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David Robinson

Publications and source records attributed to David Robinson.

28 records · Page 2Linked to original sources
PubMed2003

Rapid magnetic resonance imaging vs radiographs for patients with low back pain: a randomized controlled trial.

CONTEXT: Faster magnetic resonance imaging (MRI) scanning has made MRI a potential cost-effective replacement for radiographs for patients with low back pain. However, whether rapid MRI scanning results in better patient outcomes than radiographic evaluation or a cost-effective alternative is unknown. OBJECTIVE: To determine the clinical and economic consequences of replacing spine radiographs with rapid MRI for primary care patients. DESIGN, SETTING, AND PATIENTS: Randomized controlled trial of 380 patients aged 18 years or older whose primary physicians had ordered that their low back pain be evaluated by radiographs. The patients were recruited between November 1998 and June 2000 from 1 of 4 imaging centers in the Seattle, Wash, area: a university-based teaching program, a nonuniversity-based teaching program, and 2 private clinics. INTERVENTION: Patients were randomly assigned to receive lumbar spine evaluation by rapid MRI or by radiograph. MAIN OUTCOME MEASURES: Back-related disability measured by the modified Roland questionnaire. Secondary outcomes included Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), pain, preference scores, satisfaction, and costs. RESULTS: At 12 months, primary outcomes of functional disability were obtained from 337 (89%) of the 380 patients enrolled. The mean back-related disability modified Roland score for the 170 patients assigned to the radiograph evaluation group was 8.75 vs 9.34 for the 167 patients assigned the rapid MRI evaluation group (mean difference, -0.59; 95% CI, -1.69 to 0.87). The mean differences in the secondary outcomes were not statistically significant : pain bothersomeness (0.07; 95% CI -0.88 to 1.22), pain frequency (0.12; 95% CI, -0.69 to 1.37), and SF-36 subscales of bodily pain (1.25; 95% CI, -4.46 to 4.96), and physical functioning (2.73, 95% CI -4.09 to 6.22). Ten patients in the rapid MRI group vs 4 in the radiograph group had lumbar spine operations (risk difference, 0.34; 95% CI, -0.06 to 0.73). The rapid MRI strategy had a mean cost of 2380 dollars vs 2059 dollars for the radiograph strategy (mean difference, 321 dollars; 95% CI, -1100 to 458). CONCLUSIONS: Rapid MRIs and radiographs resulted in nearly identical outcomes for primary care patients with low back pain. Although physicians and patients preferred the rapid MRI, substituting rapid MRI for radiographic evaluations in the primary care setting may offer little additional benefit to patients, and it may increase the costs of care because of the increased number of spine operations that patients are likely to undergo.

Activities of Daily Living↗
PubMed2003

A comparison of 50 initial endoluminal endograft repairs for abdominal aortic aneurysm with 50 concurrent open repairs.

PURPOSE: To review the results of our initial experience with endovascular repair of abdominal aortic aneurysm (AAA) with respect to morbidity and mortality and to compare these outcomes with those of transabdominal repair. METHODS: We reviewed the first 50 consecutive endovascular AAA repairs performed at our institution from November 1999 to January 2002. Pre-operative risk factors, intraoperative variables and post-operative outcomes were assessed. All endovascular patients were followed with periodic examination, contrast-enhanced computed tomography and/or duplex scanning. Comparison was made to 50 patients undergoing standard open repair over a similar time period. RESULTS: Fifty patients underwent endovascular AAA repair (mean age 72.5, AAA size 5.5 cm). Endovascular devices employed were manufactured by Ancure (Guidant Corp.), and AneuRx (Medtronic). Preoperative risk factors were similar to patients undergoing transabdominal repair. Mean operative time was 169 minutes and estimated blood loss was 450cc with average blood replacement of.18 units. Median ICU stay was 0 days and mean hospital stay was 2.3 nights. There were no conversions to open repair, however there was one aborted endovascular attempt. Morbidity included MI (2%), colon ischemia (1%), acute renal insufficiency (4%) and leg ischemia (4%). There was one death within 30 days. Seven endoleaks were identified (6 type II and 1 type I) and were managed angiographically. CONCLUSIONS: The short-term surgical morbidity and mortality rates for endovascular repair of AAA are acceptably low and are comparable to the transabdominal approach.

Aged↗
PubMed2003

Prognostic factors and survival in node-positive (N1) prostate cancer-a prospective study based on data from a Swedish population-based cohort.

OBJECTIVE: At presentation of prostate cancer, patients with proven lymph node metastasis (N1) are comparatively rare. It is difficult to give prognostic information based on the present literature. The aim of this study was to evaluate the impact of known risk factors in patients with pelvic node involvement and without distant metastasis. METHODS: From the population-based, prospective prostate cancer tumour registry of the South-East Region in Sweden, we collected data on all 181 patients with N1, M0 prostate cancer diagnosed from January 1987 to October 2000 with a follow-up to December 2001. Mean follow-up was 62 months. Pre-operative risk factors as age, T-category, serum PSA, tumour grade and also primary treatment given was correlated to the outcome. RESULTS: Median age at diagnosis was 65 years. Cancer-specific survival was highly variable with 5-year survival of 72%, a median of 8 years and the projected 13-year figure was 31%. T-category, age, PSA or treatment did not affect the outcome while poorly differentiated tumours had a tendency towards lower cancer-specific survival (p=0.0523) when compared to well and moderately differentiated tumours. CONCLUSIONS: This population-based cohort of prostate cancer patients with pelvic node involvement treated principally with non-curative intent had a median cancer-specific survival of 8 years. Preoperatively known risk factors seem to have but a modest impact on the prognosis for patients in this stage of the disease.

Adult↗
PubMed2003

Modelling cereal root systems for water and nitrogen capture: towards an economic optimum.

A quantitative model of wheat root systems is developed that links the size and distribution of the root system to the capture of water and nitrogen (which are assumed to be evenly distributed with depth) during grain filling, and allows estimates of the economic consequences of this capture to be assessed. A particular feature of the model is its use of summarizing concepts, and reliance on only the minimum number of parameters (each with a clear biological meaning). The model is then used to provide an economic sensitivity analysis of possible target characteristics for manipulating root systems. These characteristics were: root distribution with depth, proportional dry matter partitioning to roots, resource capture coefficients, shoot dry weight at anthesis, specific root weight and water use efficiency. From the current estimates of parameters it is concluded that a larger investment by the crop in fine roots at depth in the soil, and less proliferation of roots in surface layers, would improve yields by accessing extra resources. The economic return on investment in roots for water capture was twice that of the same amount invested for nitrogen capture.

Models, Theoretical↗
PubMed2002

Cancer clusters: findings vs feelings.

The issue of cancer clusters, which has been in the spotlight recently, is plagued by a wide disparity between public perceptions and scientific findings. Movies like Erin Brockovich have led the public to think that industrial pollution in the environment is causing local "cancer clusters" where cancer cases are more prevalent due to cancer-causing chemicals. There are many scientifically documented instances in which chemical exposure has caused cancer in humans, but the evidence for purely environmental exposures causing cancer is sparse. The clusters that scientists have been able to attribute successfully to a particular cause have been occupational (such as workers in a factory developing a particular type of cancer from daily exposure to a specific chemical), linked to a particular medicine, or linked to behaviors such as smoking or sunbathing. There is some indication that chemicals dissolved in drinking water may elevate the risk of gastrointestinal and bladder/urinary tract cancers and that living next to a smelter or other "point source" of air pollution may elevate risk of lung cancer. The many efforts that have been made to demonstrate links between other types of cancer and environmental contamination have not conclusively identified such links. Several challenges bedevil any cancer cluster investigation and can result in ambiguous or misleading conclusions. This report discusses the potential cancer clusters in Toms River, New Jersey and Long Island, New York, because they contain many elements typical of cancer cluster investigations and have received considerable media attention.

Bias↗
PubMed2002

A model of the direct and indirect effects of aprotinin administration on the overall costs of coronary revascularization surgery in a university teaching hospital cardiothoracic unit.

BACKGROUND: Cardiac patients sometimes bleed postoperatively and consequently require rethoracotomy, necessitating a longer stay in the intensive care unit (ICU) of the cardiothoracic unit (CTU). When ICU capacity is limited, rethoracotomy necessitates postponing treatment of the next patient. Aprotinin, a bovine lung-derived proteinase inhibitor, has been shown to reduce the frequency of rethoracotomies in cardiac patients. OBJECTIVE: This study was undertaken to quantify the reduction of potentially avoidable cost to the CTU of postoperative bleeding, both directly and indirectly, by administering aprotinin before and during coronary artery bypass graft (CABG). METHODS: A novel, validated operational research model was developed, featuring the principal CABG-related health care resource parameters believed to influence waiting lists and times. Factors and costs were derived from both local data from a CTU and relevant recent literature. RESULTS: According to the model, aprotinin therapy reduced the waiting list by approximately 3% by reducing the number of rethoracotomies. Using data from the literature, for an annual throughput of 431 patients who would receive aprotinin costing 97,333 pounds per year, the annual net savings to the CTU would be 46,586 pounds, which comprised direct savings on blood products of 35,036 pounds and indirect marginal savings of 11,550 pounds derived from 3.2% fewer rethoracotomies (each at a marginal cost of 837 pounds). By reason, then, reinvesting savings in increasing CTU capacity would yield further waiting-list reductions and improve patient morbidity. These results had 2 major limitations. First, it was assumed that all operations would have the same duration and all surgeons would perform operations in the same manner. Second, nonurgent patients were assumed to have been treated in order of strict referral sequence, which may not be done in real-world practice. CONCLUSIONS: Aprotinin reduced costs in CABG directly by reducing the use of blood products and indirectly by reducing waiting lists, as well as by reducing morbidity and mortality associated with waiting time.

Aprotinin↗
PubMed2002

Emergent treatment of a primary aortoenteric fistula with N-butyl 2-cyanoacrylate and endovascular stent.

A novel endovascular treatment involving cyanoacrylate injection followed by endovascular stent placement is described in the setting of life-threatening acute exsanguination through a primary aortoenteric fistula. In a patient in unstable condition, N-butyl 2-cyanoacrylate was injected into the fistula tract. Rapid polymerization first provided hemostasis and allowed the patient to be resuscitated and stabilized for several hours, and then an AneuRx endovascular stent-graft was deployed to reinforce the aortic wall and permanently occlude the fistula. This approach can benefit patients whose condition would otherwise be too unstable for open surgery.

Acute Disease↗