Their new nonexperimental estimates are uninformative because they add back the selection problems that MTO's experimental design was intended to overcome.Economic

Prevalence and risk factors for periprosthetic fracture in older recipients of total hip replacement: a cohort study

Background: The growing utilization of total joint replacement will increase the frequency of its complications, including periprosthetic fracture. The prevalence and risk factors of periprosthetic fracture require further study, particularly over the course of long-term follow-up. The objective of this study was to estimate the prevalence and risk factors for periprosthetic fractures occurring in recipients of total hip replacement. Methods: We identified Medicare beneficiaries who had elective primary total hip replacement (THR) for non-fracture diagnoses between July 1995 and June 1996. We followed them using Medicare Part A claims data through 2008. We used ICD-9 codes to identify periprosthetic femoral fractures occurring from 2006–2008. We used the incidence density method to calculate the annual incidence of these fractures and Cox proportional hazards models to identify risk factors for periprosthetic fracture. We also calculated the risk of hospitalization over the subsequent year. Results: Of 58,521 Medicare beneficiaries who had elective primary THR between July 1995 and June 1996, 32,463 (55%) survived until January 2006. Of these, 215 (0.7%) developed a periprosthetic femoral fracture between 2006 and 2008. The annual incidence of periprosthetic fracture among these individuals was 26 per 10,000 person-years. In the Cox model, a greater risk of periprosthetic fracture was associated with having had a total knee replacement (HR 1.82, 95% CI 1.30, 2.55) or a revision total hip replacement (HR1.40, 95% CI 0.95, 2.07) between the primary THR and 2006. Compared to those without fractures, THR recipients who sustained periprosthetic femoral fracture had three-fold higher risk of hospitalization in the subsequent year (89% vs. 27%, p < 0.0001). Conclusion: A decade after primary THR, periprosthetic fractures occur annually in 26 per 10,000 persons and are especially frequent in those with prior total knee or revision total hip replacements

Epidemiology of musculoskeletal upper extremity ambulatory surgery in the United States

Background: Musculoskeletal disorders of the upper extremity are common reasons for patients to seek care and undergo ambulatory surgery. The objective of our study was to assess the overall and age-adjusted utilization rates of rotator cuff repair, shoulder arthroscopy performed for indications other than rotator cuff repair, carpal tunnel release, and wrist arthroscopy performed for indications other than carpal tunnel release in the United States. We also compared demographics, indications, and operating room time for these procedures. Methods: We used the 2006 National Survey of Ambulatory Surgery to estimate the number of procedures of interest performed in the United States in 2006. We combined these data with population size estimates from the 2006 U.S. Census Bureau to calculate rates per 10,000 persons. Results: An estimated 272,148 (95% confidence intervals (CI) = 218,994, 325,302) rotator cuff repairs, 257,541 (95% CI = 185,268, 329,814) shoulder arthroscopies excluding those for cuff repairs, 576,924 (95% CI = 459,239, 694,609) carpal tunnel releases, and 25,250 (95% CI = 17,304, 33,196) wrist arthroscopies excluding those for carpal tunnel release were performed. Overall, carpal tunnel release had the highest utilization rate (37.3 per 10,000 persons in persons of age 45–64 years; 38.7 per 10,000 persons in 65–74 year olds, and; 44.2 per 10,000 persons in the age-group 75 years and older). Among those undergoing rotator cuff repairs, those in the age-group 65–74 had the highest utilization (28.3 per 10,000 persons). The most common indications for non-cuff repair related shoulder arthroscopy were impingement syndrome, periarthritis, bursitis, and instability/SLAP tears. Non-carpal tunnel release related wrist arthroscopy was most commonly performed for ligament sprains and diagnostic arthroscopies for pain and articular cartilage disorders. Conclusions: Our data shows substantial age and demographic differences in the utilization of these commonly performed upper extremity ambulatory procedures. While over one million upper extremity procedures of interest were performed, evidence-based clinical indications for these procedures remain poorly defined

Metal Enrichment of the Intergalactic Medium in Cosmological Simulations

Observations have established that the diffuse intergalactic medium (IGM) at z ~ 3 is enriched to ~0.1-1% solar metallicity and that the hot gas in large clusters of galaxies (ICM) is enriched to 1/3-1/2 solar metallicity at z=0. Metals in the IGM may have been removed from galaxies (in which they presumably form) during dynamical encounters between galaxies, by ram-pressure stripping, by supernova-driven winds, or as radiation-pressure driven dust efflux. This study develops a method of investigating the chemical enrichment of the IGM and of galaxies, using already completed cosmological simulations. To these simulations, we add dust and (gaseous) metals, distributing the dust and metals in the gas according to three simple parameterized prescriptions, one for each enrichment mechanism. These prescriptions are formulated to capture the basic ejection physics, and calibrated when possible with empirical data. Our results indicate that dynamical removal of metals from >~ 3*10^8 solar mass galaxies cannot account for the observed metallicity of low-column density Ly-alpha absorbers, and that dynamical removal from >~ 3*10^10 solar mass galaxies cannot account for the ICM metallicities. Dynamical removal also fails to produce a strong enough mass-metallicity relation in galaxies. In contrast, either wind or radiation-pressure ejection of metals from relatively large galaxies can plausibly account for all three sets of observations (though it is unclear whether metals can be distributed uniformly enough in the low-density regions without overly disturbing the IGM, and whether clusters can be enriched quite as much as observed). We investigate in detail how our results change with variations in our assumed parameters, and how results for the different ejection processes compare. (Abridged)Comment: Minor revision, 1 figure added addressing diffusion of metals after their ejection. Accepted by ApJ. 31 EmulateApj Pages with 13 embedded postscript figure

Yield of clinical and radiographic surveillance in patients with resected pancreatic adenocarcinoma following multimodal therapy

AbstractBackgroundFollowing potentially curative resection at this centre, patients with pancreatic adenocarcinoma (PAC) are routinely enrolled in a programme of clinical and radiographic surveillance. This study sought to evaluate its diagnostic yield.MethodsAll patients who underwent pancreaticoduodenectomy for PAC at this institution during 1998–2008 were identified. Patients with asymptomatic recurrence were compared with those with symptomatic recurrence. Factors associated with survival following the detection of recurrence were compared.ResultsA total of 216 of 327 (66.1%) resected patients developed recurrence. Asymptomatic recurrence was detected in 118 (54.6%) patients. Symptomatic recurrence was associated with multifocal disease or carcinomatosis, poor performance status and less frequent subsequent therapy. Median time to recurrence did not differ between groups, but survival after detection was shorter in symptomatic patients (5.1months vs. 13.0months; P < 0.001). Treatment was administered more frequently to asymptomatic patients (91.2% vs. 61.4%; P < 0.001). At recurrence, a preserved performance status score of ≤1, further therapy, low CA 19-9, and an isolated site of recurrence were independently associated with longer post-recurrence survival (P < 0.001).ConclusionsOverall, 54.6% of cases of recurrent PAC were detected prior to the onset of symptoms using a standardized clinical and radiographic surveillance strategy. Although this retrospective analysis limits definitive conclusions associating this strategy with survival, these results suggest the need for further studies of postoperative surveillance

Outcomes of Ultrasound-guided Glen Humeral Corticosteroid Injections in Adhesive Capsulitis

Aims To assess short and longer-term outcomes of ultrasound-guided glenohumeral corticosteroid injections for adhesive capsulitis. Study Design A mixed prospective and retrospective study design Place and Duration of Study Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Department of Orthopaedic Surgery, Brigham and Women’s Hospital, between June 2011 and July 2012. Methodology Using medical records, we first retrospectively identified patients who had received ultrasound-guided injections of lidocaine and triamcinolone for adhesive capsulitis We then assessed short-term follow-up outcomes (within 3 months of procedure) using medical record review and phone interviews. Longer-term follow-up (at least 3 months from the procedure) outcomes were determined by mailings and phone calls. Average and worst shoulder pain scores were measured on a visual analog scale. Shoulder ROM was measured in forward flexion, isolated abduction, and external rotation. Results: Patients presented an average of 5.1 (SD=4.1) months after onset of symptoms. Within three months of the injection, 55.9% (95% CI: 39.2%, 72.6%) of patients reported greater than 75% pain relief and 44.1% (95% CI: 27.4%, 60.8%) of patients reported greater than 75% ROM improvement. The percentage of patients who improved increased with increased duration of follow-up. At short-term follow-up (mean=2.1 months, SD=2.7), average pain decreased from 5.6 (SD=2.2) to 3.0 (SD=1.8) (p ≤ .001) and worst pain decreased from 7.8 (SD=1.2) to 4.3 (SD=3.2) (p ≤ .001). At longer-term follow-up (mean =10.4 months, SD=3.7), average pain decreased to 1.9 (SD=1.9) (p ≤ .001) and worst pain decreased to 2.9 (SD=2.3) (p ≤ .001). Conclusion: A majority of patients had significant pain reduction and functional improvement after an ultrasound guided glenohumeral corticosteroid injection for adhesive capsulitis. Our patients experience the majority of their pain and functional relief within the first three months after an ultrasound-guided corticosteroid injection with continued increase in relief in the longer-term