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PubMed2004

Standards for online teaching: lessons from the education, health and IT sectors.

Online teaching is a growing, but not a new, phenomenon. It is most associated with distance education, but it also features in classroom education, in the form of blended learning. During this period of growth in online teaching, there has been time for the development of standards to ensure its quality. Yet the standards that have emerged tend to be derivatives of the standards for conventional, classroom teaching. They do not adequately address the specific demands of online education. Is this acceptable for online teachers? Is it supportive of online students? This contribution to the debate outlines how nurse educators can generate--and are generating--credible standards for their online practice. It identifies flaws in the current guidance for online teachers. It points out that knowledge of standard setting in the health service can support standard setting in higher education. And it highlights that the most useful guidance for the online teacher comes not from the education sector but from the industrial sector, specifically from the IT industry. It finishes on a practical note, describing how nurse educators in the University of Paisley are using these findings to develop standards for their online teaching practice.

Computer-Assisted Instruction↗
PubMed2006

The role of virtual standards in visual discrimination.

Psychometric functions were measured in various visual discrimination tasks involving test stimuli whose values spanned a standard stimulus. In two-interval trial blocks, the standard was either always in the first or always in the second interval, or appeared randomly in either interval. In one-interval blocks, the standard stimulus was never presented. Fitting the data with cumulative Gaussian functions revealed that discriminability was highest on one interval trials, where the observer had to rely on an implicit standard. On two-interval trials, discriminability was higher when the standard was in the first rather than the second interval, regardless of whether those two types of trials were intermixed or not, also possibly implicating the operation of an implicit standard in two-interval trials as well. A time-order error occurs on two-interval trials: in effect the value of the stimulus presented in the first interval is underestimated relative to that in the second interval. An analogous error occurs in one-interval trials, as if there were an implicit standard whose value is underestimated.

Discrimination, Psychological↗
PubMed1999

The prevalence of non-standard helmet use and head injuries among motorcycle riders.

OBJECTIVES: This study examined the prevalence of non-standard helmet use among motorcycle riders following introduction of a mandatory helmet use law and the prevalence of head injuries among a sample of non-standard helmet users involved in motorcycle crashes. METHODS: Motorcycle rider observations were conducted at 29 statewide locations in the 2 years following the introduction of the mandatory helmet use law in January, 1992. Medical records of motorcyclists who were injured in 1992 for whom a crash report was available and for whom medical care was administered in one of 28 hospitals were reviewed. Chi-squares and analysis of variance were used to describe differences between groups. RESULTS: Prevalence of non-standard helmet use averaged 10.2%, with a range across observation sites from 0 to 48.0%. Non-standard helmet use varied by type of roadway, day of week, and time of day. Injuries to the head were more frequent and of greater severity among those wearing non-standard helmets than both those wearing no helmet and those wearing standard helmets. CONCLUSIONS: Non-standard helmets appear to offer little head protection during a crash. Future study is needed to understand the dynamics leading to head injury when different types of helmets are worn.

Accidents, Traffic↗
PubMed1998

The American Dietetic Association Standards of Professional Practice for dietetics professionals.

The Standards of Professional Practice reflect changing market trends, transitions in the work environment, and expectations of the public. The 6 professional standards encompass the key characteristics of the dietetics profession. ADA's mission to serve the public is supported when each dietetics professional applies the 6 Standards of Professional Practice and evaluates the quality of services he or she provides. The standards belong to each and every dietetics professional. They are scheduled for periodic review and revision as the needs of the dietetics profession change. Throughout their careers, dietetics professionals will be called on to contribute to the continuous improvement of these standards and the dietetics profession. It is the responsibility of each individual practitioner to evaluate practice and maintain competence as well as to evaluate the professional standards and contribute to the advancement of the dietetics profession. The Standards of Professional Practice should be adopted by all dietetics professionals to ensure that they will continue to be recognized by the public as the most valued and credible sources of food and nutrition information.

Dietetics↗
PubMed2000

Orthotopic heart transplantation: standard versus bicaval technique.

We compared orthotopic heart transplantation (HT) by bicaval technique with the standard technique. Between January 1995 and December 1997, 117 patients underwent 118 HTs; 71 patients (15 women and 56 men) had 72 HTs by standard technique and 46 patients (9 women, 37 men) underwent HT using bicaval procedures. Preoperative parameters were similar in both groups; 5 patients who underwent the standard technique and no patients who underwent bicaval procedures required permanent pacemakers (p = NS). Isoproterenol infusion was significantly longer in the standard technique. Major perioperative arrhythmias (ventricular tachycardia and fibrillation, asystole) appeared in 8.2% and 7.0% of standard and bicaval HTs, respectively; atrial fibrillation appeared in 13.1% and 4.6%, respectively (p = NS). At 1 month, mitral and tricuspid regurgitation rates were higher in the standard group (p = NS); at 1 year only tricuspid regurgitation was still higher (p = NS). Right atrial pressure, Wood units, cardiac output, and cardiac index were examined (p = NS). At multivariate analysis, interaction between preoperative Wood units and transplant type was elicited for Wood units at 1 month and for right atrial pressure at 1, 3, and 6 months. In the high resistance subgroup, the patients who underwent bicaval procedures had higher resistances at 1 month. In the low resistance subgroup, right atrial pressure was higher in patients who underwent standard techniques at 1, 3, and 6 months follow-up. Thus, bicaval HT was found to be safe, without surgically related complications, it provoked significantly less blood loss, and required less isoproterenol use. No significant advantages were observed in conduction disturbances and major arrhythmias or regarding the need for temporary or permanent pacemakers.

Adolescent↗
PubMed1999

External compression dressing versus standard dressing after axillary lymphadenectomy.

BACKGROUND: Closed-catheter drainage after axillary lymph node dissection (ALND) for breast cancer may constitute a significant inconvenience to the recovering patient, and may also serve as portals of entry for bacteria. Any intervention that could reduce the volume and duration of postoperative drainage would be beneficial. The purpose of this study was to determine whether an external compression dressing after ALND would decrease postoperative drainage, afford earlier drain removal, and reduce subsequent seroma formation. PATIENTS AND METHODS: One hundred thirty-five women undergoing definitive surgical treatment for breast cancer were randomized to receive a compression dressing (n = 66) or standard dressing (n = 69). They were also stratified for modified radical mastectomy (MRM; n = 74) or breast conservation therapy (BCT; n = 61). All patients had ALND. The compression dressing consisted of a circumferential chest wrap of two 6-inch Ace bandages, held in place by circumferential Elastoplast bandage, and it was applied by the same nurse. This dressing remained intact until postoperative day 4. Patients in the standard dressing group (control) were fitted with a front-fastening Surgibra only. Drains were removed when the total daily amount was <50 cc. Postoperative drainage volume, total days with drain, and frequency of seroma formation were recorded for each patient. RESULTS: After 4 days, wound drainage in both groups was nearly identical (compression = 490 cc, standard = 517 cc; P = 0.48). Total days with drain were also similar (compression = 6.4 days, standard = 6.1 days; P = 0.69). The compression dressing did not reduce seroma formation. In fact, there was a statistically significant increase in the number of seroma aspirations per patient in the compression group (compression = 2.9, standard = 1.8; P <0.01). The increase in seroma aspirations was more significant in MRM patients (compression = 3.1, standard = 1.7; P <0.01) than in BCT patients (compression = 2.6, standard = 1.8; P = 0.20). CONCLUSIONS: External compression dressing fails to decrease postoperative drainage and may increase the incidence of seroma formation after drain removal. Thus, routine use of a compression dressing to reduce postoperative drainage after ALND for breast cancer is not warranted.

Axilla↗
PubMed1987

The Blalock-Taussig shunt in infants: standard versus modified.

In recent years, the modified Blalock-Taussig shunt--a polytetrafluoroethylene graft from the subclavian artery to the pulmonary artery--has been preferred over the standard shunt by some surgeons because (1) it requires less dissection and (2) length of native vessels is not critical. From January, 1979, to June, 1985, we operated on 51 infants less than 1 year of age, including 26 less than 1 week of age, to palliate severe complex cyanotic congenital cardiac malformations. Twenty-four modified Blalock-Taussig shunts and 29 standard Blalock-Taussig shunts were created. The groups were concurrent. We reviewed all available cineangiograms and measured branch pulmonary and subclavian arteries. Pulmonary artery index was not different preoperatively in patients given a modified versus a standard Blalock-Taussig shunt (144 +/- 118 and 118 +/- 59 mm2/m2, respectively), but it was greater postoperatively in patients with a modified shunt (431 +/- 188 and 189 +/- 106 mm2/m2) (p = 0.07). Distortion of the pulmonary artery occurred less often after a modified Blalock-Taussig shunt (4/11) than a standard Blalock-Taussig shunt (6/8) (p = 0.06), though none of the distortions was severe. Early and late shunt failure occurred less often with a modified shunt (5/24) than with a standard shunt (15/29) (p less than 0.05). The modified Blalock-Taussig shunt had advantages over the standard Blalock-Taussig shunt in our series: pulmonary artery growth was greater, distortion of pulmonary arteries was less commonly seen, and shunt failure occurred less often. Thus, in infants, we believe the modified Blalock-Taussig shunt should be considered a reasonable alternative to the standard Blalock-Taussig shunt.

Blood Vessel Prosthesis↗
PubMed1980

Comparison of standardization techniques for manual colorimetric analyses.

The influence of both the mode of standardization and the type of standard on the precision of four manual colorimetric methods performed under optimal conditions variance is described. The terms variable calibration mode and constant calibration mode are proposed; these describe standardization by within-run standards and standardization by a predetermined calibration relationship between concentration and absorbance that remains constant over a fixed period of time. We show that calibration relationships and mode of standardization must be established for each and every individual method on objective evidence. Where within-run standards are used, they must be carefully selected for each method. The implications for method evaluation and quality control are discussed.

Blood Glucose↗
PubMed2001

Transvaginal hydrolaparoscopy but not standard laparoscopy reveals subtle endometriotic adhesions of the ovary.

OBJECTIVE: To determine whether transvaginal hydrolaparoscopy is superior to standard laparoscopy for detection of subtle endometriotic adhesions of the ovary. DESIGN: Videotapes of standard laparoscopy and transvaginal hydrolaparoscopy were viewed by an independent observer in random order and in a blinded manner. SETTING: Tertiary referral centers for infertility. PATIENT(S): Patients with minimal or mild endometriosis (n = 11) and unexplained infertility (n = 10) on standard laparoscopy from a group of 43 patients with infertility who were undergoing both studies. INTERVENTION(S): Transvaginal hydrolaparoscopy followed by standard laparoscopy. MAIN OUTCOME MEASURE(S): Detection of unexplained ovarian adhesions. RESULT(S): Patients with minimal and mild endometriosis and unexplained infertility had significantly more ovarian adhesions on transvaginal hydrolaparoscopy than on standard laparoscopy. The subtle adhesions seen on transvaginal hydrolaparoscopy but not on standard laparoscopy were filmy, microvascularized, and nonconnecting. CONCLUSION(S): Unexplained ovarian adhesions are frequently detected on transvaginal hydrolaparoscopy but not on standard laparoscopy in infertile patients with minimal and mild endometriosis and unexplained infertility.

Endometriosis↗
PubMed2003

A prospective trial of variable stiffness pediatric vs. standard instrument colonoscopy.

BACKGROUND: The pediatric variable stiffness colonoscope is believed to have theoretical advantages over the standard colonoscope, however a systematic evaluation of this instrument in routine clinical practice involving adult patients is lacking. METHODS: Consecutive patients (blinded) undergoing colonoscopy in an outpatient endoscopy center by one of 4 experienced colonoscopists had the procedure performed with a standard colonoscope (n=384) or pediatric variable stiffness colonoscope (n=413). Failure to negotiate the sigmoid colon within 10 minutes was regarded as a failure and, if suitable, the patient was crossed over to colonoscopy with the alternative instrument. RESULTS: Median (95% CI) time to the cecum was significantly faster in the pediatric variable stiffness colonoscope group (odds ratio 5.0: 95% CI[4.7,5.3] minutes) compared with the standard colonoscope group (odds ratio 5.5: 95% CI[5.2,5.8] minutes, p=0.01). There were 22 failures overall (2.8%), 14 in the standard colonoscope group (3.6%) and 8 in the pediatric variable stiffness colonoscope group (1.9%; p=0.1). With regard to the 14 failures in the standard colonoscope group, colonoscopy was attempted with the pediatric variable stiffness colonoscope in 13 and completed successfully in 12 (92%). The pediatric variable stiffness colonoscope was superior in cases of severe stenosing diverticular disease; two of 27 examinations with the pediatric variable stiffness colonoscope were rated as failed vs. 12 of 18 with the standard colonoscope (p<0.001). CONCLUSIONS: Intubation time was faster with the pediatric variable stiffness colonoscope, but use of this instrument was not associated with a superior cecal intubation rate compared with the standard colonoscope. However, in patients with severe stenosing diverticular disease, the intubation rate with the pediatric variable stiffness colonoscope was superior.

Cecal Diseases↗
PubMed1999

Selective cannulation of the common bile duct: a prospective randomized trial comparing standard catheters with sphincterotomes.

BACKGROUND: Current recommendations for the use of standard catheters or sphincterotomes for the initial attempt at selective common bile duct cannulation have been made in the absence of prospective comparative data. METHODS: A prospective study was carried out in which patients were randomized to undergo cannulation with a standard catheter or a sphincterotome (standard or wire-guided). Multivariate models were constructed to determine significant independent predictors of the success rates of initial and selective cannulation and the number of attempts and time needed to achieve selective cannulation. RESULTS: Eighty-three successive patients were evaluated; 36 were excluded because they had undergone previous therapeutic endoscopic retrograde cholangiopancreatography (ERCP) or a Billroth II operation. Of the 47 patients (28 women, mean age 60.6 +/- 14.5 years), indications for ERCP included suspected bile duct stones in 41 patients, pancreatico-biliary malignancies in 4, and biliary leaks in 2. Eighteen patients were randomized to undergo selective common bile duct cannulation with standard catheter and 29 to standard/wire-guided sphincterotome. Initial common bile duct cannulation for the standard catheter and standard/wire-guided sphincterotome groups was successful in 12 (67% [95% CI: 41%, 87%]) and 28 (97% [95% CI: 82%, 100%]) patients, respectively (95% CI for the difference: -0.57 to -0.03, p = 0.009). Using intention to treat analysis, selective common bile duct cannulation was successful for standard catheter and standard/wire-guided sphincterotome patients in 17 (94% [95% CI: 73%, 99%]) and 28 (97% [95% CI: 82%, 100%]) cases, respectively (95% CI for the difference: -0.15 to +0.10, p > 0.05). The mean number of attempts required to achieve selective common bile duct cannulation were 12.4 +/- 6.0 and 2.8 +/- 3.1 (p = 0.0001). The mean time taken to achieve selective common bile duct cannulation was 13.5 +/- 6.14 and 3.1 +/- 5.1 minutes (p = 0.0001). Multivariate modeling revealed that the initial choice of catheter was the only significant independent predictor of the time taken and the number of attempts performed to achieve selective common bile duct cannulation (p = 0. 0001 for each model). CONCLUSION: The use of standard/wire-guided sphincterotome was superior to that of standard catheter for the initial attempt at cannulation of the common bile duct. The number of attempts required may bear clinical significance with regard to the development of post-ERCP pancreatitis and warrants further study.

Adult↗
PubMed2003

Immunogenicity of decellularized cryopreserved allografts in pediatric cardiac surgery: comparison with standard cryopreserved allografts.

BACKGROUND: Recognition of the immunogenicity of standard cryopreserved allografts has led to the development of new decellularized allografts (CryoValve SG; CryoLife, Inc, Kennesaw, Ga). This preliminary study examined the HLA antibody response to these decellularized allografts and compared it with the response to standard allograft material. METHODS: We prospectively measured the frequency of panel-reactive HLA class I (HLA-A, HLA-B, and HLA-C) and class II (HLA-DR/DQ) alloantibodies in 14 children (age 8.5 +/- 7.9 years) receiving decellularized, cryopreserved allografts, including 6 undergoing allograft patch insertion and 8 with a valved pulmonary allograft. We compared them with 20 historical control subjects (age 1.7 +/- 2.4 years) undergoing implantation of standard cryopreserved allografts, 8 with valves and 12 with allograft patch. All patients had panel-reactive antibody levels measured before and at 1, 3, and 12 months after the operation. HLA class I and class II panel-reactive antibody levels were determined with a sensitive flow cytometry technique. RESULTS: We found panel-reactive antibody levels in decellularized allografts to be elevated slightly from preoperative levels for both class I and class II antibodies at 1, 3, and 12 months (P >.05). The panel-reactive antibody level for both class I and class II antibodies were significantly lower for decellularized allografts as compared to standard allografts. Functionally, the allografts were similar with decellularized valved grafts showing a peak echo-determined systolic gradient of 13 +/- 15 mm Hg at 8 +/- 2.6 months postoperatively as compared to a gradient of 24 +/- 18 mm Hg measured 12 +/- 6 months postoperatively in standard allografts (P =.11). CONCLUSIONS: Decellularized grafts elicited significantly lower levels of class I and class II HLA antibody formation at 1, 3, and 12 months after implantation than did standard cryopreserved allografts. Early hemodynamic function of decellularized grafts was similar to that of standard cryopreserved allograft valves. Further experience is necessary to determine whether the reduced immunogenicity of decellularized allografts will truly allow tissue ingrowth and improved long-term durability in patients.

Adolescent↗
PubMed2003

Evaluating several sources of variability for standard and SWAP visual fields in glaucoma patients, suspects, and normals.

PURPOSE: To quantify factors affecting test-retest variability of threshold measurements over a series of 3 serial visual fields (VF). DESIGN: Prospective comparative observational study. PARTICIPANTS: Forty-one normals, 10 suspects and 35 stable glaucoma patients. METHODS: All subjects performed 3 standard and 3 short-wavelength automated perimetry (SWAP) VFs. At each VF location, severity (defined as age-corrected total deviation) and test-retest variability (TRV), defined as the standard deviation of 3 serial threshold values, were calculated. A multiple regression model (constructed separately for standard VF and SWAP) incorporated 13 factors: severity, location, eccentricity, study group, diagnosis, superior versus inferior hemifield, nasal versus temporal hemifield, one-versus-two thresholds, age, mean pupil size, pupil size variability, between-subject variation, and residual variation. MAIN OUTCOME MEASURES: Variability in threshold sensitivity VF values. RESULTS: Mean TRV (+/- standard deviation) for normal, suspect and glaucoma eyes, respectively, was: 1.28 +/- 0.87, 1.53 +/- 1.04 and 2.20 +/- 1.79 dB for standard VF, and 1.87 +/- 1.35, 1.86 +/- 1.24 and 2.68 +/- 1.85 dB for SWAP. The contribution of each factor to the model for standard VF and SWAP (SWAP in parentheses) were: severity 15.5% (6.9%); location 2.7% (4.1%); eccentricity 1.1% (0.64%); diagnosis 2.9% (5.9%); "superior versus inferior" hemifield 0.17% (1.7%); "nasal versus temporal" hemifield 0.06% (0.02%); one-versus-two thresholds 0.04% (0.16%); age 0.1% (0.06%); mean pupil size 0.59% (0.1%); pupil size variability 3.2% (2.8%); between-subject 8.0% (13.5%) and residual variation 61.0% (66.6%). Excluding between-subject and residual variation, the 11-factor model was able to account for less than one third of the variability seen in both standard VF and SWAP. CONCLUSIONS: Severity of defect and between subject variation exerted the largest effect on TRV. However, even if all 11 factors could be adjusted for, it would reduce the magnitude of TRV by only 30%. More work is needed to reduce the remaining variability inherent in psychophysical testing and to better understand the intrinsic physiological variability present both in healthy and diseased eyes. It is possible that a larger number of VFs used for the calculation of TRV might further reduce the magnitude of the remaining variability found in this study.

Adult↗
PubMed1999

Standard combination versus alternating chemotherapy in small cell lung cancer: a randomised clinical trial including 394 patients. 'Petites Cellules' Group.

PURPOSE: to compare standard and alternating administration of chemotherapy combinations in small cell lung cancer (SCLC) patients. MATERIAL AND METHODS: in a multicenter clinical trial, 394 previously untreated SCLC patients were randomised to receive, every 4 weeks, eight courses of either a standard regimen with CCNU, cyclophosphamide, adriamycin (CCA) and VP16 or an alternating regimen (CCA regimen alternating with cisplatin-vindesine-VP16). RESULTS: overall response rate was higher in the standard group (78%) than in the alternating group (64%) (P = 0.0001). Complete response rate was also higher in the standard group (32%) than in the alternating group (18%) (P = 0.004). The median survival in the overall SCLC population was 306 days in the standard group and 272 days in the alternating group (P = 0.08). In limited SCLC patients, median survival was higher in the standard group (421 days) than in the alternating group (328 days) (P = 0.01). Grade III/IV haematological toxicity was lower in patients in the alternating group (25 versus 47%) (P < 0.001). CONCLUSION: the standard regimen was better than the alternating regimen for patients with limited forms of SCLC. The alternating regimen, associated with better haematological safety and ensuring a fairly similar survival, may be considered in patients with extensive SCLC. Pleiomorphic resistance mechanisms to chemotherapy make it difficult to define a non-cross-resistant chemotherapy regimen.

Adult↗
PubMed1997

Utility of a standard allergen series alone in the evaluation of allergic contact dermatitis: a retrospective study of 732 patients.

BACKGROUND: Patch testing remains the standard for the diagnosis of allergic contact dermatitis. The validity and usefulness of a standard patch test allergen series has not been addressed adequately by previous studies. OBJECTIVE: We sought to examine the utility of the standard allergen series as a sole screening tool in the diagnosis of allergic contact dermatitis. METHODS: The charts of 732 patients referred for patch testing were reviewed for positive patch test results. The group of patients with positive reactions was stratified into two groups based on the clinical relevance of their reactions. These groups were subsequently analyzed to determine whether the reactions were to part of the standard series of allergens or to part of a supplementary group. RESULTS: Of patients tested, 50% had a positive patch test. Of those, 221 (30%) had reactions deemed clinically relevant. Only 23% of patients with positive patch tests reacted to an allergen(s) in the standard series exclusively. When adjusted for clinical relevance, only 15.7% of patients were completely evaluated with the standard series of 20 allergens. CONCLUSION: The standard allergen series of 20 allergens available in the United States is limited as a screening tool when used alone in the evaluation of patients with allergic contact dermatitis.

Allergens↗
PubMed2003

The institutional design of forest certification standards initiatives and its influence on the role of science: the case of forest genetic resources.

In the 1990s a wide array of non-governmental certification initiatives emerged as a way to promote the sustainable management of resources in sectors such as fisheries and forestry. In this paper, we examine two related questions about these initiatives: how does the institutional design of certification initiatives affect the way science is used in the development of certification standards and in whose interest is science employed? Using the empirical case of forest certification and the specific standards various initiatives have created to address the management of forest genetic resources, we show how structural aspects of decision-making processes affects the standards adopted and the rationalization for their appropriateness. Two basic models of decision-making-stakeholder participation and technical expertise-are discussed in relation to three certification initiatives active in North America-the Canadian Standards Association, the Sustainable Forestry Initiative and the Forest Stewardship Council. By examining the standards these initiatives set for the management of forest genetic resources, we illustrate how two dimensions of science-uncertainty and the logic of cause and effect-are used to rationalize cautious and rigid versus flexible and discretionary standards for the management of forest genetic resources. Our findings indicate that the design or structure of certification decision-making processes, and their embedded balance of authority, mediate the form of standards initiatives will justify on the basis of science.

Certification↗
PubMed1997

A quantitative assessment of standard vs. customized midline shield construction for invasive cervical carcinoma.

PURPOSE: An individualized midline shield (MLS) has been advocated for delivering homogeneous radiotherapy for patients with invasive cervical carcinoma. Yet, many radiation oncologists continue to employ a standard block. In the latter instance, any deviation of the cranial-caudal central axis of he tandem from the patient's midline could result in dose inhomogeneity to tumor. A retrospective review of a single university medical center's experience with constructing the MLS was initiated to determine the outcome of using a standard block vs. a customized block that conforms to the "Point A" isodose line. In addition, participating radiation oncologists associated with the Gynecologic Oncology Group (GOG) were polled to assess if there exists a consensus regarding midline block utilization in the management of cervical cancer patients which could be compared to the institutional study. METHODS AND MATERIALS: From January 1, 1990 through December 31, 1992, 32 patients with invasive cervical carcinoma who underwent low dose rate brachytherapy at a single institution were identified. Patients were grouped as having a standard block (18 cases), customized block (5 cases), or no block (9 cases). The "Point A" isodose distribution from the implant was superimposed onto the whole pelvic simulation film and quantitatively compared to the actual or a hypothetical standard block outlined on the same radiograph. In September of 1995, 56 member and affiliated institutions in the GOG were surveyed concerning their use of a MLS, and the results were tabulated in December of 1995. RESULTS: Approximately 72% of all cases (23 out of 32) at the single institution had tandem deviation ranging from 0-230 with a median of 50. This translated into a median percent overdosage to "Point A" Right of 15% and "Point A" Left of 12.5%. Although overall survival and incidence of chronic complications have not been affected by type of shielding, patient follow-up is limited with a median of 17.7 months (range: 4.2-58.9 months). Of the 56 surveyed radiation facilities in the GOG, 34 (61%) responded. One center was subsequently excluded as it performs only high dose rate brachytherapy. Of the evaluable respondents, 88% (29 out of 33) utilize a MLS in treating their patients with invasive cervical carcinoma. Of the latter group, 76% (22 out of 29), 21% (6 out of 29), and 3% (1 out of 29) employ a standard block, customized block, and a "step-wedge," respectively. For those using a standard block, 77% (17 out of 22) align the central cranial-caudal axis of the MLS along the corresponding midplane of the patient's pelvis on an anteroposterior radiograph rather than along the superior-inferior central axis of the tandem. CONCLUSIONS: This study suggests that the use of a standard midline shield could result in potential tumor dose inhomogeneity and should be avoided. A national survey of major academic centers further suggests that the majority of these facilities also utilize a rectangular central block that is not positioned with respect to possible tandem deviation. Further investigation concerning the techniques of midline shield construction should be considered.

Adult↗
PubMed1985

Legal consequences of standard setting for competitive athletes with cardiovascular abnormalities.

This paper addresses the issue of whether establishing consensus standards for the treatment of particular medical conditions increases a physician's exposure to legal liability. The conclusion reached is that the legal effects of standard setting, rather than representing a significant threat of liability, should be seen as beneficial to the medical profession. A fundamental point is that the legal test for liability is entirely dependent on the medical profession's definition of what constitutes adequate care. The law incorporates the standard of care defined by the medical profession and does not impose an external norm. In the absence of formally stated standards, the process of defining relevant medical criteria will involve a great deal of uncertainty. Outcomes of legal contests will be affected by such extraneous factors as the relative experience of the lawyers involved, their access to knowledgeable expert witnesses, and their strategic decisions made with respect to tactics and procedures. Establishment of formal standards has the salutory effect of limiting the influence of these factors and thus reducing the randomness of the results reached. Formal standards also have the advantage of being easily replicated in unrelated proceedings and thereby contribute to the development of a consistent, evenly applied rule of liability. Finally, even if formal standards are either more, or less, progressive than the actual state of medical practice, there is relatively little risk that they will produce untoward results.

Heart Diseases↗