Association of Race, Health Insurance Status, and Household Income With Location and Outcomes of Ambulatory Surgery Among Adult Patients in 2 US States.

Importance: The receipt of surgery in freestanding ambulatory surgery centers (ASCs) is often less costly compared with surgery in hospital-based outpatient departments. Although increasing numbers of surgical procedures are now being performed in freestanding ASCs, questions remain regarding the existence of disparities among patients receiving care at ASCs. Objective: To examine the association of patient race, health insurance status, and household income with the location (ASC vs hospital-based outpatient department) of ambulatory surgery. Design, Setting, and Participants: This cohort study used data from the State Ambulatory Surgery and Services Databases of the Healthcare Cost and Utilization Project to perform a secondary analysis of patients who received ambulatory surgery in New York and Florida between 2011 and 2013. Patients aged 18 to 89 years who underwent 12 different types of ambulatory surgical procedures were included. Data were analyzed from December 2018 to June 2019. Main Outcomes and Measures: Receipt of surgery at a freestanding ASC and 30-day unplanned hospital visits after ambulatory surgery. Results: A total of 5.6 million patients in New York (57.4% female; 68.9% aged ≥50 years; and 62.5% White) and 7.5 million patients in Florida (57.3% female; 77.4% aged ≥50 years; 74.3% White) who received ambulatory surgery were included in the analysis. After adjusting for age, comorbidities, health insurance status, household income, location of surgery, and type of surgical procedure, the likelihood of receiving ambulatory surgery at a freestanding ASC was significantly lower among Black patients (adjusted odds ratio [aOR], 0.82; 95% CI, 0.81-0.83; P < .001) and Hispanic patients (aOR, 0.78; 95% CI, 0.77-0.79; P < .001) compared with White patients in New York. This likelihood was also lower among Black patients (aOR, 0.65; 95% CI, 0.65-0.66; P < .001) compared with White patients in Florida. Public health insurance coverage was associated with a significantly lower likelihood of receiving ambulatory surgery at freestanding ASCs in both New York and Florida, particularly among patients with Medicaid (in New York, aOR, 0.22; 95% CI, 0.22-0.22; P < .001; in Florida, aOR, 0.40; 95% CI, 0.40-0.41; P < .001) and Medicare (in New York, aOR, 0.46; 95% CI, 0.46-0.46; P < .001; in Florida, aOR, 0.67; 95% CI, 0.66-0.67; P < .001). Conclusions and Relevance: Differences in the use of freestanding ASCs were found among Black patients and patients with public health insurance. Further exploration of the factors underlying these differences will be important to ensure that all populations have access to the increasing number of freestanding ASCs.

Healthcare costs for abortions performed in ambulatory surgery centers vs office-based settings.

BACKGROUND: Several states require that abortions be provided in ambulatory surgery centers. Supporters of such laws argue that they make abortions safer, yet previous studies have found no differences in abortion-related morbidities or adverse events for abortions performed in ambulatory surgery centers versus office-based settings. However, little is known about how costs of abortions provided in ambulatory surgery centers differ from those provided in office-based settings. OBJECTIVE: To compare healthcare expenditures for abortions performed in ambulatory surgery centers versus office-based settings using a large national private insurance claims database. MATERIALS AND METHODS: A retrospective cohort study compared expenditures for abortions performed in ambulatory surgery centers versus office-based settings. Data on women who had abortions in an ambulatory surgery center or office-based setting between January 1, 2011, and December 31, 2014 were obtained from the MarketScan Commercial Claims and Encounters database. The sample was limited to women who were continuously enrolled in their insurance plans for at least 1 year before and at least 6 weeks after the abortion. Healthcare expenditures were assessed separately for the index abortion and the 6-week period after the abortion. Costs were measured from the perspective of the healthcare system and included all payments to the provider, including insurance company payments and any patient out-of-pocket payments. RESULTS: Overall, 49,287 beneficiaries who had 50,311 abortions met inclusion criteria. Of the included abortions, 47% were first-trimester aspiration, 27% first-trimester medication, and 26% second-trimester or later abortions. Most abortions (89%) were provided in office-based settings, with 11% provided in ambulatory surgery centers. Unadjusted mean index abortion costs were higher in ambulatory surgery centers than in office-based settings ($1704 versus $810; P < .001). After adjusting for patient clinical and demographic characteristics, costs of index abortions were $772 higher (95% confidence interval, $746-$797), total follow-up costs for abortions that had any follow-up care were $1099 higher (95% confidence interval, $1004-$1,195), and total follow-up costs for abortions that had an abortion-related morbidity or adverse event were not significantly different in ambulatory surgery centers compared to office-based settings. There were also no significant differences in the likelihood of having any follow-up care or abortion-related event follow-up care. CONCLUSION: Abortions performed at ambulatory surgery centers are significantly more costly than those performed in office-based settings, with no difference in the likelihood of receiving follow-up care. Laws requiring that abortions be provided in ambulatory surgery centers may only result in increased costs for abortions, with no effect on abortion safety.

Same-Day vs Different-Day Elective Upper and Lower Endoscopic Procedures by Setting.

Importance: Performing elective upper and lower endoscopic procedures on the same day is a patient-centered and less costly approach than a 2-stage approach performed on different days, when clinically appropriate. Whether this practice pattern varies based on practice setting has not been studied. Objectives: To estimate the rate of different-day upper and lower endoscopic procedures in 3 types of outpatient settings and investigate the factors associated with the performance of these procedures on different days. Design, Setting, and Participants: A retrospective analysis was conducted of Medicare claims between January 1, 2011, and June 30, 2018, for Medicare beneficiaries who underwent a pair of upper and lower endoscopic procedures performed within 90 days of each other at hospital outpatient departments (HOPDs), freestanding ambulatory surgery centers (ASCs), and physician offices. Main Outcomes and Measures: Undergoing an upper and a lower endoscopic procedure on different days, adjusted for patient characteristics (age, sex, race/ethnicity, residence location and region, comorbidity, and procedure indication) and physician characteristics (sex, years in practice, procedure volume, and primary specialty). Adjusted odds ratios (aORs) and 95% CIs were calculated. Results: A total of 4 028 587 procedure pairs were identified, of which 52.5% were performed in HOPDs, 43.3% in ASCs, and 4.2% in physician offices. The rate of different-day procedures was 13.6% in HOPDs, 22.2% in ASCs, and 47.7% in physician offices. For the 7564 physicians who practiced at both HOPDs and ASCs, their different-day procedure rate changed from 14.1% at HOPDs to 19.4% at ASCs. For the 993 physicians who practiced at both HOPDs and physician offices, their different-day procedure rate changed from 15.8% at HOPDs to 37.4% at physician offices. Patients were more likely to undergo different-day procedures at physician offices and ASCs compared with HOPDs, even after adjusting for patient and physician characteristics (physician office vs HOPD: aOR, 2.02; 95% CI, 1.85-2.20; ASC vs HOPD: aOR, 1.27; 95% CI, 1.23-1.32). Older age (85-94 years vs 65-74 years: aOR, 1.10; 95% CI, 1.08-1.11; 95 years or older vs 65-74 years: aOR, 1.14; 95% CI, 1.03-1.26), black and Hispanic race/ethnicity (black: aOR, 1.15; 95% CI, 1.12-1.17; Hispanic: aOR, 1.12; 95% CI, 1.10-1.14), and residing in the Northeast region (adjusted OR, 1.32; 95% CI, 1.28-1.36) were risk factors for undergoing different-day procedures. Micropolitan location (aOR, 0.94; 95% CI, 0.92-0.96) and rural location (aOR, 0.91; 95% CI, 0.89-0.93), more comorbidities (≥5: aOR, 0.75; 95% CI, 0.74-0.76), physician's fewer years in practice (aOR, 0.84; 95% CI, 0.81-0.87), physician's higher procedure volume (aOR, 0.65; 95% CI, 0.62-0.68), and physician's specialty of general surgery (aOR, 0.86; 95% CI, 0.80-0.91) were protective factors. Conclusions and Relevance: Physician offices and ASCs had much higher different-day procedure rates compared with HOPDs. This disparity may represent an opportunity for quality improvement and financial savings for common endoscopic procedures.

Understanding the surgical care needs and use of outpatient surgical care services among homeless patients at the Ottawa Hospital

Background: The use of outpatient health care services by homeless people is low compared to their high level of need; however, it is unclear whether this applies to surgical care. We sought to describe surgical care access among homeless patients in a Canadian tertiary care setting. Methods: We reviewed the medical records of adult (age > 18 yr) patients with no fixed address or a shelter address who presented to The Ottawa Hospital Emergency Department from Jan. 1, 2013, to Dec. 31, 2014, and required surgical referral. We analyzed the data using descriptive statistics. Results: A surgical referral was initiated in 129 emergency department visits for 97 patients (77 men [79%], mean age 46.7 yr). Most patients lived in shelters (77 [79%]) and had provincial health insurance (82 [84%]), but only 35 (36%) had a primary care physician. The mean number visits for any reason was 7.9 (standard deviation 13.7) (range 1­106). The majority of surgical referrals (83 [64.3%]) were for traumatic injuries, and the most frequently consulted service (52 [40.3%]) was orthopedic surgery. Just under half (48 [49%]) of referred patients attended at least 1 outpatient appointment, and only a third (33 [34%]) completed full follow-up. Conclusion: Homeless patients presenting to an emergency department and requiring surgical care were predominantly men living in shelters, most frequently seeking care for traumatic injuries. Current outpatient services may not meet the surgical care needs of these patients, as many do not access them. Alternative approaches to outpatient care must be considered, particularly among high-need services such as orthopedics, to support surgical care access among this population.

Contexte: L'utilisation des services de santé ambulatoires par les sans-abri est faible si on la compare à leurs besoins qui sont élevés; on ignore par contre s'il en va de même pour les soins chirurgicaux. Nous avons voulu décrire l'accès aux soins chirurgicaux chez les patients sans domicile fixe dans un hôpital de soins tertiaires au Canada. Méthodes: Nous avons passé en revue les dossiers médicaux de patients adultes (âge > 18 ans) sans domicile fixe ayant consulté aux urgences de l'Hôpital d'Ottawa entre le 1er janvier 2013 et le 31 décembre 2014, et pour qui une consultation en chirurgie avait été demandée. Nous avons analysé les données au moyen de statistiques descriptives. Résultats: Une consultation en chirurgie a été demandée lors de 129 visites aux urgences, pour 97 patients (77 hommes [79 %], âge moyen 46,7 ans). La plupart de ces patients vivaient dans des refuges (77 [79 %]) et bénéficiaient d'un régime d'assurance maladie provincial (82 [84 %]), mais seulement 35 (36 %) avaient un médecin de famille. Le nombre moyen de visites, toutes raisons confondues, a été de 7,9 (écart-type 13,7) (entre 1 et 106). La majorité des demandes de consultations en chirurgie (83 [64,3 %]) concernaient des lésions traumatiques et le service le plus souvent appelé en consultation (52 [40,3 %]) était la chirurgie orthopédique. Un peu moins de la moitié (48 [49 %]) des patients envoyés en consultation se sont présentés à au moins un rendez-vous en clinique externe, et seulement le tiers d'entre eux (33 [34 %]) se sont soumis au suivi complet. Conclusion: Les patients sans domicile fixe qui consultent aux urgences et ont besoin de soins chirurgicaux étaient principalement des hommes hébergés dans des refuges ayant le plus souvent consulté pour des blessures traumatiques. Les services ambulatoires actuels ne répondent peut-être pas aux besoins chirurgicaux de ces patients, car plusieurs n'y accèdent pas. Il faudrait envisager d'autres approches, particulièrement en ce qui concerne les services très en demande, comme l'orthopédie, pour faciliter l'accès aux soins chez cette population.

The Impact of Price Transparency for Surgical Services.

Increasing insurance deductibles have prompted some medical centers to initiate transparent pricing. However, the impact of price transparency (PT) on surgical volume, revenue, and patient satisfaction is unknown, along with the barriers to achieving PT. We identified ambulatory surgical centers in the Free Market Medical Association database that publicly list prices for surgical services online. Six of eight centers (75%) responded to our data collection inquiry. Among five centers that reported their patient volume and revenue after adopting PT, patient volume increased by a median of 50 per cent (range 10-200%) at one year. Four centers (80%) reported an increase in revenue by a median of 30 per cent (range 4-75%), whereas three centers (60%) experienced an increase in third-party administrator contracts with the average increase being seven new third-party administrator contracts (range = 2-12 contracts). Three centers (50%) reported a reduction in their administrative burden and five centers (83%) reported an increase in patient satisfaction and patient engagement after PT. The leading barrier reported to making prices transparent was discouragement from another practice, hospital, or insurance company. The findings of this preliminary study may help guide medical practices in designing and implementing PT strategies.

Association between outpatient orthopedic surgery costs and healthcare facility characteristics.

Purpose The purpose of this paper is to examine the association between outpatient orthopedic surgery costs and Japan's healthcare facilities using a large-scale Japanese medical claims database. Design/methodology/approach The authors obtained reimbursement claims data for 8,588 patients who underwent orthopedic surgery between April 1 and September 30, 2014 at 3,347 Japanese healthcare facilities. Regression analysis, using ordinary least squares, examined the association between outpatient orthopedic surgery costs and healthcare facility characteristics. By using surgical fees as proxy for the surgical costs, the authors defined three dependent variables: surgical cost for each outpatient orthopedic surgery; pre- and post-operative cost one month before and after a surgical operation; and total cost for each patient. The authors also defined five independent variables, which capture healthcare facility characteristics and patient-specific factors: bed count; whether healthcare facilities are reimbursed in a diagnosis procedure combination system; patient's age; sex; and anatomical surgical sites. Findings The authors analyzed 6,456 outpatient orthopedic surgical cases performed at 3,085 healthcare facilities. There were significant differences in the surgical costs for outpatient orthopedic surgery among different healthcare facilities by total beds ( p=0.000). Multivariate regression analysis shows that surgical costs for outpatient orthopedic surgery are positively and significantly associated with healthcare facilities classified by total beds after adjusting for patient-specific characteristics ( p<0.05). Originality/value This is the first research to examine the association between costs for outpatient orthopedic surgery and healthcare facility characteristics in Japan. This study via the multivariate regression method showed that outpatient orthopedic surgery is likely to cost higher as healthcare facility size increased. The average incremental costs for each outpatient orthopedic surgery per 100 beds were calculated at $48.5 for surgery, $40.7 for pre- and post-operative care, and $89.2 total cost.

Physician Reimbursement for Prostate Biopsies Falls as Procedures Shift From Offices to Facilities.

OBJECTIVE: To examine how Medicare reimbursement for prostate biopsies was allocated to physicians, ambulatory surgery centers (ASCs), and hospitals from 2012 to 2015. MATERIALS AND METHODS: Using Medicare Provider Utilization and Payment Data (2012-2015), we assessed provider payments to physicians and ASCs for transrectal ultrasound-guided prostate biopsies (Current Procedural Terminology 55700, 76842, 76972) for fee-for-service Medicare beneficiaries. Data were aggregated at provider-level for those reporting >10 biopsies per year. Hospital payments were estimated based on Outpatient Prospective Payment System. We report average and total payments for physicians, hospitals, and ASCs. RESULTS: We identified 534,807 prostate biopsies, of which 13.3% and 14.8% were associated with an ASC and hospital, respectively. Payments for all biopsies totaled $276.7 million ($152.7 million to physicians; $35.1 million to ASCs, $88.9 million to hospitals). From 2012 through 2015, physician payments for biopsies declined by $19 million (Δ=-43.2%, P = .06 for trend). Payments to ASCs (+$3.2 million, Δ = 38.8%, P = .29) and hospitals (+$11.1 million, Δ = 58.6%, P = .16) both increased. The decline in physician payments was due to a 13.7% decline in volume and lower median reimbursement for office-based procedures ($415 to $277, P = .04). The share of biopsies performed at facilities increased from 26.5% to 30.0%, and the proportion of payments associated with those settings also increased from 42.7% to 65.3%. CONCLUSION: Over time, a greater share of Medicare payments for biopsies has been directed toward facilities instead of physicians. Understanding the relationship between these trends and cancer screening and Medicare payment policies will be crucial in the future.

The British Association of Urological Surgeons (BAUS) radical prostatectomy audit 2014/2015 - an update on current practice and outcomes by centre and surgeon case-volume.

OBJECTIVES: To describe contemporary radical prostatectomy (RP) practice using the British Association of Urological Surgeons (BAUS) data and audit project and to observe differences in practice in relation to surgeon or centre case-volume. PATIENTS AND METHODS: Data on 13 920 RP procedures performed by 179 surgeons across 86 centres were recorded on the BAUS data and audit platform between 1 January 2014 and 31 December 2015. This equates to ~95% of total RPs performed over this period when compared to Hospital Episode Statistics (HES) data. Centre case-volumes were categorised as 'high' (>200), 'medium' (100-200) and 'low' (<100); surgeon case-volumes were categorised as 'high' (>100) and 'low' (<100). Differences in surgical practice and selected outcome measures were observed between groups. All data and volume categories were for the combined 2-year period. RESULTS: The median number of RPs performed over the 2-year period was 63.5 per surgeon and 164 per centre. Overall, surgical approach was robot-assisted laparoscopic RP (RALP) in 65%, laparoscopic RP (LRP) in 23%, and open RP (ORP) in 12%. The dominant approach in high-case-volume centres and by high-case-volume surgeons was RALP (74.3% and 69.2%, respectively). There was a greater percentage of ORPs reported by low-volume surgeons and centres when compared to higher volume equivalents. In all, 51.6% of all patients in this series underwent RP in high-case-volume centres using robot-assisted surgery (RAS). High-case-volume surgeons performed nerve-sparing (NS) procedures on 57.3% of their cases; low-volume surgeons performing NS on 48.2%. Overall, lymph node dissection (LND) rates were very similar across the groups. An 'extended' LND was more commonly performed in high-volume centres (22.1%). The median length of stay (LOS) was lowest in patients undergoing RALP at high-volume centres (1 day) and highest in ORP across all volume categories (3-4 days). Reported pT2 positive surgical margin (PSM) rate varied by technique, centre volume, and surgeon volume. In general, observed PSM rates were lower when RALP was the surgical approach (14.4%) and when high-volume surgeons were compared to low-volume surgeons (13.6% vs 17.7%). Transfusion rates were highest in ORP across all centres and surgeons (2.96-4.49%) compared to techniques using a minimally-invasive approach (0.25-2.41%). Training cases ranged from 0.5% in low-volume centres to 6.0% in high-volume centres. CONCLUSIONS: Compliance with data registration for centres and surgeons performing RP is high in the present series. Most RPs were performed in high-case-volume centres and by high-case-volume surgeons, with the most common approaches being minimally invasive and specifically RAS. High-case-volume centres and surgeons reported higher rates of extended LND and training cases. Higher-case-volume surgeons reported lower pT2 PSM rates, whilst the most marked differences in transfusion rates and LOS were seen when ORP was compared to minimally invasive approaches. Caution must be applied when interpreting these differences on the basis of this being registry data - causality cannot be assumed.

Cost Savings From Utilization of an Ambulatory Surgery Center for Orthopaedic Day Surgery.

INTRODUCTION: Healthcare providers are increasingly searching for ways to provide cost-efficient, high-quality care. Previous studies on evaluating cost used estimated cost-to-charge ratios, which are inherently inaccurate. The purpose of this study was to quantify actual direct cost savings from performing pediatric orthopaedic sports day surgery at an ambulatory surgery center (ASC) compared with a university-based children's hospital (UH). METHODS: Custom-scripted accounting software was queried for line-item costs for a period of 3 fiscal years (fiscal year 2012 to fiscal year 2014) for eight day surgery procedures at both a UH and a hospital-owned ASC. Hospital-experienced direct costs were compared while controlling for surgeon, concomitant procedures, age, sex, and body mass index. RESULTS: One thousand twenty-one procedures were analyzed. Using multiple linear regression analysis, direct cost savings at the ASC ranged from 17% to 43% for seven of eight procedures. Eighty percent of the cost savings was attributed to time (mean, 64 minutes/case; P < 0.001) and 20% was attributed to supply utilization (P < 0.001). Of the time savings in the operating room, 73% (mean, 47 minutes; P < 0.001) was attributed to the surgical factors whereas 27% (17 minutes; P < 0.001) was attributed to anesthesia factors. CONCLUSIONS: Performing day surgery at an ASC, compared with a UH, saves 17% to 43% from the hospital's perspective, which was largely driven by surgical and anesthesia-related time expenditures in the operating room. LEVEL OF EVIDENCE: Level II.

Ambulatory Surgery Centers and Their Intended Effects on Outpatient Surgery.

OBJECTIVES: To assess the impact of ambulatory surgery centers (ASCs) on rates of hospital-based outpatient procedures and adverse events. DATA SOURCES: Twenty percent national sample of Medicare beneficiaries. STUDY DESIGN: A retrospective study of beneficiaries undergoing outpatient surgery between 2001 and 2010. Health care markets were sorted into three groups-those with ASCs, those without ASCs, and those where one opened for the first time. Generalized linear mixed models were used to assess the impact of ASC opening on rates of hospital-based outpatient surgery, perioperative mortality, and hospital admission. PRINCIPAL FINDINGS: Adjusted hospital-based outpatient surgery rates declined by 7 percent, or from 2,333 to 2,163 procedures per 10,000 beneficiaries, in markets where an ASC opened for the first time (p < .001 for test between slopes). Within these markets, procedure use at ASCs outpaced the decline observed in the hospital setting. Perioperative mortality and admission rates remained flat after ASC opening (both p > .4 for test between slopes). CONCLUSIONS: The opening of an ASC in a Hospital Service Area resulted in a decline in hospital-based outpatient surgery without increasing mortality or admission. In markets where facilities opened, procedure growth at ASCs was greater than the decline in outpatient surgery use at their respective hospitals.

Understanding the diffusion of ambulatory surgery centers.

BACKGROUND: Outpatient surgery is increasingly delivered at freestanding ambulatory surgery centers (ASCs), which are thought to deliver quality care at lower costs per episode. The objective of this study was to understand potential facilitators and/or barriers to the introduction of freestanding ASCs in the United States. METHODS: This is an observational study conducted from 2008 to 2010 using a 20% sample of Medicare claims. Potential determinants of ASC dissemination, including population, system, and legal factors, were compared between markets that always had ASCs, never had ASCs, and those that had new ASCs open during the study. Multivariable logistic regression was used to determine characteristics of markets associated with the opening of a new facility in a previously naïve market. RESULTS: New ASCs opened in 67 previously naïve markets between 2008 and 2010. ASCs were more likely to open in hospital service areas that were urban (adjusted odds ratio [OR], 4.10; 95% confidence interval [CI], 1.51-10.96), had higher per capita income (adjusted OR, 3.83; 95% CI, 1.43-10.45), and had less competition for outpatient surgery (adjusted OR, 2.13; 95% CI, 1.02-4.45). Legal considerations and latent need, as measured by case volumes of hospital-based outpatient surgery in 2007, were not associated with the opening of a new ASC. CONCLUSIONS: Freestanding ASCs opened in advantageous socioeconomic environments with the least amount of competition. Because of their associated efficiency advantages, policy makers might consider strategies to promote ASC diffusion in disadvantaged markets to potentially improve access and reduce costs.

Growth of ambulatory surgical centers, surgery volume, and savings to medicare.

We studied the impact of the growth of ambulatory surgical centers (ASCs) on total Medicare procedure volume and ASC market share from 2000 to 2009 for four common outpatient procedures: cataract surgery, upper gastrointestinal procedures, colonoscopy, and arthroscopy. ASC growth was not significantly associated with Medicare volume, except for colonoscopy. An additional ASC operating room per 100,000 population results in a 1.8% increase in colonoscopies performed in all outpatient settings. Increases in the number of ASCs were associated with greater ASC market share with effects ranging from 4- to 6-percentage-point gains for each additional ASC operating room per 100,000. The study demonstrates that continued growth of ASCs could reduce Medicare spending, because ASCs are paid a fraction of the amount paid to hospital outpatient departments for the same services.

A comparison of ambulatory perioperative times in hospitals and freestanding centers.

BACKGROUND: The volume of surgical procedures performed in ambulatory surgical centers has increased rapidly. METHODS: Ambulatory surgical visits of Medicare beneficiaries were compared for hospital-based and freestanding ambulatory surgical centers (ASCs). The main outcomes were time in surgery, time in operating room, time in postoperative care, and total perioperative time. RESULTS: The mean total perioperative time for all procedures examined was 39% shorter in freestanding ASCs then in hospital-based ASCs (83 vs 135 min; P < .01); surgery time was 37% shorter (19 vs 30 min; P < .01), operating room time was 37% shorter (34 vs 54 min; P < .01), and postoperative time was 35% shorter (48 vs 74 min; P < .01). CONCLUSIONS: Perioperative times were significantly shorter in freestanding ASCs than in hospital-based ASCs. It is unclear how much of the difference was the result of efficiency versus patient selection.