Office-based Laboratories Research Articles

Recent Trends in Clinical Setting and Provider Specialty for Endovascular Peripheral Artery Disease Interventions for the Medicare Population

PurposeTo describe national trends in peripheral endovascular interventions by physician specialty, anatomic segment of disease, and clinical location of service. Materials and MethodsCurrent Procedural Terminology codes were used to identify claims for peripheral vascular interventions (PVIs) in 2011–2017 Physician Supplier Procedure Summary master files, which contain 100% Part B Medicare billing. Market share was defined as enrollment-adjusted proportion of billed PVI services for each specialty. Annual volume of billed services was additionally evaluated by clinical location (inpatient, outpatient, office-based laboratories) and anatomic segment of disease (iliac, femoral/popliteal, infrapopliteal). ResultsAggregate PVI claims increased 31.3%, from 227,091 in 2011 to 298,127 in 2017. Annual market share remained relatively stable for all specialties: surgery, 48.3%–49.6%; cardiology, 37.2%–35.1%; radiology, 12.8%–13.3%. Accounting for Medicare enrollment, the volume of iliac interventions decreased by 18% over the study period, while femoral/popliteal interventions increased modestly (+7.5%) and infrapopliteal interventions increased (+46%). The greatest proportional increase in infrapopliteal claims occurred among radiologists (surgeons +40.4%, cardiologists +32.1%, radiologists +106.6%). Adjusting for enrollment, claims from office-based laboratories increased substantially (+305.7%), while hospital-based billing decreased (inpatient −25.7%, outpatient −12.9%). Office-based laboratory utilization increased dramatically with all specialties (surgery +331.8%, cardiology +256.0%, radiology +475.7%). ConclusionsUtilization of PVIs continues to increase, while specialty market shares have stabilized since 2011, leaving surgeons and cardiologists as the major providers of endovascular peripheral artery disease care. The greatest relative increases are occurring in infrapopliteal interventions and office-based laboratory procedures, where radiologist involvement has increased dramatically.

Initial financial impact of office-based laboratories on Medicare payments for percutaneous interventions for peripheral artery disease

ObjectivePercutaneous interventions for peripheral artery disease (PAD) are transitioning away from hospital-based settings to office-based laboratories (OBLs). Those in favor of OBL use reference lower hospitalization rates and high efficiency; however, critics claim financial incentives may lead to multiple procedures and higher atherectomy use. We sought to determine how Medicare payments are affected by OBL use. MethodsWe identified physicians performing percutaneous interventions for PAD from 2006 to 2013 in a 20% Medicare sample. Physicians performing a majority of interventions at OBLs were classified as high OBL users; control physicians performed interventions at hospital-based settings. The primary outcomes were total Medicare payments at 30 days and 1 year. Generalized log-gamma regression models were used to evaluate factors influencing payments reported as a percentage change and 95% confidence interval (95% CI). A secondary analysis was performed of physicians who transitioned from hospital-based settings to OBLs, “switch physicians.” A multivariate model with difference-in-differences regression was used to evaluate the effects of transitioning to OBLs. ResultsA total of 89 high OBL users performed percutaneous interventions on 887 patients, and 3715 control physicians treated 54,213 patients during the time period. Payments for patients treated by high OBL users were significantly higher compared with control physicians at 30 days ($4465), 90 days ($8925), and 1 year ($27,436). Major factors increasing payments at 1 year were treatment by a high OBL user (49%; 95% CI, 42%-56%), hospital admissions (127%; 95% CI, 123%-131%), repeated lower extremity procedures (41%; 95% CI, 39%-43%), and lower extremity wound (20%; 95% CI,18%-22%). Factors decreasing payments at 1 year were living in a rural setting (8%; 95% CI, 7%-9%) and dementia (5%; 95% CI, 3%-7%). Analysis of 292 switch physicians identified 3888 patients treated before OBLs (pre-switch) and 3246 after OBLs (post-switch). Transitioning to OBLs was associated with higher payments at 30 days and 90 days, and this increase was higher compared with control physicians. ConclusionsThese findings highlight that OBL use for PAD interventions significantly influences Medicare payments, and its widespread adaptation should be made with caution. The main factors driving payments were hospitalization admissions, repeated lower extremity procedures, and wound status. Further work is needed to evaluate the appropriate use of OBLs to optimize patient outcomes and resource allocations.

Assessing the Correlation Between a Surgeon's Ability to Draw a Procedure and Ability to Perform the Procedure

The ability to assess a trainee's technical skill in a manner that maintains patient safety is critical to resident education. To do so, senior plastic surgery educators frequently ask residents to draw their proposed operation, presuming that a surgeon's ability to perform a surgery is reflected in his or her ability to diagram the procedure, independent of artistic ability. The purpose of this study was to delineate the relationship between the ability to draw a surgical procedure and execute it in a simulated model, and to determine if the ability to draw a procedure depends on artistic ability. Participants in varying levels of knowledge and surgical skill were asked to draw a 4-strand cruciate tendon repair and subsequently perform the procedure on a validated, simulated model. The participants were graded according to Objective Structured Assessment of Technical Skills scales by 2 blinded hand surgeon examiners. Statistical analysis was performed in SAS 9.4 with Spearman's rank correlation coefficient. The study was performed at Baylor Scott and White Health in Temple, TX in an office-based laboratory setting. Participants Forty participants comprised of senior medical students, plastic/orthopedic surgery residents, and plastic/hand surgery attendings. All 40 participants entered and completed the study. A statistically significant strongly positive correlation was found between overall assessment of drawing and overall assessment of performing the surgical procedure (p = 0.004). At the same time, the assessment of ability to draw the procedure was not associated with a general ability to draw or previous art training (p = 0.28). Our findings support the use of drawing a specific procedure as an assessment tool to evaluate a surgeon's ability to perform a procedure.

Site of service influence on stent use for hemodialysis access interventions

ObjectiveWith rising health care spending in the United States, the Centers for Medicare and Medicaid Services (CMS) in recent years attempted to use reimbursement rates to influence use of less expensive care sites for covered patients, such as ambulatory surgery centers (ASCs) and office-based laboratories (OBLs), in lieu of hospital service sites. It has been suggested that cost savings have not been realized because of more procedures being performed by physicians with ownership interests in nonhospital facilities. CMS adopted massive reimbursement changes for 2019 OBL and ASC-based procedures, which reduced dialysis access angioplasty reimbursement in the ASC setting by 50%, whereas facility reimbursement for stenting increased by 33% above prior levels. The clinical utility of adjunctive stenting in treating dialysis access stenosis remains controversial and highly discretionary. As a vascular group performing such procedures in both a hospital and nonhospital facility in which we have equity interest, we reviewed our use of stents in dialysis access procedures both in the hospital and in the ASC/OBL to determine whether site of service affected stent use. MethodsA retrospective review of a prospectively maintained database was performed from 2014 to 2018. All patients undergoing dialysis access angiography with angioplasty and adjunctive stent placement at our OBL (later ASC) and our primary hospital were included in the study. ResultsThere were 961 angioplasty or stent procedures performed for dialysis accesses between the two sites, 564 (58.7%) in the hospital setting and 397 (41.3%) at the OBL/ASC. There was a significant difference in race and age between the two sites, with younger, minority patients more frequently being treated in the hospital and older, white patients more likely to be treated in the ambulatory setting; 153 (27.1%) underwent adjunctive stent placement in the hospital and 127 (32.0%) in the ambulatory setting (P = .09). ConclusionsWhereas financial incentives have not yet had an appreciable influence on stent use for dialysis access within previous reimbursement paradigms, the dramatic changes recently adopted by CMS may well alter this dynamic and could lead to substantially higher overall costs without proven clinical advantage. Interventionalists may be incentivized to add stents when performing balloon angioplasty in ASCs. With high failure and reintervention rates and increasingly expensive adjuncts (drug-coated balloons and stents, covered stents), the cost implications of attempts to incentivize interventionalists toward a specific type of procedure or site of care are substantial, and unintended negative consequences are likely to occur.

Impact of office-based laboratories on physician practice patterns and outcomes after percutaneous vascular interventions for peripheral artery disease

BackgroundPercutaneous vascular interventions (PVIs) for peripheral artery disease have shifted from hospital-based facilities to office-based laboratories (OBLs). The transition to OBLs is due to a variety of factors such as technology advancement, increased efficiency, and financial incentives. We evaluated the impact of physicians switching to OBLs use from hospital-based facilities on procedure volume, procedure type, and patient outcomes. MethodsWe identified patients with PVI for lower extremity peripheral artery disease from 2006 to 2013 in a 20% Medicare sample and identified physicians who transitioned from predominantly hospital-based facilities to OBLs (switch physicians) and compared them with those who did not use OBLs (control physicians). The main outcomes investigated were average number of PVIs at 30 days and 1 year and atherectomy usage. Patient outcomes included above-ankle amputation, major adverse limb events, and death. We used a difference-in-difference model to control for time effects in a multivariate regression model, reported as an odds ratio (OR) and 95% confidence interval (CI). ResultsThe cohort comprised 292 switch physicians, who treated 7134 patients (3888 before OBL use and 3246 after transitioning to OBLs), and 3715 control physicians treating 54,213 patients (36,327 in the preperiod and 17,886 in the postperiod). Switch and control physicians both treated more patients with lower extremity wounds during the study period; however, this increase was greater for control physician (0.7% vs 5.5%, P < .001). On average, patients treated by switch physicians had 0.05 (95% CI, 0.03-0.07; P < .001) underwent more PVIs within 30 days and 0.12 more PVIs (95% CI, 0.08-0.16; P < .001) within 1 year of the initial revascularization procedure after the physician transitioned to an OBL. Similarly, patients treated by switch physicians underwent 0.02 (95% CI, 0.01-0.03; P = .002) more atherectomy procedures at 30 days and 0.03 (95% CI, 0.01-0.05; P = .008) more atherectomy procedures at 1 year. Transitioning to OBLs was also associated with a decreased risk in above-ankle amputation at 30 days (OR, 0.58; 95% CI, 0.38-0.97; P = .009) and 1 year (OR, 0.75; 95% CI, 0.60-0.95; P = .01). However, no statistical difference was observed for major adverse limb events and mortality rates at 30 days and 1 year because patients treated by switch and control physicians experienced similar decreases. ConclusionsTransitioning to OBLs was associated higher 30-day and 1-year PVI rates and atherectomy rates. Although transitioning to OBLs was associated with lower rates of above-ankle amputations, switch physicians treated a lower number of patients with lower extremity wounds.

SS21. Impact of Office-Based Laboratories on Medicare Payments for Percutaneous Interventions for Peripheral Artery Disease

SS21. Impact of Office-Based Laboratories on Medicare Payments for Percutaneous Interventions for Peripheral Artery Disease

Provider Trends in Atherectomy Volume between Office-Based Laboratories and Traditional Facilities

As patient care is being increasingly transitioned out of the hospital and into the outpatient setting, there is a growing interest in developing office-based angiography suites, that is, office-based laboratories. Office-based care has been associated with increased efficiency and greater patient satisfaction, with substantially higher reimbursement directly to the physicians providing care. Prior studies have demonstrated a shift of revascularization procedures to office-based laboratories with a concomitant increase in atherectomy use, a procedure with disproportionately high reimbursement in comparison to other peripheral revascularization techniques. We sought to determine provider trends in endovascular procedure volume, settings, and shifts in practice over time, specific to atherectomy. Using Centers for Medicare & Medicaid Services Provider Utilization and Payment Data Public Use Files from 2013 to 2015, we identified providers who performed diagnostic angiography (DA), percutaneous transluminal angioplasty (PTA), stent placement (stent), and atherectomy, and procedures were aggregated at the provider level. Trends in procedures performed in office-based laboratory and facility-based settings were analyzed. Atherectomy was specifically analyzed using the total number and proportion of office-based laboratory procedures, and providers were stratified into quintiles by case volume. Between 2013 and 2015, 5,298 providers were identified. Over this time period, the number of providers performing atherectomy increased 25.7%, with the highest quintile of atherectomy providers performing an average of 263 cases (range 109-1,455). The proportion of physicians who performed atherectomy only in the office increased from 39.8% to 50.7% from 2013 to 2015, whereas only 20.8% of physicians who performed DA, PTA, or stent in 2015 did so only in an office-based laboratory. Of the physicians with the highest atherectomy volume, 77.8% operated only in the office in 2015, and these physicians increased their atherectomy volume to 114.1% during the study period. Of those physicians who transitioned to a solely office-based laboratory practice over the study period, atherectomy volume increased 63.4%, which was disproportionate compared with the growth of their DA, PTA, and stent volume. Over this short study period, a rapid shift into the office setting for peripheral intervention occurred, with a concomitant increase in atherectomy volume that was disproportionate to the increase in other peripheral interventions. This increase in office-based laboratory atherectomy occurred in the setting of increased reimbursement for the procedure and despite a lack of data supporting superiority over PTA/stent.

Impact of Physician-Owned Office-Based Laboratories on Physician Practice Patterns and Outcomes After Percutaneous Vascular Interventions for Peripheral Artery Disease

Percutaneous vascular interventions (PVIs) for peripheral artery disease have shifted from a hospital-based setting (HBS) to physician-owned office-based laboratories (OBLs). We sought to evaluate the changes of physicians’ treatment decisions and patients’ outcomes after the transition to OBLs. We identified patients with peripheral artery disease with PVI from 2006 to 2013 in a 20% Medicare sample and identified physicians who transitioned from predominantly HBS to OBLs (switch physicians) and compared them with those who performed procedures primarily in the HBS (control physicians). Patients’ outcomes included procedure type (balloon vs atherectomy vs stent), reintervention rates, major adverse limb events, hospitalizations, and mortality. We used a difference in difference model to control for time effects. The cohort comprised 290 switch physicians who treated 8011 patients (4373 before OBL and 3638 patients after the transition to OBL) and 3756 control physicians treating 53,629 patients (40,405 in the period before the transition and 13,224 in the period afterward). Patients’ demographics and indication for interventions are recorded in Table I. Switch physicians were observed to increase atherectomy use from 24% to 27% after the switch; however, the increase was larger for control physicians (20% to 30%; P < .001; Table II). Switching to OBL was independently associated with increased reintervention rates at 30 days and 1 year (P < .001), decreases in hospitalization rates at 30 days and 1 year (P < .001), and similar 30-day and 1-year mortality compared with control physicians. Differences for major adverse limb events were not statistically significant in controlling for patients’ demographics; however, the 30-day and 1-year amputation rates decreased at a greater rate after switching to OBL. Transition to OBLs was associated with lower amputation and hospitalization rates at the expense of increased 30-day and 1-year reintervention rates after PVI. Further study is warranted to evaluate the financial implications of OBLs to justify or to expand the current use.Table IPatients’ demographics and procedure indication by switch and control physiciansSwitch physicians (n = 290)Control physicians (n = 3756)P valueaPatients (n = 8011)Patients (n = 53,629)Age, years75.0 ± 9.675.23 ± 9.8***Male sex51.850.7NSCharlson Index5.8 ± 3.36.1 ± 3.4***ESRD10.612.0**Race Unknown<0.2<0.2*** White84.780.8 Black11.313.9 Other0.81.2 Asian0.60.8 Hispanic1.83.0 North American Native0.7<0.2Indication for intervention PAD + wound33.835.2NSESRD, End-stage renal disease; PAD, peripheral arterial disease.Categorical variables are presented as percentage. Continuous variables are presented as mean ± standard deviation.aNS, Not significant, P ≥ .05; *P < .05; **P < .01; ***P < .001. Open table in a new tab Table IIProcedure type and patients’ outcomes by switch and control physicians, stratified by periodSwitch physiciansControl physiciansP valueaBefore (n = 4373) vs after (n = 3638) switch, %Before (n = 40,405) vs after (n = 13,224) transition, %Type of first interventionb Balloon22.5 vs 23.2NS23.4 vs 19.0∗∗∗<.001 Stent53.2 vs 49.6∗∗56.7 vs 51.1∗∗∗.32 Atherectomy24.3 vs 27.2∗∗19.6 vs 29.9∗∗∗<.001Reintervention ratesc 30-day9.8 vs 14.9∗∗∗8.9 vs 8.8NS<.001 1- year28.8 vs 34.8∗∗∗25.3 vs 23.4∗∗<.001Atherectomy as subsequent procedurec 30-day3.7 vs 5.6 ∗∗∗2.5 vs 3.4 ∗∗∗.27 1-year10.6 vs 13.4∗∗∗8.3 vs 9.8∗∗∗.18MALEd 30-day5.7 vs 5.0NS5.7 vs 5.0∗∗.81 1-year15.6 vs 12.0∗∗∗14.6 vs 12.4∗∗∗.09Above-ankle amputationd 30-day2.5 vs 1.2%∗∗2.2 vs 2.2NS.002 1-year7.7 vs 4.6∗∗∗6.7 vs 5.6∗.001Hospitalizationd 30-day23.9 vs 18.0∗∗∗23.8 vs 22.9NS<.001 1-year61.0 vs 48.4∗∗∗58.9 vs 49.8∗∗∗.003MALE, Major adverse limb event.aDetermined by difference in difference analysis.bAdjusted for age, race, Charlson score, sex, wound.cAdjusted for procedure type.dAdjusted for reinterventions.NS, Not significant, P ≥ .05; *P < .05; **P < .01; ***P < .001. Open table in a new tab

IP197. Distal Retrograde Access for Infrainguinal Arterial Chronic Total Occlusions: A Prospective, Single-Center, Observational Study in the Office-Based Laboratory Setting

IP197. Distal Retrograde Access for Infrainguinal Arterial Chronic Total Occlusions: A Prospective, Single-Center, Observational Study in the Office-Based Laboratory Setting

Invited commentary

Invited commentary

Reimbursement, Particularly Atherectomy, Appears to Be a Principal Driver for Intervention for Lower Extremity Occlusive Disease, Particularly in Office-Based Laboratories

Reimbursement, Particularly Atherectomy, Appears to Be a Principal Driver for Intervention for Lower Extremity Occlusive Disease, Particularly in Office-Based Laboratories

Success of Atherectomy in Lower Extremity Ischemia Performed in Office-Based Laboratory

Success of Atherectomy in Lower Extremity Ischemia Performed in Office-Based Laboratory

The disproportionate growth of office-based atherectomy

ObjectiveThe purpose of this study was to evaluate the trends in procedure volume, clinical sites of care, and Medicare expenditure for peripheral vascular interventions (PVIs) for lower extremity occlusive disease since the Centers for Medicare and Medicaid Services instituted reimbursement policy changes that broadened payment for procedures performed in physician-owned office-based laboratories (OBLs). MethodsWe analyzed fee-for-service Medicare claims data from 2011 to 2014 to obtain the frequency of use of PVI by type, care setting, and physician specialty. We also assessed changes in the total Medicare cost for PVI by setting. ResultsThere was a 60% increase in atherectomy cases among Medicare beneficiaries between 2011 and 2014. During the same period, OBLs experienced a 298% increase in atherectomy volume vs a 27% increase in hospital outpatient settings and an 11% decrease for inpatient hospital settings. In 2014, OBLs were the most common setting for atherectomy. Nonatherectomy PVIs grew more modestly at just 3% but also experienced site of care shifts. Vascular surgeons and cardiologists accounted for the majority of office-based PVIs in 2014. Total Medicare costs for PVIs increased 18% from 2011 to 2014. Hospital inpatient costs declined 1%, whereas costs for hospital outpatient PVIs increased by 41% and physician office costs increased by 258%. ConclusionsThe migration of revascularization procedures for lower extremity peripheral arterial occlusive disease continues from the inpatient to the outpatient setting and especially to OBLs. Increased use of atherectomy in all segments of the lower extremity arterial system has been observed, particularly in OBLs, without substantial evidence in the literature of increased efficacy compared with standard angioplasty with or without stenting. Generous Medicare reimbursement for in-office atherectomy procedures is likely contributing to the volume shifts observed.

CRT-209 Procedural Outcomes of Orbital Atherectomy Treatment of Peripheral Arterial Disease in an Outpatient Office-Based vs. Hospital Setting

Despite the increasing use of atherectomy, few studies have compared outcomes of endovascular procedures performed in an outpatient office-based laboratory (OBL) to those performed in the traditional hospital setting. As the trend for increased outpatient treatment continues, it is critical to begin

Handheld Office-Based Spirometry versus Laboratory Spirometry in Low-Risk Patients Undergoing Lung Resection

Handheld Office-Based Spirometry versus Laboratory Spirometry in Low-Risk Patients Undergoing Lung Resection

Handheld Office-Based Spirometry versus Laboratory Spirometry in Low-Risk Patients Undergoing Lung Resection

To compare handheld office spirometry with laboratory spirometry in evaluation of low-risk patients undergoing pulmonary resection. Low-risk patients evaluated for lung resection were enrolled in a prospective study and underwent office and laboratory spirometry. Standard laboratory spirometry values were considered the gold standard. Values of forced expiratory volume in 1 second (FEV1) <1.5 L or FEV1% <60% were determined in advance to signal high risk. Thirty patients with mean age 64 ± 12 years and median Karnofsky performance status 100 (80-100) were evaluated. The mean FEV1-office spirometry and mean FEV1-laboratory spirometry were comparable (2.14 L vs 2.36 L) as were the mean FEV1%-office spirometry and FEV1%-laboratory spirometry (78% vs 85%). The differences were within limits established a priori. Laboratory spirometry identified 3 of 30 (10%) patients as high risk and office spirometry identified 5 of 30 (16%) patients as high risk, including the 3 patients identified by laboratory spirometry. The sensitivity of office spirometry for detecting high risk was 100% (3/3) and specificity was 93% (25/27). The negative predictive value of office spirometry was 100% (25/25). Office spirometry added a median of 1 minute to the office visit, whereas laboratory spirometry added 42 minutes. Eventually, 25 of 30 (83%) patients underwent lung resection. There were 12 lobar and 13 sublobar resections. One patient developed postoperative respiratory morbidity. This patient was high risk by office spirometry but not by laboratory spirometry. This patient was discharged on home oxygen. Office spirometry FEV1 and FEV1% are clinically comparable to formal laboratory spirometry values. Office Spirometry saves time and possibly expense in the preoperative workup of patients evaluated for lung resection.

Office-Based Vascular Lab: Is It Worth the Effort?

The vascular laboratory is an essential part of any contemporary clinical vascular practice. The prototype of the vascular laboratory consisted mainly of instruments designed to understand the hemodynamics of the vascular tree. Earlier versions also played important roles in clinical research. Currently, sophisticated imaging equipments enable clinicians to evaluate the whole range of arterial and venous diseases in the outpatient setting. Both patients and physicians have found this to be very practical and convenient. Furthermore, income generated from performing diagnostic tests in the vascular laboratory helps support a variety of clinical activities and research. However, recent cost-cutting measures by medical insurance carriers are threatening the viability of office-based vascular laboratories

Safety and feasibility of atropine added in patients with sub-maximal heart rate during exercise myocardial perfusion SPECT

Failure to reach 80% of maximal predicted heart rate (HR) during exercise may render a myocardial perfusion single photon emission computed tomography (SPECT) study non-diagnostic for ischemia detection. We sought to investigate the injection of atropine in patients who fail to achieve 80% of age-predicted HR during exercise performed for myocardial perfusion SPECT (MPS), defining its safety and efficacy to raise HR to adequate levels as well as its effect on MPS interpretation. Between January 2002 and December 2004, we studied 3,150 consecutive patients (2,253 men and 897 women, mean age 55 +/- 6 years) who were referred to a single office-based nuclear cardiology laboratory for MPS using SPECT imaging. One milligram of atropine was administered to patients that were unable to continue because of fatigue before reaching minimal HR, without an ischemic response (group A, n = 397). The scintigraphic results for group A were compared with those of patients who spontaneously achieved target HR (group B, n = 2,753). In group A, mean HR before atropine injection was 119.5 +/- 13.6 beats per minute (bpm), and it increased up to 137.3 +/- 13.5 bpm after drug administration, with an incremental of 17.8 +/- 6.9 bpm (P < 0.0001). The mean percentage of age-related HR achieved in this group was 83.5 +/- 8.1%. In 302 of this patients (76.1%) more than 80% of their aged-related HR (86.9 +/- 5.1%) was attained. No major adverse effects occurred. When groups A and B were compared, baseline and peak HR, rate pressure product, and maximal metabolic equivalents achieved were higher in group B. There were no significant differences in the percentage of total positive perfusion studies between both groups: 210/397 patients (52.9%) in group A and 1,342/2,753 patients (48.7%) in group B (P = 0.39). Ischemia or ischemia plus scar was found in 112/397 patients (28.2%) in group A and in 923/2,753 patients (33.5%) of group B (P = 0.14). Atropine added to exercise stress testing in patients who cannot achieve their 80% age-related HR is a safe, well-tolerated, and feasible method for MPS.

A national survey of practice patterns in the noninvasive diagnosis of deep venous thrombosis

Purpose: Recent studies have recommended unilateral venous duplex scanning for the diagnosis of deep venous thrombosis (DVT) in patients who are unilaterally symptomatic. Vascular laboratory accreditation standards, however, imply that bilateral leg scanning should be performed. We examined whether actual practice patterns have evolved toward limited unilateral scanning in such patients. Methods: A questionnaire was mailed to all 808 vascular laboratories in the United States that were accredited by the Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL). To encourage candid responses, the questionnaires were numerically coded and confidentiality was assured. Results: A total of 608 questionnaires (75%) were completed and returned. Most of the respondents (442; 73%) were either community-hospital or office-based laboratories, and the remaining 163 (27%) were university or affiliated-hospital laboratories. Most of the laboratories (460; 76%) had been in existence for 9 years or more, and 65% had been ICAVL–accredited in venous studies for 3 years or more. Board-certified vascular surgeons were the medical directors in 54% of the laboratories. Duplex ultrasound scanning was the diagnostic method used by 98% of the laboratories. In patients with unilateral symptoms, 75% of the laboratories did not routinely scan both legs for DVT. A large majority (75%) believe that bilateral scanning is not clinically indicated. Only 57 laboratories (14%) recalled having patients return with a DVT in the previously unscanned leg, with 93% of these laboratories reporting between one and five such patients. This observation correlated with larger volumes of venous studies performed by those laboratories ( P < .05). Similarly, only 52 laboratories (12%) recalled having patients return with subsequent pulmonary emboli. Of these laboratories, only five reported proximal DVT in the previously unscanned legs of such patients. Of all these laboratories, therefore, only 1% (5 of 443) have potentially missed the diagnosis of a DVT that caused a preventable pulmonary embolus with such a policy. Among those laboratories that always perform bilateral examinations, 41% do so because of habit. Most (61%) of the laboratories that perform bilateral scanning would do unilateral scanning if it were specifically approved by ICAVL. Conclusion: Three quarters of the ICAVL–accredited vascular laboratories perform limited single-extremity scanning for the diagnosis of DVT in patients with unilateral symptoms. This broad clinical experience suggests that this practice is widespread in selected patients. Clinical protocols should be established to provide guidelines for local laboratory implementation. (J Vasc Surg 1999;29:799-806.)

The physicians' office laboratory: 1988 and 1996 survey of Illinois pediatricians. Pediatric Practice Research Group.

To contrast practices of physicians' office laboratories in the years 1988 and 1996 and ascertain physicians' perception of the effect of the Clinical Laboratory Improvement Amendments of 1988 (CLIA). Mailed surveys to members of the Illinois chapter of the American Academy of Pediatrics in 1988 and 1996. There were 525 and 980 respondents in 1988 and 1996, respectively; analyses included 282 and 374 surveys representing offices where direct patient care was provided in a nonhospital setting. A paired analysis was also conducted on 101 offices that responded to both surveys. There was a decline from 1988 to 1996 in the percentage of offices doing in-office laboratory testing (93% to 84%, respectively; chi2 test; P<.01) and median number of types of tests (6 tests vs 4 tests; Mann-Whitney U test; P<.001). Decreases (chi2 test; P<.01) were seen in the proportion of offices offering throat culture for group A streptococci (63% to 33%), urinalysis (54% to 33%), urine culture (53% to 22%), rapid hemagglutination slide test for mononucleosis (42% to 17%), theophylline level (27% to 4%), and total cholesterol (22% to 13%). The proportion of offices offering urine dipstick, hematocrit or hemoglobin, complete blood cell count, and stool occult blood tests remained stable. For solo practitioner offices only, streptococcal antigen detection testing decreased (66% to 39%; chi2 test; P<.001). Findings in the paired analyses were similar. In 1996, more offices participated in a formal proficiency testing program (60% vs 11%; chi2 test; P<.001). The CLIA guidelines were deemed responsible for increased documentation (58%), discontinuing 1 or more tests (56%), increased frequency of quality control (50%), joining a proficiency program (40%), and increased cost to patients (32%). These surveys provide large-scale data concerning change in office-based laboratories of physicians serving children during an 8-year period. Office laboratories reduced their menu of tests and enhanced documentation and quality control for the tests that were done. Data like these in multiple specialties over time contribute to a comprehensive picture of the effects of CLIA on office laboratory practices.