Sexism in a UK-wide medical examination.

Gender bias and sexism in the health profession in the UK has been highlighted as a major problem. Efforts to reduce this must include medical training and examinations. The Situational Judgment Test (SJT) is an examination that must be passed to work as a foundation doctor in the UK; and is taken by all UK medical students. We analysed gender balance in all 215 scenarios included in the official practice papers for the SJT. We found that senior doctors were more than twice as likely to be men than women, while there was no significant gender difference in representation of foundation year-1 doctors, other health professionals or patients/relatives. This inequality has the potential to reinforce gender biases in healthcare. Medical examinations can, instead, represent an opportunity for prejudices to be challenged.

Association between antihypertensive treatment and adverse events: systematic review and meta-analysis.

OBJECTIVE: To examine the association between antihypertensive treatment and specific adverse events. DESIGN: Systematic review and meta-analysis. ELIGIBILITY CRITERIA: Randomised controlled trials of adults receiving antihypertensives compared with placebo or no treatment, more antihypertensive drugs compared with fewer antihypertensive drugs, or higher blood pressure targets compared with lower targets. To avoid small early phase trials, studies were required to have at least 650 patient years of follow-up. INFORMATION SOURCES: Searches were conducted in Embase, Medline, CENTRAL, and the Science Citation Index databases from inception until 14 April 2020. MAIN OUTCOME MEASURES: The primary outcome was falls during trial follow-up. Secondary outcomes were acute kidney injury, fractures, gout, hyperkalaemia, hypokalaemia, hypotension, and syncope. Additional outcomes related to death and major cardiovascular events were extracted. Risk of bias was assessed using the Cochrane risk of bias tool, and random effects meta-analysis was used to pool rate ratios, odds ratios, and hazard ratios across studies, allowing for between study heterogeneity (τ2). RESULTS: Of 15 023 articles screened for inclusion, 58 randomised controlled trials were identified, including 280 638 participants followed up for a median of 3 (interquartile range 2-4) years. Most of the trials (n=40, 69%) had a low risk of bias. Among seven trials reporting data for falls, no evidence was found of an association with antihypertensive treatment (summary risk ratio 1.05, 95% confidence interval 0.89 to 1.24, τ2=0.009). Antihypertensives were associated with an increased risk of acute kidney injury (1.18, 95% confidence interval 1.01 to 1.39, τ2=0.037, n=15), hyperkalaemia (1.89, 1.56 to 2.30, τ2=0.122, n=26), hypotension (1.97, 1.67 to 2.32, τ2=0.132, n=35), and syncope (1.28, 1.03 to 1.59, τ2=0.050, n=16). The heterogeneity between studies assessing acute kidney injury and hyperkalaemia events was reduced when focusing on drugs that affect the renin angiotensin-aldosterone system. Results were robust to sensitivity analyses focusing on adverse events leading to withdrawal from each trial. Antihypertensive treatment was associated with a reduced risk of all cause mortality, cardiovascular death, and stroke, but not of myocardial infarction. CONCLUSIONS: This meta-analysis found no evidence to suggest that antihypertensive treatment is associated with falls but found evidence of an association with mild (hyperkalaemia, hypotension) and severe adverse events (acute kidney injury, syncope). These data could be used to inform shared decision making between doctors and patients about initiation and continuation of antihypertensive treatment, especially in patients at high risk of harm because of previous adverse events or poor renal function. REGISTRATION: PROSPERO CRD42018116860.

Incorporating a brief intervention for personalised cancer risk assessment to promote behaviour change into primary care: a multi-methods pilot study.

BACKGROUND: Approximately 40% of cancers could be prevented if people lived healthier lifestyles. We have developed a theory-based brief intervention to share personalised cancer risk information and promote behaviour change within primary care. This study aimed to assess the feasibility and acceptability of incorporating this intervention into primary care consultations. METHOD: Patients eligible for an NHS Health Check or annual chronic disease review at five general practices were invited to participate in a non-randomised pilot study. In addition to the NHS Health Check or chronic disease review, those receiving the intervention were provided with their estimated risk of developing the most common preventable cancers alongside tailored behaviour change advice. Patients completed online questionnaires at baseline, immediately post-consultation and at 3-month follow-up. Consultations were audio/video recorded. Patients (n = 12) and healthcare professionals (HCPs) (n = 7) participated in post-intervention qualitative interviews that were analysed using thematic analysis. RESULTS: 62 patients took part. Thirty-four attended for an NHS Health Check plus the intervention; 7 for a standard NHS Health Check; 16 for a chronic disease review plus the intervention; and 5 for a standard chronic disease review. The mean time for delivery of the intervention was 9.6 min (SD 3) within NHS Health Checks and 9 min (SD 4) within chronic disease reviews. Fidelity of delivery of the intervention was high. Data from the questionnaires demonstrates potential improvements in health-related behaviours following the intervention. Patients receiving the intervention found the cancer risk information and lifestyle advice understandable, useful and motivating. HCPs felt that the intervention fitted well within NHS Health Checks and facilitated conversations around behaviour change. Integrating the intervention within chronic disease reviews was more challenging. CONCLUSIONS: Incorporating a risk-based intervention to promote behaviour change for cancer prevention into primary care consultations is feasible and acceptable to both patients and HCPs. A randomised trial is now needed to assess the effect on health behaviours. When designing that trial, and other prevention activities within primary care, it is necessary to consider challenges around patient recruitment, the HCP contact time needed for delivery of interventions, and how best to integrate discussions about disease risk within routine care.

Fidelity of the delivery of NHS Health Checks in general practice: an observational study.

BACKGROUND: The NHS Health Check programme aims to reduce the risk of common preventable diseases by providing risk information and behaviour change advice. Failure to deliver the consultation appropriately could undermine its efficacy. To date, to the authors' knowledge, there are no published data on the fidelity of delivery of NHS Health Checks. AIM: To assess the fidelity of delivery of NHS Health Checks in general practice. DESIGN & SETTING: Fidelity assessment of video and audio recordings of NHS Health Check consultations conducted in four GP practices across the East of England. METHOD: A secondary analysis of 38 NHS Health Check consultations, which were video or audio recorded as part of a pilot study of introducing discussions of cancer risk into NHS Health Checks. Using a checklist based on the NHS Health Check Best Practice Guidance, fidelity of delivery was assessed as the proportion of key elements completed during the consultations. RESULTS: The mean number of elements of the NHS Health Check completed across all consultations was 14.5/18 (80.6%), with a range of 10 to 17 (55.6% to 94.4%). The mean fidelity for risk assessment, risk communication, and risk management sections was 8.7/10 (87.0%), 4.1/5 (82.0%), and 1.7/3 (56.7%), respectively. Clinically appropriate lifestyle advice was given in 34/38 consultations. Elements with the lowest fidelity were ethnicity assessment (n = 12/38; 31.6%), family history of cardiovascular disease (CVD) assessment (n = 25/38; 65.8%), AUDIT-C communication (n = 13/38; 34.2%), and dementia risk management (n = 6/38; 15.8%). CONCLUSION: Although fidelity of delivery was high overall, important elements of the NHS Health Check were being regularly omitted. Opportunities for behaviour change, particularly relating to alcohol consumption and dementia risk management, may be being missed.

Bariatric Embolization: Pilot Study on the Impact of Gastroprotective Agents and Arterial Distribution on Ulceration Risk and Efficacy in a Porcine Model.

PURPOSE: To assess whether the number of fundal arteries embolized and use of gastroprotective agents have an impact on ghrelin suppression and gastric ulceration rates. MATERIALS AND METHODS: Twenty-two healthy, growing swine (mean, 38.4 kg; range, 30.3-47.0 kg) were evaluated. Six control swine underwent a sham procedure. Gastric embolization was performed by the infusion of 40-µm microspheres selectively into some or all gastric arteries supplying the gastric fundus. In group 1, 6 swine underwent embolization of all 4 arteries to the gastric fundus. In group 2, 5 swine underwent embolization of 2 gastric fundal arteries. In group 3, 5 swine underwent embolization of 1 gastric fundal artery. Animals in groups 2 and 3 were treated with gastroprotective agents (sucralfate and omeprazole). Weight and fasting plasma ghrelin levels were analyzed at baseline and at week 4. Upon animal euthanasia, gross analysis was performed for identification of ulcers. RESULTS: Only group 1 animals exhibited changes in serum ghrelin levels that rendered them significantly lower than those in control animals (P = .049). Group 3 animals exhibited marked elevations in serum ghrelin levels compared with control animals (P = .001). Gross pathologic evaluation revealed 0 ulcers in the control animals, 3 ulcers (50%) in group 1, 2 ulcers (40%) in group 2, and 2 ulcers (40%) in group 3. CONCLUSIONS: Administration of gastroprotective agents and embolization of fewer arteries to the gastric fundus did not prevent gastric ulceration in treated animals. Only animals that underwent embolization of all gastric arteries exhibited significant decreases in serum ghrelin levels.

Bariatric Radioembolization: A Pilot Study on Technical Feasibility and Safety in a Porcine Model.

PURPOSE: To evaluate feasibility of left gastric artery (LGA) yttrium-90 ((90)Y) radioembolization as potential treatment for obesity in a porcine model. MATERIALS AND METHODS: This study included 8 young female pigs (12-13 weeks, 21.8-28.1 kg). Six animals received infusions of (90)Y resin microspheres (46.3-105.1 MBq) into the main LGA and the gastric artery arising from the splenic artery. Animal weight and serum ghrelin were measured before treatment and weekly thereafter. Animals were euthanized 69-74 days after treatment, and histologic analyses of mucosal integrity and ghrelin immunoreactive cell density were performed. RESULTS: Superficial mucosal ulcerations < 3.0 cm(2) were noted in 5 of 6 treated animals. Ghrelin immunoreactive cell density was significantly lower in treated versus untreated animals in the stomach fundus (13.5 vs 34.8, P < .05) and stomach body (11.2 vs 19.8, P < .05). Treated animals gained less weight than untreated animals over the study duration (40.2 kg ± 5.4 vs 54.7 kg ± 6.5, P = .053). Average fundic parietal area (165 cm(2) vs 282 cm(2), P = .067) and average stomach weight (297.2 g vs 397.0 g, P = .067) were decreased in treated versus untreated animals. Trichrome staining revealed significantly more fibrosis in treatment animals compared with control animals (13.0 vs 8.6, P < .05). No significant differences were identified in plasma ghrelin concentrations (P = .24). CONCLUSIONS: LGA (90)Y radioembolization is promising as a potential treatment for obesity. A larger preclinical study is needed to evaluate the safety and efficacy of this procedure further.

How Sensitive Is the Upper Gastrointestinal Tract to 90Y Radioembolization? A Histologic and Dosimetric Analysis in a Porcine Model.

In 90Y radioembolization, nontarget embolization to the stomach or small bowel can result in gastrointestinal injury, a rare but difficult to manage clinical complication. However, dosimetric thresholds for toxicity to these tissues from radioembolization have never been evaluated in a controlled setting. We performed an analysis of the effect of 90Y radioembolization in a porcine model at different absorbed-dose endpoints. METHODS: Six female pigs underwent transfemoral angiography and infusion of 90Y-resin microspheres into arteries supplying part of the gastric wall. Esophagogastroduodenoscopy was performed after 4 wk to assess interim gastrointestinal health. Animals were monitored for side effects for 9 wk after 90Y infusion, after which they were euthanized and their upper gastrointestinal tracts were excised for analysis. Histologic sections were used to map microsphere location, and a microdosimetric evaluation was performed to determine the absorbed-dose profile within the gastrointestinal wall. RESULTS: 90Y radioembolization dosages from 46.3 to 105.1 MBq were infused, resulting in average absorbed doses of between 35.5 and 91.9 Gy to the gastric wall. No animal exhibited any signs of pain or gastrointestinal distress through the duration of the study. Excised tissue showed 1-2 small (<3.0 cm2) healed or healing superficial gastric lesions in 5 of 6 animals. Histologic analysis demonstrated that lesion location was superficial to areas of abnormally high microsphere deposition. An analysis of microsphere deposition patterns within the gastrointestinal wall indicated a high preference for submucosal deposition. Dosimetric evaluation at the luminal mucosa performed on the basis of microscopic microsphere distribution confirmed that 90Y dosimetry techniques conventionally used in hepatic dosimetry provide a first-order estimate of absorbed dose. CONCLUSION: The upper gastrointestinal tract may be less sensitive to 90Y radioembolization than previously thought. Lack of charged-particle equilibrium at the luminal mucosa may contribute to decreased toxicity of 90Y radioembolization compared with external-beam radiation therapy in gastrointestinal tissue. Clinical examples of injury from 90Y nontarget embolization have likely resulted from relatively large 90Y activities being deposited in small tissue volumes, resulting in absorbed doses in excess of 100 Gy.

Bariatric embolization of the gastric arteries for the treatment of obesity.

Obesity is a public health epidemic in the United States that results in significant morbidity, mortality, and cost to the health care system. Despite advancements in therapeutic options for patients receiving bariatric procedures, the number of overweight and obese individuals continues to increase. Therefore, complementary or alternative treatments to lifestyle changes and surgery are urgently needed. Embolization of the left gastric artery, or bariatric arterial embolization (BAE), has been shown to modulate body weight in animal models and early clinical studies. If successful, BAE represents a potential minimally invasive approach offered by interventional radiologists to treat obesity. The purpose of the present review is to introduce the interventional radiologist to BAE by presenting its physiologic and anatomic bases, reviewing the preclinical and clinical data, and discussing current and future investigations.

Effects of model-based iterative reconstruction on image quality for low-dose computed tomographic angiography of the thoracic aorta in a Swine model.

PURPOSE: The aim of the study was to assess the image quality of multi-detector-row computed tomography (CT) angiographic images of the thoracic aorta reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) at different kVp and mA settings. METHODS: A healthy 56.1-kg Yorkshire pig underwent sequential arterial CT angiograms on a 64-slice multi-detector-row CT scanner (Discovery CT 750HD; GE Healthcare Inc, Milwaukee, Wis) at progressively lower kVp and mA settings. At 120-, 100-, and 80-kVp levels, the pig was scanned at 700, 400, 200, 100, and 50 mA at, for a total of 15 scans. Each scan was reconstructed with FBP, adaptive statistical iterative reconstruction (50% blend), and MBIR. Relative noise and contrast-to-noise ratio (CNR) were calculated from regions of interest over the aorta and paraspinous muscle. In addition, selected axial and oblique sagittal images were scored subjectively for both aortic wall visibility and for overall image quality. RESULTS: Averaged across all kVp and mA variations, MBIR reduced relative noise by 73.9% and improved CNR by 227% compared with FBP; MBIR reduced relative noise by 63.4% and improved CNR by 107% compared with ASIR. The effects were more pronounced in lower tube output settings. At 100 kVp/700 mA, MBIR reduced noise by 57% compared with FBP and 40% compared with ASIR. At 100 kVp/50 mA, MBIR reduced noise by 82% compared with FBP and 75% compared with ASIR. Subjective improvements in image quality were noted only in higher noise settings. CONCLUSIONS: Model-based iterative reconstruction reduces relative noise and improves CNR compared with ASIR and FBP at all kVp and mA settings, which were significantly greater at lower mA settings.

Bacteriophage K antimicrobial-lock technique for treatment of Staphylococcus aureus central venous catheter-related infection: a leporine model efficacy analysis.

PURPOSE: To determine whether a bacteriophage antimicrobial-lock technique can reduce bacterial colonization and biofilm formation on indwelling central venous catheters in a rabbit model. MATERIALS AND METHODS: Cuffed central venous catheters were inserted into the jugular vein of female New Zealand White rabbits under image guidance. Catheters were inoculated for 24 hours with broth culture of methicillin-sensitive Staphylococcus aureus. The inoculum was aspirated, and rabbits were randomly assigned to two equal groups for 24 hours: (i) untreated controls (heparinized saline lock), (ii) bacteriophage antimicrobial-lock (staphylococcal bacteriophage K, propagated titer > 10(8)/mL). Blood cultures were obtained via peripheral veins, and the catheters were removed for quantitative culture and scanning electron microscopy. RESULTS: Mean colony-forming units (CFU) per cm(2) of the distal catheter segment, as a measure of biofilm, were significantly decreased in experimental animals compared with controls (control, 1.2 × 10(5) CFU/cm(2); experimental, 7.6 × 10(3); P = .016). Scanning electron microscopy demonstrated that biofilms were present on the surface of five of five control catheters but only one of five treated catheters (P = .048). Blood culture results were not significantly different between the groups. CONCLUSIONS: In a rabbit model, treatment of infected central venous catheters with a bacteriophage antimicrobial-lock technique significantly reduced bacterial colonization and biofilm presence. Our data represent a preliminary step toward use of bacteriophage therapy for prevention and treatment of central venous catheter-associated infection.

Histopathologic and immunohistochemical sequelae of bariatric embolization in a porcine model.

PURPOSE: To evaluate the histopathologic sequelae of bariatric embolization on the gastric mucosa and to correlate with immunohistochemical evaluation of the gastric fundus, antrum, and duodenum. MATERIALS AND METHODS: This study was performed on 12 swine stomach and duodenum specimens after necropsy. Of the 12 swine, 6 had previously undergone bariatric embolization of the gastric fundus, and the 6 control swine had undergone a sham procedure with saline. Gross pathologic, histopathologic, and immunohistochemical examinations of the stomach and duodenum were performed. Specifically, mucosal integrity, fibrosis, ghrelin-expressing cells, and gastrin-expressing cells were assessed. RESULTS: Gross and histopathologic evaluation of treatment animals showed healing or healed mucosal ulcers in 50% of animals, with gastritis in 100% of treatment animals and in five of six control animals. The ghrelin-immunoreactive mean cell density was significantly lower in the gastric fundus in the treated animals compared with control animals (15.3 vs 22.0, P < .01) but similar in the gastric antrum (9.3 vs 14.3, P = .08) and duodenum (8.5 vs 8.6, P = .89). The gastrin-expressing cell density was significantly lower in the antrum of treated animals compared with control animals (82.2 vs 126.4, P = .03). A trend toward increased fibrosis was suggested in the gastric fundus of treated animals compared with controls (P = .07). CONCLUSIONS: Bariatric embolization resulted in a significant reduction in ghrelin-expressing cells in the gastric fundus without evidence of upregulation of ghrelin-expressing cells in the duodenum. Healing ulcerations in half of treated animals underscores the need for additional refinement of this procedure.

Bacteriophage K for reduction of Staphylococcus aureusbiofilm on central venous catheter material.

The purpose of this project was to determine whether bacteriophage can reduce bacterial colonization and biofilm formation on central venous catheter material. Twenty silicone discs were inoculated for 24 h with broth culture of Methicillin sensitive staphylococcus aureus (0.5 McFarland standard). The inoculate was aspirated and discs placed into two equal groups for 24 h: (1) untreated controls; (2) bacteriophage treatment (staphylococcal bacteriophage K, propagated titer > 108). At the completion of the experiment discs were processed for quantitative culture. Statistical testing was performed using the rank sum test. Mean colony forming units (CFU) were significantly decreased in experimental compared with controls (control 6.3 × 105 CFU, experimental 6.7 × 101, P ≤ 0.0001). Application of bacteriophage to biofilm infected central venous catheter material significantly reduced bacterial colonization and biofilm presence. Our data suggests that bacteriophage treatment may be a feasible strategy for addressing central venous catheter staph aureus biofilm infections.

Physician self-referral: frequency of negative findings at MR imaging of the knee as a marker of appropriate utilization.

PURPOSE: To determine whether ownership of magnetic resonance (MR) imaging equipment by ordering physicians affects the likelihood of positive findings at MR imaging of the knee and to evaluate rates of knee abnormalities seen at MR imaging as a metric for comparison of utilization. MATERIALS AND METHODS: The institutional review board approved this retrospective HIPAA-compliant study and waived the need for informed consent. A retrospective review was performed of consecutive diagnostic MR images of the knee interpreted by one radiology practice between January and April 2009 for patients who had been referred by two separate physician groups serving the same geographic community: one with financial interest (FI) in the MR imaging equipment used and one with no FI (NFI) in the MR imaging equipment used. The percentage of examinations with negative results was tabulated for both groups, and the relative frequency of each abnormality subtype was calculated among the studies with positive findings in each group. To examine frequency differences among groups, χ(2) tests were used, and to examine mean differences among groups, t tests were used. RESULTS: Of 700 examinations, 205 had negative results (117 of 350 in the FI group and 88 of 350 in the NFI group, P = .016). Among the examinations with positive results, the mean total number of positive abnormality subtypes per image did not significantly differ between groups: 1.52 for the FI group and 1.53 for the NFI group (P = .96). CONCLUSION: MR images of the knee among patients referred by the FI group were significantly more likely to be negative than those among patients referred by the NFI group. Frequency of abnormality subtype and distribution among examinations with positive results suggests a highly similar distribution and severity of abnormalities between the two patient groups.

Journal Club: Shoulder MRI utilization: relationship of physician MRI equipment ownership to negative study frequency.

OBJECTIVE: The purpose of this article is to determine whether ownership of MRI equipment by ordering physicians influences the frequency of negative shoulder MRI scans. MATERIALS AND METHODS: A retrospective review was performed of 1140 consecutive shoulder MRI scans ordered by two separate referring physician groups serving the same geographic community. The first group (financially incentivized) owned the scanners used and received technical fees for their use. The second group (non-financially incentivized) did not own the scanners used and had no direct financial interest. All examinations were performed with identical protocols and were interpreted by a single radiologist group without financial interest in the imaging equipment used. The frequency of negative examinations and the number of abnormalities in each positive study was tabulated for each group. RESULTS: A total of 1140 shoulder MRI scans met inclusion criteria; 255 were negative (142 for the financially incentivized group and 113 for the non-financially incentivized group). There were 25.6% more negative scans in the financially incentivized group (p=0.047). There was no statistically significant difference in the average number of lesions per positive scan (1.67 for the financially incentivized group and 1.71 for the non-financially incentivized group; p=0.34). No statistically significant difference was found in the frequency of 19 of 20 examined lesions. CONCLUSION: Shoulder MRI examinations referred by physicians with a financial interest in the imaging equipment used were significantly more likely to be negative. Positive examinations exhibited no statistically significant difference in the number of lesions per scan or in the frequency of 19 of 20 lesion subtypes. This finding suggests a highly similar distribution and severity of disease among the two patient groups.

Bariatric embolization for suppression of the hunger hormone ghrelin in a porcine model.

PURPOSE: To prospectively test in a porcine model the hypothesis that bariatric embolization with commercially available calibrated microspheres can result in substantial suppression of systemic ghrelin levels and affect weight gain over an 8-week period. MATERIALS AND METHODS: The institutional animal care and use committee approved this study. Twelve healthy growing swine (mean weight, 38.4 kg; weight range, 30.3-47.0 kg) were evaluated. Bariatric embolization was performed by infusion of 40-µm calibrated microspheres selectively into the gastric arteries that supply the fundus. Six swine underwent bariatric embolization, while six control animals underwent a sham procedure with saline. Weight and fasting plasma ghrelin and glucose levels were obtained in animals at baseline and at weeks 1-8. Statistical testing for differences in serum ghrelin levels and weight at each time point was performed with the Wilcoxon signed rank test for intragroup differences and the Wilcoxon rank sum test for intergroup differences. RESULTS: The pattern of change in ghrelin levels over time was significantly different between control and experimental animals. Weekly ghrelin levels were measured in control and experimental animals as a change from baseline ghrelin values. Average postprocedure ghrelin values increased by 328.9 pg/dL ± 129.0 (standard deviation) in control animals and decreased by 537.9 pg/dL ± 209.6 in experimental animals (P = .004). The pattern of change in weight over time was significantly different between control and experimental animals. The average postprocedure weight gain in experimental animals was significantly lower than that in control animals (3.6 kg ± 3.8 vs 9.4 kg ± 2.8, respectively; P = .025). CONCLUSION: Bariatric embolization can significantly suppress ghrelin and significantly affect weight gain. Further study is warranted before this technique can be used routinely in humans.

Effect on examination ordering by physician attitude, common knowledge, and practice behavior regarding CT radiation exposure.

PURPOSE: We surveyed ordering physician attitudes, knowledge, and behavior with regard to computed tomography (CT)-related radiation exposure at a large medical center. METHODS: Sixteen questions were sent via electronic survey to 350 physicians. RESULTS AND CONCLUSION: The ability to quickly rule in or rule out conditions effectively strongly influenced the decision to order CT (85%-99%). Fear of litigation influenced CT ordering for those with less experience [odds ratio (OR)=2.3, P<.05]. Residents and primary care physicians were less likely to discuss risks/benefits of CT with patients (P ≤.03) compared to those with >5 years of experience (OR=4.0, P=.04).

Physician self-referral of lumbar spine MRI with comparative analysis of negative study rates as a marker of utilization appropriateness.

OBJECTIVE: Financial interest in imaging equipment may affect the imaging referral patterns of ordering physicians. The purpose of this article is to determine whether ownership of MRI equipment by ordering physicians predicts the likelihood and prevalence of positive findings on lumbar spine MRI as a metric for comparison of utilization. MATERIALS AND METHODS: A retrospective review was performed of 500 consecutive diagnostic lumbar spine MRI examinations in one radiology practice ordered by two separate referring physician groups serving the same geographic community: one with financial interest in the MRI equipment used (financial-interest group) and one without financial interest in the MRI equipment used (no-financial-interest group). Negative examinations and total number of lesions per positive study were recorded for each group. RESULTS: Five hundred scans met inclusion criteria during the study period (250 in the financial-interest group and 250 in the no-financial-interest group). The negative scan frequency was 86% higher in the financial-interest group (p < 0.0001). Among positive scans, there was no significant difference in the average total number of positive lesions per scan (3.93 for the financial-interest group and 4.31 for the no-financial-interest group; p = 0.132). The average age of patients imaged by the financial-interest group was 49.8 years, versus 56.9 years for the no-financial-interest group (p < 0.0001). CONCLUSION: Lumbar spine MRI examinations referred by the financial-interest group were significantly more likely to be negative than those referred by the no-financial-interest group. Lesion frequency among positive scans suggests similar severity of disease between the two patient populations. Patients imaged by the financial-interest group were significantly younger than those imaged by the no-financial-interest group.

Self-referral in medical imaging: a meta-analysis of the literature.

PURPOSE: In the current political and economic climate, there is a desire to reduce health care costs; diagnostic imaging expenditure is one area of particular interest. The authors present a meta-analysis of the relative frequency of imaging utilization in the setting of self-referral compared with that of non-self-referral and a simulation of increased cost to Medicare Part B on the basis of this relative frequency. METHODS: The MEDLINE database was searched systematically. Specific inclusion criteria for relative frequency calculations were a numerator (number of patients imaged) and denominator (number of total patients seen) in each group (self-referrers and radiologist referrers). The relative risk of self-referral was determined for each group and is defined by the "relative frequency" of imaging utilization for the self-referrers divided by the frequency for the radiologist referrers. Relative frequency represents the increased (if >1) or decreased (if <1) chance of imaging by self-referrers over radiologist referrers. The meta-analysis was used to combine imaging frequencies for each referral condition of the individual studies that met inclusion criteria for an overall estimate of relative frequency, using a random-effects model to account for the variations among the studies. Relative frequency data were then used to perform a cost simulation to Medicare Part B using 2006 data. RESULTS: The initial search yielded 334 articles, 5 of which met the threshold for inclusion. In these 5 studies, 76,905,162 total episodes of care were analyzed. The individual relative frequency of imaging in the setting of self-referral ranged from 1.60 to 4.50. The combined relative frequency was 2.16 (95% confidence interval, 2.15-2.16) using the fixed-effects model and 2.48 (95% confidence interval, 1.90-3.24) using the random-effects model. For 2006 Government Accountability Office (GAO) data, the estimated cost of increased imaging in the setting of self-referral was $3.6 billion, but a range of costs was also provided to account for potential inaccuracies in the GAO data. CONCLUSIONS: The existing literature yields a combined relative frequency of imaging of 2.48 (95% confidence interval, 1.90-3.24) for self-referrers compared with non-self-referrers. Precise extrapolation of Medicare Part B costs attributable to self-referral would require changes in reporting requirements for imaging equipment ownership. Cost simulation results total billions of dollars annually and may be irrespective of potential inaccuracies in the GAO data as a result of Current Procedural Terminology(®) coding ambiguity and nontransparent reporting of equipment ownership.