Odds Of Closure Research Articles

Trends in Dialysis Industry Consolidation After Medicare Payment Reform, 2006-2016

The dialysis industry is highly concentrated, with large dialysis organizations now providing dialysis for more than 85% of patients with kidney failure in the United States. In 2011, Medicare introduced a new Prospective Payment System (PPS) for end-stage kidney disease, which bundled payment for dialysis care into 1 payment per patient. Trends in dialysis facility consolidation after the PPS went into effect are unknown. To determine whether the introduction of the PPS in 2011 was associated with an acceleration in acquisitions and closures of small dialysis chains (<20 facilities) and independently owned facilities. This retrospective cohort study included all Medicare-certified independent or small chain-affiliated dialysis facilities in the continental US between 2006 and 2016. Data were obtained from Medicare and the US Renal Data System and were analyzed in 2020. The PPS. Discrete time hazard models were used to estimate the odds of acquisition and closure before the PPS (2006-2010) vs after the PPS (2011-2016). Analyses controlled for facility, market, and regional demographic characteristics. The average predicted marginal probabilities of acquisition and closure over time were estimated. The proportion of small chain-affiliated and independently owned facilities declined from 29% (1383 of 4750 facilities) in 2006 to 15% (1038 of 6738) in 2016. Among 13 481 facility-years, 6352 (47%) were for profit, and mean (SD) census was 68 (59) patients. Overall, 3286 (24%) facilities opened during the observation period. The proportion of acquisitions that occurred each year varied from 1.1% (12 of 1065 facilities in 2015) to 7.2% (86 of 1192 facilities in 2012), while closures varied from 0.8% (9 of 1065 facilities in 2015) to 2.2% (28 of 1286 facilities in 2010), making both fairly rare. There was a 3.48 higher odds of acquisition in the post-PPS period compared with the pre-PPS period (95% CI, 1.62-7.47; P = .001). The odds of closure before and after the PPS were not statistically significantly different (odds ratio, 2.03; 95% CI, 0.61-6.73; P = .25). Facilities that opened during the observation period had a 7.2% higher predicted probability of acquisition compared with older facilities (95% CI, 5.4%-9.0%; P < .001). In this cohort study of continental US Medicare-certified dialysis facilities, small-chain and independently owned facilities retained a declining share of the dialysis market. Further research should evaluate the effect of continued dialysis market consolidation on patient access, health care utilization, and clinical outcomes.

OUTCOME OF REVISION PROCEDURES FOR FAILED PRIMARY MACULAR HOLE SURGERY.

To analyze the outcomes of revision surgery for idiopathic full-thickness macular holes that have failed to close after primary surgery, and also to assess factors predicting success and to review the relative effect of adjunctive surgical techniques. A multicenter retrospective study. Anatomical closure rates and visual acuity change between pre and postrevision surgery were assessed. Hole size, age, symptom duration, surgical interval, and reduced hole size were analyzed as predictive factors for success. Effectiveness of adjunctive surgical techniques was reviewed. Seventy-seven eyes were included in the study. Anatomical closure was achieved in 71% (55/77) cases. There was a median gain of 11 Early Treatment of Diabetic Retinopathy Score letters in all holes and 14 letters in closed holes. Full-thickness macular holes that increased in size by more than 10% following primary surgery had a closure rate of 50% compared with 80% in holes that reduced by 10% or stayed the same (P = 0.015). Increasing hole size is associated with a modest reduction in odds of closure (odds ratio = 0.99; P = 0.04). Surgical interval <2 months is not associated with better outcomes compared with >2 months (P = 0.14). Revision surgery for full-thickness macular holes that have failed to close after primary surgery is associated with high closure rates and significant visual gains.

Revisiting the Risks of Bitcoin Currency Exchange Closure

Bitcoin has enjoyed wider adoption than any previous cryptocurrency; yet its success has also attracted the attention of fraudsters who have taken advantage of operational insecurity and transaction irreversibility. We study the risk that investors face from the closure of Bitcoin exchanges, which convert between Bitcoins and hard currency. We examine the track record of 80 Bitcoin exchanges established between 2010 and 2015. We find that nearly half (38) have since closed, with customer account balances sometimes wiped out. Fraudsters are sometimes to blame, but not always. Twenty-five exchanges suffered security breaches, 15 of which subsequently closed. We present logistic regressions using longitudinal data on Bitcoin exchanges aggregated quarterly. We find that experiencing a breach is correlated with a 13 times greater odds that an exchange will close in that same quarter. We find that higher-volume exchanges are less likely to close (each doubling in trade volume corresponds to a 12% decrease in the odds of closure). We also find that exchanges that derive most of their business from trading less popular (fiat) currencies, which are offered by at most one competitor, are less likely to close.