Biomedical subjects

A Asberg

Publications and source records attributed to A Asberg.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Diagnosis of depleted iron stores--do not use s-iron].

BACKGROUND: Analysis of s-ferritin is recommended for the diagnosis of depleted iron stores, but other parameters are still in use. The objective of this study was to determine the accuracy for s-iron, s-transferrin, transferrin saturation, b-hemoglobin and erythrocyte-MCH in diagnosing depleted iron stores. MATERIAL AND METHODS: Data was collected from the Health Study of Nord-Trøndelag, 1995-1997. Blood samples from 3029 women aged 20-45 were analysed for iron status. In absence of bone marrow aspirate, s-ferritin was used as the standard for iron deficiency. RESULTS: Highest diagnostic accuracy was found for s-transferrin. S-iron did not contribute with significant independent information. INTERPRETATION: S-iron should not be used in the diagnosis of depleted iron stores.

Adult↗

PubMed2000

Each administration of cyclosporin A enhances skin microvascular reactivity in renal transplant recipients.

Both impaired and enhanced microvascular function have been described in humans on cyclosporin A (CsA) therapy. In the present study we investigated the acute microvascular effects of a single CsA administration in renal transplant recipients on maintenance CsA therapy. Fourteen renal transplant recipients, median age 48 years (range 24-63 years), transplanted 4-12 weeks earlier, were included in this placebo-controlled, double-blinded, crossover study. All recipients had stable renal function; median serum creatinine was 116 micromol/L (range 80-184 micromol/L). Immunosuppressive therapy consisted of CsA, prednisolone, and either azathioprine or mycophenolate. Microvascular function was assessed by laser Doppler flowmetry in combination with acetylcholine (endothelium dependent) stimulation and the postocclusive reactive hyperemia test. Measurements were performed before (control) and 2.5 h following administration of CsA (Neoral) or matching placebo and repeated with reversed medication after at least 6 days. Vasodilative responses to acetylcholine stimulation were significantly higher following CsA ingestion compared with placebo. The mean change in AUC(1.5) (area under the flux versus time curve) from control to 2.5 h was 100 +/-145 for CsA and -292 +/- 140 AU x min for placebo (P = 0.047, n = 10). The postocclusive hyperemic response AUC(rh) was also significantly higher following CsA intake (39 +/- 4 AU x min) compared to placebo (30 +/- 4 AU x min) (P = 0.006, n = 12). This study shows that each dose of CsA induces a transient increase in skin microvascular reactivity in renal transplant recipients. We speculate that this might be due to the potentiation of one or several endothelial-dependent compensatory vasodilative mechanisms in the microvascular bed.

Adult↗

PubMed2000

CYP2D6 is involved in O-demethylation of diltiazem. An in vitro study with transfected human liver cells.

OBJECTIVE: In a previous study of diltiazem (DTZ) pharmacokinetics in renal transplant patients, we speculated that a polymorphic enzyme could be involved in O-demethylation of diltiazem. The aim of this in vitro study was to investigate whether O-demethylation of DTZ is mediated by cytochrome P450-2D6 (CYP2D6). METHODS: DTZ was incubated with transfected human liver epithelial (THLE) cells expressing CYP2D6 (T5-2D6 clone). Metabolism of DTZ was studied over a concentration range of 12.5-400 microM and in the presence of quinidine (a CYP2D6 inhibitor) or erythromycin (a CYP3A4 inhibitor). THLE cells lacking CYP2D6 activity (T5-neo clone) were used as control. The culture medium of the cells, in which DTZ was dissolved, was analysed for DTZ and metabolites prior to and after 8 h of incubation using high-performance liquid chromatography (HPLC, UV detection). Authentic O-demethyl-DTZ (Mx) was not available, and this metabolite was therefore not identifiable. RESULTS: Desacetyl-O-demethyl-DTZ (M4) was exclusively produced during incubations of DTZ with THLE cells expressing CYP2D6. The rate of M4 formation was described using Michaelis Menten kinetics in the concentration range of DTZ used. Production of M4 was inhibited by quinidine, but not erythromycin. An unidentified chromatographic peak, which was interpreted to be Mx, showed the same pattern of formation as M4 both in absence and presence of inhibitors. N-demethylated metabolites, formed by CYP3A4, were not observed in any of the cell lines. CONCLUSION: Evidence was provided in vitro that O-demethylation of DTZ is mediated by the polymorphic isoenzyme CYP2D6. Involvement of CYP2D6 in the metabolism of DTZ may have clinical implications regarding pharmacokinetic variability and interactions.

Acetylation↗

PubMed2000

5569G/A polymorphism of the HFE gene: no implications for C282Y genotyping in a hemochromatosis screening study of 65,238 individuals.

In a previous hemochromatosis screening study including a total of 65,238 individuals, 566 persons were genotyped for the C282Y and the H63D mutations. Of these, a total of 433 samples (298 homozygous C282Y and 135 homozygous wild type) were reanalyzed to investigate if the potential presence of the newly described 5569G/A polymorphism had confounded the genotyping results for the C282Y mutation. Genotyping with a polymorphism-insensitive primer pair yielded no samples that altered their genotype. By utilizing the polymorphism-sensitive primer pair and elevated annealing temperatures, 133 samples previously genotyped as heterozygous C282Y were reanalyzed to verify the presence of the polymorphism in the population studied. Out of a total of 266 chromosomes, we found the polymorphism present in 9 chromosomes, yielding an allele frequency of 0.034 in this particular subpopulation. In one of the samples, the polymorphism was present on the same DNA strand as the C282Y mutation. We conclude that in the population studied, the 5569 G/A polymorphism is present, but its presence had no implications for the outcome of the previous genotyping. Nevertheless, we recommend that C282Y genotyping by restriction endonuclease digestion of PCR products in the future should utilize a primer pair that is not influenced by the 5569G/A polymorphism.

Base Sequence↗

PubMed2000

Detection of an unusual combination of mutations in the HFE gene for hemochromatosis.

In the present paper, we describe an individual, found as part of a screening study, being homozygous for the C282Y mutation and at the same time heterozygous for the H63D mutation in the HFE gene. Identical results were obtained by three different methods, i.e., by PCR-RFLP, by sequencing, and by melting curve analysis. Thus, the common conception that the C282Y and the H63D mutations are mutually exclusive is not valid. Clinical symptoms and laboratory data on the individual were similar to hemochromatosis patients homozygous for the C282Y mutation. The implications of our finding for diagnostic analytical laboratory procedures are briefly discussed.

Adult↗

PubMed1999

Gene expression of the renal endothelin system in renal transplant recipients on cyclosporine A based immunosuppression.

BACKGROUND: Immunosuppressive therapy based on cyclosporine A (CsA) is potentially nephrotoxic, and each dose of CsA is followed by a transient increase in plasma endothelin (ET)-1. The aim of this study was to investigate the effect of CsA based immunosuppressive therapy on renal gene expression of the ET(A) and ET(B) receptor subtypes and preproET-1 in human transplant needle biopsies. METHODS: Twelve living donor renal transplant recipients, median age 51.5 years (range 24-63 years) were included in the study. Immunosuppressive therapy consisted of CsA, azathioprine, and prednisolone. Baseline renal cortical needle biopsies from the living donor kidneys were obtained just before nephrectomy. Follow-up biopsies were obtained from the same transplanted kidneys after 2-6 weeks of immunosuppressive therapy. We used a quantitative, competitive reverse transcriptase polymerase chain reaction assay to measure renal ET(A) and ET(B) receptor subtype mRNAs as well as preproET-1 mRNA levels in each of the biopsies. RESULTS: The renal ET system was not significantly altered by CsA-based immunosuppressive therapy. Median ET(A) mRNA level was 185 (range 35-244) at baseline, and 120 (11-189) amol/microg total RNA after CsA based immunosuppressive therapy (P=0.11). ET(B) mRNA level was 506 (209-1411) at baseline, and 463 (267-1609) amol/microg total RNA at follow-up (P=0.44) and preproET-1 mRNA level was 160 (112-392) before and 221 (187-361) amol/microg total RNA after immunosuppressive therapy based on CsA (P=0.58). CONCLUSION: This study indicates that 2-6 weeks of CsA-based immunosuppression neither significantly influences renal gene expression of the ET(A) or ET(B) receptor subtypes nor preproET-1 in living donor renal transplant kidneys.

Adult↗

PubMed1999

Nonspecific microvascular vasodilation during iontophoresis is attenuated by application of hyperosmolar saline.

Iontophoretic administration of acetylcholine chloride (ACh) and sodium nitroprusside (SNP) combined with laser Doppler skin blood perfusion measurements are used for determination of endothelial-dependent and -independent vasodilation. However, the method is biased by nonspecific vasodilation. The primary aim of this study was to investigate if iontophoresis-induced nonspecific vasodilation may be attenuated by addition of high molar concentrations of NaCl to the iontophoresis solutions. Secondary we investigated the applicability of 5 mol/liter NaCl solution as vehicle for ACh and SNP in this method. Skin perfusion changes were determined for iontophoresis of pure vehicles, deionized water and 5 mol/liter NaCl solution, in 12 healthy volunteers. Responses in skin perfusion to iontophoresis of ACh and SNP dissolved in both vehicles were also investigated. Addition of 5 mol/liter NaCl to deionized water significantly attenuated the nonspecific vasodilation and lowered the potential applied over the skin. The inter- and intraindividual coefficients of variation to ACh and SNP responses became, however, higher using hyperosmolar vehicle. During iontophoresis of SNP (in deionized water) we were unable to distinguish between SNP and vehicle effects. This study shows that the nonspecific vasodilation induced by iontophoresis can be attenuated by addition of 5 mol/liter NaCl, possibly due to lower electrical potential over the skin. However, the variability of the method was not improved. When deionized water was used as vehicle the effect of SNP could not be differentiated from that of the vehicle. This was not the case for ACh.

Acetylcholine↗

PubMed1999

Pharmacokinetic interactions between microemulsion formulated cyclosporine A and diltiazem in renal transplant recipients.

OBJECTIVE: Bilateral cyclosporin A (CsA) and diltiazem pharmacokinetic interactions have previously been investigated, however, not with the new microemulsion preconcentrate formulation of CsA (Sandimmun Neoral). In addition, the pharmacokinetic effects on the pharmacological active metabolites of diltiazem have not previously been investigated. We performed a pharmacokinetic interaction study in renal transplant recipients, measuring both unmetabolised CsA and diltiazem in addition to three of the main metabolites of diltiazem (MA, M1, M2). METHODS: Nine CsA-treated renal transplant patients were treated with diltiazem, 90-120 mg b.i.d., for 4 weeks. Pharmacokinetic investigations were performed both before and at the end of the diltiazem treatment period. Six non-CsA-treated renal transplant patients served as controls of CsA interactions with diltiazem and its metabolites. RESULTS: Diltiazem treatment resulted in a significant mean increase in the area under the concentration time curve (AUC) for CsA of 51(8)% (P < 0.008) and a peak concentration (Cmax) of 34(8)% (P < 0.05), without altering time to peak concentration (tmax). CsA, however, did not significantly influence diltiazem pharmacokinetics, though two of the metabolites (M1 and M2) tended to be increased. CONCLUSIONS: Diltiazem interacts significantly with the pharmacokinetics of CsA in the new microemulsion formulation. Microemulsion-formulated CsA, however, did not show significant interaction with diltiazem pharmacokinetics.

Adult↗

PubMed1999

A simple and sensitive high-performance liquid chromatography assay of diltiazem and main metabolites in renal transplanted patients.

A sensitive and specific reversed-phase high-performance liquid chromatographic method was developed for determination of the benzothiazepine calcium channel blocker diltiazem and three of its main metabolites in human plasma. A solid-phase extraction method (C18) is described for isolating diltiazem and the metabolites N-demethyl-diltiazem (M(A)), deacetyldiltiazem (M1) and N-demethyl-deacetyl-diltiazem (M2) from human plasma spiked with trans-diltiazem as internal standard. Chromatographic analysis of the eluate was accomplished using a reversed-phase column (C8) and a mobile phase consisting of acetonitrile, potassium dihydrogen phosphate-buffer (pH 2.9), triethylamine and methanol (280:598:2:90 v/v/v/v). The limit of detection was 5 ng/ml for diltiazem and 2.5 ng/ml for the metabolites (UV detection). Recoveries were > 75% for all substances. Precision analysis indicated a coefficient of variation below 5% for both diltiazem and metabolites at plasma concentrations ranging from 30 to 120 ng/ml for diltiazem and from 15 to 60 ng/ml for the metabolites. The accuracy was < 3% for diltiazem at all concentrations investigated. Metabolites showed an accuracy of < 7% at higher concentrations, however at low concentration the accuracy was < 16%. A pilot study has been performed in order to study whether the method was applicable to patients and volunteers. Plasma samples from renal transplanted patients treated with cyclosporin A and healthy volunteers did not show any interference by cyclosporin A with the determination of diltiazem and metabolites.

Adult↗

PubMed1999

Quality of life after cerebrovascular stroke: a systematic study of patients' preferences for different functional outcomes.

OBJECTIVES: To elicit valid quality of life estimates and the highest acceptable treatment risk of different outcomes after stroke. This is a prerequisite for rational medical decision-making, especially when considering treatments like thrombolysis. SUBJECTS: Healthy people, non-stroke medical patients and stroke survivors aged 20-84 years (n = 158) INTERVENTIONS: Subjects were interviewed by a physician using three different methods ('standard gamble', 'time trade-off' and 'direct scaling') supported by an interactive computer program. MAIN OUTCOME MEASURES: We measured utility, a numerical value ranging from 0.00 (death) to 1.00 (perfect health), representing the strength of the patient's preference for an outcome. When using the standard gamble method, risk is also introduced into the measurement. RESULTS: People's preferences for stroke outcomes varied widely, and the estimates were influenced by assessment method. We found that previous stroke, marital status and age were the only independent variables influencing the utility given. Subjects in our population over the age of 45 were very comparable to the real population at risk for acute stroke regarding these three variables, and they assigned a median utility of 0.91 (10th percentile, 0.65; 90th percentile, 0.99) to a minor stroke and 0.61 (10th percentile, 0.08; 90th percentile, 0.95) to a major stroke using the standard gamble method. CONCLUSIONS: Most people do not feel that suffering from stroke is an overwhelming catastrophe and they do not accept treatment options with very high risks.

Adult↗

PubMed1999

A decision analysis of thrombolytic therapy compared with standard therapy in acute ischaemic stroke.

OBJECTIVES: Experts draw different conclusions on whether thrombolysis can be recommended or not for acute ischaemic stroke. A major problem is weighing the improvement in functional ability against the risk of increased mortality. We wanted to examine this uncertainty regarding thrombolysis using a systematic approach and with a strong emphasis on the patient's point of view. METHODS: We performed a decision analysis where the base case focused on an average stroke patient. We used published probabilities for different functional outcomes after standard supportive care and after adding tissue plasminogen activator (tPA), and we tried to estimate corresponding long-term survival. We interviewed 158 subjects with the standard gamble method to elicit their preference values (utility) for these outcomes. RESULTS: When using the baseline data for an average stroke patient, thrombolysis with tPA was the better choice, with 48 extra quality-adjusted living days; tPA was also superior in 117 individual decision analyses, giving from 10 to 173 extra days. However, sensitivity analysis showed that these results were highly susceptible to changes in utility for major disability, probability of early death, and long-term survival after thrombolysis. To increase the gain as well as the margin of safety regarding the treatment choice, thrombolysis should be restricted to patients who assign low utility values < 0.6-0.7 to major poststroke disability (death = 0.0, good health = 1.0). CONCLUSION: Evaluated by decision analysis, thrombolysis with tPA is on average superior to standard therapy for the few patients fulfilling the strict medical inclusion criteria. Individual incorporation of the patient's point of view narrows the indication even further.

Acute Disease↗

PubMed1998

Quantification of mRNA levels of endothelin receptor subtypes and preproEndothelin-1 in renal needle biopsies by competitive reverse transcriptase polymerase chain reaction.

The vasoconstrictive peptide endothelin-1 (ET-1) is an autocrine/paracrine peptide of putative pathophysiological importance in renal transplant medicine. The aim of the present study was to develop a method for analysis of gene expression of the renal endothelin system in humans. Only small amounts of tissue are available from renal cortical needle biopsies. Thus, in the present study we developed a quantitative assay based on the competitive reverse transcriptase polymerase chain reaction (RT-PCR) technology. We quantified endothelin A (ET(A)) and B (ET(B)) receptor subtype mRNAs and preproET-1 mRNA levels in renal cortex biopsies obtained before nephrectomy of healthy kidney donors. Mean (+/- SEM) mRNA levels of the ET(A) and ET(B) receptor subtypes in 26 living donors were 212 +/- 23 and 368 +/- 56 amol/microg total RNA, respectively. The preproET-1 mRNA level in 19 living donors was 213 +/- 28 amol/microg total RNA. The inter-assay coefficient of variation (CV) for the assay was 10%; the intra-assay CV was 6-13%. The competitive RT-PCR assay described provides an accurate tool for gene expression investigation of the human endothelin system in renal cortical needle biopsies.

Adult↗

PubMed1998

Pulmonary hemodynamics and plasma endothelin-1 during hypoxemia and reoxygenation with room air or 100% oxygen in a piglet model.

The immediate effect on the pulmonary circulation of reoxygenation with either room air or 100% O2 was studied in newborn piglets. Hypoxemia was induced by ventilation with 8% O2 until base excess was <-20 mmol/L or mean arterial blood pressure was <20 mm Hg. Reoxygenation was performed with either room air (n = 9) or 100% O2 (n = 9). Mean pulmonary artery pressure increased during hypoxemia (p = 0.012). After 5 min of reoxygenation, pulmonary artery pressure increased further from 24 +/- 2 mm Hg at the end of hypoxemia to 35 +/- 3 mm Hg (p = 0.0077 versus baseline) in the room air group and from 27 +/- 3 mm Hg at the end of hypoxemia to 30 +/- 2 mm Hg (p = 0.011 versus baseline) in the O2 group (NS between groups). Pulmonary vascular resistance index increased (p = 0.0005) during hypoxemia. During early reoxygenation pulmonary vascular resistance index decreased rapidly to values comparable to baseline within 5 min of reoxygenation in both groups (NS between groups). Plasma endothelin-1 (ET-1) decreased during hypoxemia from 1.5 +/- 0.1 ng/L at baseline to 1.2 +/- 0.1 ng/L at the end of hypoxemia (p = 0.003). After 30 min of reoxygenation plasma ET-1 increased to 1.8 +/- 0.3 and 1.5 +/- 0.2 ng/L in the room air and O2 groups, respectively (p = 0.0077 in each group versus end hypoxemia; NS between groups). We conclude that hypoxemic pulmonary hypertension and plasma ET-1 normalizes as quickly when reoxygenation is performed with room air as with 100% O2 in this hypoxia model with newborn piglets.

Acid-Base Equilibrium↗

PubMed1998

Diltiazem modulates cyclosporin A induced renal hemodynamic effects but not its effect on plasma endothelin-1.

Cyclosporin A (CsA) has been reported to induce major acute renal hypoperfusion that may be antagonised by calcium channel blockers. The vasoconstrictive peptide endothelin-1 (ET-1) has been proposed as a mediator of CsA induced hypoperfusion. We investigated the acute effects of the new CsA formulation (Sandimmun Neoral) in 8 renal transplant patients on triple immunosuppressive therapy before and following slow-release diltiazem treatment in a dose of 90-120 mg b.i.d for 4 weeks. CsA significantly increased mean arterial blood pressure by 6 +/- 2 mmHg (p < 0.05) during the first 3 h after administration. This effect was abolished by diltiazem treatment, also reducing blood pressure by 12 +/- 3 mmHg (p < 0.05) 3-9 h after administration. CsA administration induced a maximum reduction in renal blood flow of 20 +/- 8% (p < 0.05) 5 h after ingestion and a concomitant reduction in glomerular filtration rate of 18 +/- 7% (p < 0.05). The filtration fraction increased by a maximum of 13 +/- 7% (p < 0.05) after 4 h as did the calculated fractional proximal reabsorption by 14 +/- 4% (p < 0.05). All these acute renal effects were abolished by diltiazem administration. Concurrent with the maximum renal hemodynamic effects, plasma ET-1 was elevated with a peak increase of about 40% 4-5 h after CsA ingestion. Diltiazem treatment had no effect on the increase in plasma ET-1 following CsA administration. These findings suggest that CsA induced acute vasoconstriction and renal hypoperfusion are mediated by ET-1 and that diltiazem treatment abolishes these pharmacodynamic effects of CsA despite persistent increase of plasma ET-1 levels.

Adult↗

PubMed1998

Glipizide treatment of post-transplant diabetes does not interfere with cyclosporine pharmacokinetics in renal allograft recipients.

BACKGROUND: Glipizide is an oral antidiabetic drug that has been used in the treatment of post-transplant diabetes mellitus (PTDM). However, a published case report has indicated a possible interaction of glipizide with cyclosporine (CsA) pharmacokinetics in two renal transplant (tx) patients. The aim of this open prospective study was to investigate whether glipizide interacts with CsA pharmacokinetics in renal tx patients with PTDM. METHODS: Eleven renal tx patients (29-74 years of age) with PTDM who received Sandimmun Neoral as part of their immunosuppressive therapy were investigated. No patients had suffered any significant rise in serum creatinine (20%) from any cause over the last 2 wk before the study. Mean S-creatinine was 137 mumol/L (87-220). The mean CsA dose and whole blood concentration remained unchanged during the study. CsA whole blood concentrations were monitored over 12 h in all patients in random order, both on and off glipizide treatment. Blood samples were drawn immediately before the morning dose of CsA was given (trough) and 0.5, 1, 1.5, 2, 3, 4, 6 and 12 h after administration. RESULTS: Whole blood trough CsA concentration was not altered by glipizide treatment, 256 +/- 76 micrograms/L off and 242 +/- 73 micrograms/L (mean +/- SD) with glipizide coadministration. The area under the curve (AUC) and terminal half-life of CsA remained unchanged with glipizide treatment: 6391 +/- 1483 micrograms/L per h and 7.3 +/- 1.5 h without; and 6279 +/- 1601 micrograms/L per h and 7.1 +/- 1.8 h with glipizide, respectively. No change in the CsA peak concentration (Cmax) was observed: 1507 +/- 406 micrograms/L without and 1469 +/- 538 micrograms/L with glipizide coadministration. CONCLUSION: CsA pharmacokinetics is not significantly altered by glipizide coadministration.

Adult↗

PubMed1997

Use and usefulness of laboratory handbooks.

The aim of this study was to investigate how reference handbooks distributed by hospital laboratories are used by medical doctors, and to what extent this kind of information can influence or change doctors' work habits. We also wanted to see if books with various contents of information are valued differently by the users, and we asked for preferences for an ideal book. A questionnaire was sent to 2075 medical doctors served by five Norwegian hospital laboratories. The overall response rate was 66%, of whom 76% had received a handbook. Seventy-eight percent of respondents who stated that they had received a handbook kept it in their consulting room and 45% used it once or more weekly. The majority (89%) found the books beneficial in their everyday work. Many doctors (36%) claimed that they had changed their routines as a result of the information in the book. The way of interpreting test results was influenced most often, followed by indications for ordering laboratory tests, sample collection and specimen handling, and patient preparation. Nearly all respondents (97%) felt that handbooks of this kind are beneficial to their technical and nursing staff. The results show that handbooks distributed by medical laboratories are well received, frequently used and highly appreciated by medical doctors. Comprehensive books are rated higher than smaller books.

Education, Medical, Continuing↗

PubMed1997

The accuracy of C-reactive protein in diagnosing acute appendicitis--a meta-analysis.

The aim of the study was to review the literature on the accuracy of C-reactive protein (CRP) in diagnosing acute appendicitis. All the relevant articles found by searching Medline and the Science Citation Index were reviewed. We used summary receiver operating characteristic (SROC) curve analysis to describe the central tendency of the studies and to assess potential sources of variability. We included 22 articles with a total number of 3436 patients. The sensitivity ranged from 0.40 to 0.99, and the specificity from 0.27 to 0.90. The cut-off values for a positive test varied from 5 to 25 mg l-1. SROC curve analysis showed that CRP performed significantly better in acute abdomen populations (11 studies) than in populations already selected for appendectomy (11 studies). The diagnostic accuracy of CRP tended to be a little inferior to that of total leukocyte count (13 studies). CRP is a test of medium accuracy in diagnosing acute appendicitis. The formerly distractingly wide range of sensitivity and specificity is at least partly due to variations in cut-off values and to differences in study populations. However, definitive conclusions on the clinical usefulness of the test could not be drawn.

Acute Disease↗

PubMed1997

Estimating the probability of acute appendicitis using clinical criteria of a structured record sheet: the physician against the computer.

OBJECTIVE: To evaluate physicians' probability estimates of acute appendicitis based on structured collection of clinical data. DESIGN: Open prospective study. SETTING: District hospital, Norway. SUBJECTS: 304 patients admitted with suspected acute appendicitis. INTERVENTIONS: Initial diagnostic accuracy of physicians was compared with corresponding results from a computer model. MAIN OUTCOME MEASURES: The estimated probabilities of appendicitis in different testing groups were analysed using receiver operating characteristic (ROC) curves. RESULTS: Physicians' estimates had a mean area under ROC-curve of 0.81 (95% CI 0.79 to 0.82), not significantly different from the computer model. Both correlated well with the actual rate of appendicitis, but the physicians tended to overestimate the probability by 10%. CONCLUSION: Physicians' probability estimates perform rather well. Further attempts to implement a probabilistic approach in the diagnostic process of acute appendicitis therefore seem justified.

Acute Disease↗