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Johann Steurer

Publications and source records attributed to Johann Steurer.

At least 19 recordsLinked to original sources
PubMed2007

Barriers to apply cardiovascular prediction rules in primary care: a postal survey.

BACKGROUND: Although cardiovascular prediction rules are recommended by guidelines to evaluate global cardiovascular risk for primary prevention, they are rarely used in primary care. Little is known about barriers for application. The objective of this study was to evaluate barriers impeding the application of cardiovascular prediction rules in primary prevention. METHODS: We performed a postal survey among general physicians in two Swiss Cantons by a purpose designed questionnaire. RESULTS: 356 of 772 dispatched questionnaires were returned (response rate 49.3%). About three quarters (74%) of general physicians rarely or never use cardiovascular prediction rules. Most often stated barriers to apply prediction rules among rarely- or never-users are doubts concerning over-simplification of risk assessment using these instruments (58%) and potential risk of (medical) over-treatment (54%). 57% report that the numerical information resulting from prediction rules is often not helpful for decision-making in practice. CONCLUSION: If regular application of cardiovascular prediction rules in primary care is in demand additional interventions are needed to increase acceptance of these tools for patient management among general physicians.

Attitude of Health Personnel↗
PubMed2006

Oral purified bacterial extracts in acute respiratory tract infections in childhood: a systematic quantitative review.

BACKGROUND: Recurrent acute respiratory tract infections (ARTI) are a common problem in childhood. Some evidence suggests a benefit regarding the prevention of ARTI in children treated with the immunomodulator OM-85 BV (Bronchovaxom). METHODS: We summarised the evidence on the effectiveness of the immunomodulator OM-85 BV in the prevention of ARTI in children. We searched randomised comparisons of oral purified bacterial extracts against inactive controls in children with respiratory tract diseases in nine electronic databases and reference lists of included studies. We extracted salient features of each study, calculated relative risks (RR) or weighted mean differences (WMD) and performed meta-analyses using random-effects models. RESULTS: Thirteen studies (2,721 patients) of low to moderate quality tested OM-85 BV. Patients and outcomes differed substantially, which impeded pooling results of more than two trials. Two studies (240 patients) reporting on the number of patients with less than three infections over 6 month of follow-up in children not in day care showed a trend for benefit RR 0.82 (95% CI, 0.65-1.02). One out of two studies examining the number of children not in day care without infections over 4-6 month reported a significant RR of 0.42 (95% CI, 0.21-0.82) whereas the smaller, second study did not [RR 0.92 (95% CI, 0.58-1.46)]. Two studies reporting the number of antibiotic courses indicated a benefit for the intervention arm [WMD 2.0 (95% CI, 1.7-2.3)]. Two out of the three studies showed a reduction of length of episodes of 4-6 days whereas a third study showed no difference between the two groups. CONCLUSION: Evidence in favour of OM-85 BV in the prevention of ARTI in children is weak. There is a trend for fewer and shorter infections and a reduction of antibiotic use.

Child↗
PubMed2006

More medical journals should inform their contributors about three key principles of graph construction.

OBJECTIVES: To identify key principles of graph construction and to review guidance on graph construction provided by medical journals. STUDY DESIGN AND SETTING: Review of a prevailing model of graph comprehension and survey of authors' instructions for all 120 core medical journals as indexed by PubMed. RESULTS: Graph construction should meet three requirements for optimal graph comprehension: Data symbols should be clearly distinguishable to enable their visual detection. Second, the data should be arranged in such a way that estimation of values and important relationships in the data is facilitated, and third, there should be a full explanation of all graph elements and of how the data were obtained. Seven journals (5.8%) provided recommendations on graph construction. Six journals put emphasis primarily on the explanation of graph elements and, to a lesser extent, on the visual detection of data symbols. Recommendations of the seventh journal focused mostly on how to enhance estimation of important relationships. All journals presented single recommendations whose selection seemed unstructured and not based on key principles of graph construction. CONCLUSION: Medical journals should order their instructions according to the three key aspects of graph construction.

Computer Graphics↗
PubMed2006

Predictors of intra- and postoperative complications in laparoscopic colorectal surgery: results of an expert survey.

BACKGROUND: The decision which patient should undergo laparoscopic rather than open colorectal surgery depends on weighing its benefits against its complications. We explored which criteria prognosticate complications in a laparoscopic intervention by assembling experienced visceral surgeons' beliefs. METHODS: A two-round postal survey was conducted: 21 experts in laparoscopic surgery were contacted and asked to list (first round) and weigh (second round) indicators (scale 1-10) they believed predicted intra- or postoperative complications in patients undergoing laparoscopic colorectal surgery. Median ratings and interquartile ranges (IQRs) were calculated. Rates >or=6 and IQRs <or=3 depicted an important prognostic indicator for complications. RESULTS: Thirty-nine intraoperative and 43 postoperative listings and ratings of 19 experts (90%) were available for analysis. The experts depicted three domains of indicators (tumor, comorbidity and related institution). The strongest indicators for intraoperative complications were surgeon's experience (median 9, IQR 8-10) and portal hypertension (median 9, IQR 7-10), and those for postoperative complications were liver cirrhosis Child B/C (median 8, IQR 7.75-10) and experience of the surgeon (median 8, IQR 7-10). CONCLUSION: This survey provides additional evidence of risk indicators for intra- and postoperative complications in patients undergoing laparoscopic colorectal surgery. Whether the identified indicators can be compiled into a prognostic instrument requires confirmation in a properly designed and sized study.

Colon↗
PubMed2006

Etiology in a taxonomy of illnesses.

According to what Robert Koch termed the etiological standpoint, illnesses are best understood and controlled by focusing on their causes, including in their definitions and, thus, in the construction of their taxonomies. In some ways flawed, this standpoint has been misunderstood and misapplied. A taxonomy based solely on etiology was an unrealistic dream in the context of 'the bacteriological revolution', and it also is unrealistic in the present context of 'the genetic revolution.' We argue that the illnesses in a taxonomy of them are in some cases best defined directly in terms of their respective somatic anomalies, in some others indirectly by the unique and universal etiology of that anomaly (left unspecified) in a 'deeper' somatic anomaly, and in yet others as a combination of these; and when the somatic anomaly for direct definition remains unknown, it is to be defined indirectly by the clinical syndrome that is its patient-relevant manifestation, possibly in conjunction with a somatic cause. We note, also, that these taxonomic issues have no material bearing on epidemiologists' etiologic research for the knowledge base of community-level preventive medicine.

Disease↗
PubMed2005

Does the Angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism modify the response to ACE inhibitor therapy?--A systematic review.

BACKGROUND: Pharmacogenetic testing to individualize ACE inhibitor therapy remains controversial. We conducted a systematic review to assess the effect modification of the insertion/deletion (I/D) polymorphism of the ACE gene on any outcome in patients treated with ACE inhibitors for cardiovascular and/or renal disease. METHODS: Our systematic review involved searching six electronic databases, then contacting the investigators (and pharmaceutical industry representatives) responsible for the creation of these databases. Two reviewers independently selected relevant randomized, placebo-controlled trials and abstracted from each study details on characteristics and quality. RESULTS: Eleven studies met our inclusion criteria. Despite repeated efforts to contact authors, only four of the eleven studies provided sufficient data to quantify the effect modification by genotypes. We observed a trend towards better response to ACE inhibitors in Caucasian DD carriers compared to II carriers, in terms of blood pressure, proteinuria, glomerular filtration rate, ACE activity and progression to end-stage renal failure. Pooling of the results was inappropriate, due to heterogeneity in ethnicity, clinical domains and outcomes. CONCLUSION: Lack of sufficient genetic data from the reviewed studies precluded drawing any convincing conclusions. Better reporting of genetic data are needed to confirm our preliminary observations concerning better response to ACE inhibitors among Caucasian DD carriers as compared to II carriers.

Journal Article↗
PubMed2005

A randomized trial of ways to describe test accuracy: the effect on physicians' post-test probability estimates.

BACKGROUND: Some people believe that likelihood ratios provide diagnostic information that is more useful than sensitivity and specificity estimates. OBJECTIVE: To assess how physicians' estimates about probability of illness are affected by the presentation of a diagnostic test's value as an estimate of sensitivity and specificity versus a likelihood ratio or an inexact numerical graphic. DESIGN: Random assignment of vignettes with different presentation formats of diagnostic test accuracy. SETTING: Auditorium at a continuing medical education conference. PARTICIPANTS: 183 physicians. INTERVENTION: After estimating probabilities of 6 common illnesses described in patient vignettes, physicians reviewed pertinent test results presented in 1 of 3 formats. MEASUREMENTS: Physicians' probability estimates of illness before and after receiving test information, and post-test probability estimates based on the Bayes theorem. RESULTS: Absolute percentage point differences between the physicians' estimated and the Bayes-based post-test probabilities varied from -7 to 31, from -7 to 28, and from 1 to 29 for the sensitivity and specificity, likelihood ratio, and graphical groups, respectively. Mean differences of probability estimates between the sensitivity and specificity and the likelihood ratio groups were small for all vignettes (-2 to 3 percentage points; summary mean z value across the 6 vignettes, 0.04 [95% CI, -0.14 to 0.21]). LIMITATIONS: The small pool of participants (who were potentially selected) and the limited number of vignettes prevented a more detailed analysis of relationships between the interpreted strength of diagnostic evidence and estimations of illness probability. CONCLUSIONS: These findings suggest that presenting diagnostic test accuracy with likelihood ratios does not affect some physicians' estimates of illness probability compared with presenting diagnostic test results as sensitivity and specificity.

Adult↗
PubMed2005

Respiratory rehabilitation after acute exacerbation of COPD may reduce risk for readmission and mortality -- a systematic review.

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (COPD) represent a major burden for patients and health care systems. Respiratory rehabilitation may improve prognosis in these patients by addressing relevant risk factors for exacerbations such as low exercise capacity. To study whether respiratory rehabilitation after acute exacerbation improves prognosis and health status compared to usual care, we quantified its effects using meta-analyses. METHODS: Systematic review of randomized controlled trials identified by searches in six electronic databases, contacts with experts, hand-searches of bibliographies of included studies and conference proceedings. We included randomized trials comparing the effect of respiratory rehabilitation and usual care on hospital admissions, health-related quality of life (HRQL), exercise capacity and mortality in COPD patients after acute exacerbation. Two reviewers independently selected relevant studies, extracted the data and evaluated the study quality. We pooled the results using fixed effects models where statistically significant heterogeneity (p < or = 0.1) was absent. RESULTS: We identified six trials including 230 patients. Respiratory rehabilitation reduced the risk for hospital admissions (pooled relative risk 0.26 [0.12-0.54]) and mortality (0.45 [0.22-0.91]). Weighted mean differences on the Chronic Respiratory Questionnaire were 1.37 (95% CI 1.13-1.61) for the fatigue domain, 1.36 (0.94-1.77) for emotional function and 1.88 (1.67-2.09) for mastery. Weighted mean differences for the St. Georges Respiratory Questionnaire total score, impacts and activities domains were -11.1 (95% CI -17.1 to -5.2), -17.1 (95% CI -23.6 to -10.7) and -9.9 (95% CI -18.0 to -1.7). In all trials, rehabilitation improved exercise capacity (64-215 meters in six-minute walk tests and weighted mean difference for shuttle walk test 81 meter, 95% CI 48-115). CONCLUSION: Evidence from six trials suggests that respiratory rehabilitation is effective in COPD patients after acute exacerbation. Larger trials, however, are needed to further investigate the role of respiratory rehabilitation after acute exacerbation and its potential to reduce costs caused by COPD.

Acute Disease↗
PubMed2005

Ultrasonography in screening for developmental dysplasia of the hip in newborns: systematic review.

OBJECTIVE: To assess the accuracy and effectiveness of the screening of all newborn infants for developmental dysplasia of the hip (DDH) using ultrasound imaging, as is standard practice in some European countries but not in the United Kingdom, the United States, or Scandinavia. DESIGN: Systematic review. DATA SOURCES: Twenty three medical, economic, and grey literature databases (to March 2004), with no limitations of design or language; some references were provided by experts. SELECTION OF STUDIES: Only diagnostic accuracy studies and comparative studies conducted in an unselected newborn population were eligible for the review. Two reviewers independently selected the studies and performed the quality assessment. RESULTS: The review identified one diagnostic accuracy study, and this was of limited quality. In this study the reference standard was treatment up to age of 8 months or an abnormal ultrasound finding at age 8 months. Ultrasound screening had a sensitivity of 88.5% (95% confidence interval 84.1% to 92.1%), specificity of 96.7% (96.4% to 97.4%), a positive predictive value of 61.6% and a negative predictive value of 99.4%. Ten studies evaluated the impact of ultrasound in screening, but these too had various methodological weaknesses, limiting the reliability of their findings. Compared with clinical screening, general ultrasound screening in newborns may increase overall treatment rates, but ultrasound screening seems to be associated with shorter and less intrusive treatment. CONCLUSIONS: Clear evidence is lacking either for or against general ultrasound screening of newborn infants for DDH. Studies that investigate the natural course of the disorder, the optimal treatment for DDH, and the best strategy for ultrasound screening are needed.

Clinical Trials as Topic↗
PubMed2005

Education and a standardized management protocol improve the assessment and management of asthma in the emergency department.

STUDY OBJECTIVE: To evaluate the effect of a standardized management protocol on acute asthma care in the emergency department (ED). METHOD: We conducted a before-after study regarding acute asthma management. Deficiencies in acute asthma care over a time period of 19 month (January 1997- October 1998) were identified. Subsequently a management protocol consisting of an assessment sheet and written guidelines for the initial management of acute asthma in the emergency department, was developed. In addition, physicians and nurses of the emergency department were informed about the recommendations given in the guidelines, and instructed in peak-flow meter use. The assessment sheet was introduced in January 2002 and posted at several locations in the emergency department. Between February 2002 and August 2003 the acute asthma consultations in the emergency department were consecutively registered. Data on medical history, physical examination and objective measurements of airflow obstruction, as well as data on treatment and assessment of the response to therapy were collected. In addition, medication and instructions at discharge were reviewed and compared with the results before the introduction of the assessment sheet. RESULTS: The first group consisted of patients seen between January 1997 and October 1998; the second group consisted of all patients seen between February 2002 and August 2003 (104 vs 273 patients respectively). Both groups had a similar gender distribution (56% females in the first group vs 53% females in the second group) and the mean age of both groups was also alike (median 33 vs 36 years). Most patients had a known history of asthma (76% in the first group vs 70% in the second group). The self-referral rate was high in both groups (86% vs 96% respectively). Blood pressure and pulse rate were reported in the majority of patients (95% vs 98% respectively), whereas the respiratory rates were reported in 14% of patients in the first group vs 65% of patients in the second group. The introduction of the assessment sheet led to an increased measurement of initial airflow obstruction (53% of patients in the first group vs 96% of patients in the second group) as well as repeated measures under treatment (36% of patients in the first group vs 85% of patients in the second group). Repeated inhalations with short-acting inhaled beta-agonists, and use of systemic corticosteroid therapy at admission and at discharge increased significantly (from 31% to 84%, 43% to 68% and 37% to 70% respectively). CONCLUSION: The assessment and management of patients presenting to the emergency department with acute asthma can be improved with a guideline based management protocol, and by educating physicians and nurses in the management of acute asthma.

Adult↗
PubMed2005

Posterior epistaxis: systematic review on the effectiveness of surgical therapies.

OBJECTIVE: The optimal surgical treatment for patients with posterior epistaxis and failed conservative therapy is unknown. Therefore we planned a systematic review studying all available publications assessing the effect on bleeding recurrence and postoperative complications of ligation of the internal maxillary artery or the sphenopalatine artery. METHODS: We searched the electronic databases Medline, Medline In Process, and Cochrane Library. Data extraction was performed following standard methods. RESULTS: Twenty-eight studies could be included in the systematic review. All studies were retrospective and no single study comparing different methods could be identified. Fifteen studies reported on the effect of the ligation of the internal maxillary artery (LIMA) and 13 on the effect of the ligation of the sphenopalatine artery (LSA). The severity of postoperative complications and duration of hospital stay seem to be lower in the LSA group. A conclusive statement about the frequency of rebleeding in the two groups is not possible. CONCLUSION: According to the available data on postoperative complications and duration of hospital stay ligation of the sphenopalatine artery compared favourably to the ligation of the internal maxillary artery. The most effective treatment for patients with posterior epistaxis including costs should be evaluated in a controlled clinical trial.

Epistaxis↗
PubMed2004

Comprehensive Geriatric Assessment (CGA) in general practice: results from a pilot study in Vorarlberg, Austria.

BACKGROUND: Most comprehensive geriatric assessment (CGA) programs refer to hospital-based settings. However the body of geriatric healthcare is provided by general practitioners in their office. Structured geriatric problem detection by means of assessment instruments is crucial for efficient geriatric care giving in the community. METHODS: We developed and pilot tested a German language geriatric assessment instrument adapted for general practice. Nine general practices in a rural region of Austria participated in this cross-sectional study and consecutively enrolled 115 persons aged over 75 years. The prevalence of specific geriatric problems was assessed, as well as the frequency of initiated procedures following positive and negative tests. Whether findings were new to the physician was studied exemplarily for the items visual and hearing impairment and depression. The acceptability was recorded by means of self-administered questionnaires. RESULTS: On average, each patient reported 6.4 of 14 possible geriatric problems and further consequences resulted in 43.7% (27.5% to 59.8%) of each problem. The items with either the highest prevalence and/or the highest number of initiated actions by the GPs were osteoporosis risk, urinary incontinence, decreased hearing acuity, missing pneumococcal vaccination and fall risk. Visual impairment was newly detected in only 18% whereas hearing impairment and depression was new to the physician in 74.1% and 76.5%, respectively.A substantial number of interventions were initiated not only following positive tests (43.7% per item; 95% CI 27.5% to 59.8%), but also as a consequence of negative test results (11.3% per item; 95% CI 1.7% to 20.9%). The mean time expenditure to accomplish the assessment was 31 minutes (SD 10 min). Patients (89%) and all physicians confirmed the CGA to provide new information in general on the patient's health status. All physicians judged the CGA to be feasible in everyday practice. CONCLUSION: This adapted CGA was feasible and well accepted in the general practice sample. High frequencies of geriatric problems were detected prompting high numbers of problem-solving initiatives. But a substantial number of actions of the physicians following negative tests point to the risks of too aggressive treatment of elderly patients with possibly subsequent negative effects.

Journal Article↗
PubMed2004

The accuracy of the Ottawa knee rule to rule out knee fractures: a systematic review.

BACKGROUND: The Ottawa knee rule is a clinical decision aid that helps rule out fractures and avoid unnecessary radiography. PURPOSE: To summarize evidence about the accuracy of the Ottawa knee rule. DATA SOURCES: Relevant English- and non-English-language articles were identified from PreMEDLINE and MEDLINE (1966-2003), EMBASE (1980-2003), CINAHL (1982-2003), BIOSIS (1990-2003), the Cochrane Library (2002, Issue 3), the Science Citation Index database, reference lists of included studies, and experts. STUDY SELECTION: Articles were included if they reported enough information to determine the sensitivity and specificity of the Ottawa knee rule for detecting fractures confirmed either radiologically or in combination with follow-up. DATA EXTRACTION: Two reviewers independently extracted data on study samples, the ways that the Ottawa knee rule was used, and methodologic characteristics of studies. DATA SYNTHESIS: Of 11 identified studies, 6 involving 4249 adult patients were considered appropriate for pooled analysis. The pooled negative likelihood ratio was 0.05 (95% CI, 0.02 to 0.23), the pooled sensitivity was 98.5% (CI, 93.2% to 100%), and the pooled specificity was 48.6% (CI, 43.4% to 51.0%). CONCLUSION: A negative result on an Ottawa knee rule test accurately excluded knee fractures after acute knee injury. However, because the rule is calibrated toward 100% sensitivity and actual fracture prevalences are usually low, large-scale, multicentered studies are still needed to establish the cost-effectiveness of routinely implementing the rule.

Decision Support Techniques↗
PubMed2004

Oral purified bacterial extracts in chronic bronchitis and COPD: systematic review.

BACKGROUND: Oral lyophilized extracts of bacteria species have been used since the early 1970s to improve symptoms and to prevent exacerbations in COPD patients. The value of these treatments, which are thought to be immunomodulating, is poorly understood. Our aim was to quantify the efficacy of oral bacteria extracts in patients with chronic bronchitis and COPD. DESIGN: Systematic review of randomized trials. DATA SOURCES: Electronic databases, bibliographies, and contact with authors and manufacturers. REVIEW METHODS: Randomized comparisons of oral purified bacterial (active) extracts with placebo or no treatment (control) were selected. Meta-analyses were performed using fixed and random-effects models, and the results were expressed as relative risk (RR), odds ratio (OR), number needed to treat for one to benefit (NNTB), or number needed to treat for one to be harmed (NNTH), with 95% confidence interval (CI). RESULTS: Thirteen trials (1,971 patients), most of which were of low quality, tested OM-85BV (Broncho-Vaxom; OM Pharma; Geneva, Switzerland), LW-50020 (Luivac; ALTANA Pharma; Bad Homburg, Germany), or SL-04. Two trials (731 patients) had appropriate methodologies and reported on exacerbations. The RR in favor of the oral bacterial extract (active) was 0.83 (95% CI, 0.55 to 1.25), and the NNTB was 15.4 (95% CI, 5.5 to infinity; NNTH, 27.5). Five trials (591 patients) reported on observer-assessed improvement of symptoms RR in favor of active extracts was 0.57 (95% CI, 0.49 to 0.66), and the NNTB was 4 (95% CI, 2.8 to 5.4). Two trials (n = 344), reported on patient-assessed improvement (RR, 0.44; 95% CI, 0.31 to 0.61) [NNTB, 4; 95% CI, 3.0 to 5.9]. In two trials (163 patients), the average duration of an exacerbation was shorter with the active extracts (weighted mean difference, -2.7 days; 95% CI, -3.5 to -1.8). Itching or cutaneous eruptions was reported in 3.3% of patients (four trials; 802 patients) who received active extracts compared with 1.0% of control subjects (OR, 2.94 95% CI, 1.12 to 7.69) [NNTH, 50; 95% CI, 14 to 161]. Urologic problems (two trials; 671 patients) were reported in 8% of patients who received active extracts compared with 3.0% of control subjects (OR, 2.62; 95% CI, 1.35 to 5.11) [NNTH, 22; 95% CI, 10 to 61]. CONCLUSIONS: Oral purified bacterial extracts improve symptoms in patients with chronic bronchitis and COPD. There is not enough evidence to suggest that they prevent exacerbations. Cutaneous and urologic adverse effects are common.

Administration, Oral↗
PubMed2003

Accuracy of Ottawa ankle rules to exclude fractures of the ankle and mid-foot: systematic review.

OBJECTIVE: To summarise the evidence on accuracy of the Ottawa ankle rules, a decision aid for excluding fractures of the ankle and mid-foot. DESIGN: Systematic review. DATA SOURCES: Electronic databases, reference lists of included studies, and experts. REVIEW METHODS: Data were extracted on the study population, the type of Ottawa ankle rules used, and methods. Sensitivities, but not specificities, were pooled using the bootstrap after inspection of the receiver operating characteristics plot. Negative likelihood ratios were pooled for several subgroups, correcting for four main methodological threats to validity. RESULTS: 32 studies met the inclusion criteria and 27 studies reporting on 15 581 patients were used for meta-analysis. The pooled negative likelihood ratios for the ankle and mid-foot were 0.08 (95% confidence interval 0.03 to 0.18) and 0.08 (0.03 to 0.20), respectively. The pooled negative likelihood ratio for both regions in children was 0.07 (0.03 to 0.18). Applying these ratios to a 15% prevalence of fracture gave a less than 1.4% probability of actual fracture in these subgroups. CONCLUSIONS: Evidence supports the Ottawa ankle rules as an accurate instrument for excluding fractures of the ankle and mid-foot. The instrument has a sensitivity of almost 100% and a modest specificity, and its use should reduce the number of unnecessary radiographs by 30-40%.

Ankle Injuries↗
PubMed2003

Assessment of clinical utility of 18F-FDG PET in patients with head and neck cancer: a probability analysis.

The purpose of this study was to calculate disease probabilities based on data of patients with head and neck cancer in the register of our institution and to perform a systematic review of the available data on the accuracy of PET in the primary assessment and follow-up of patients with head and neck cancer. The pre-test probability of head and neck cancer among patients in our institutional data registry was assessed. Then the published literature was selected and appraised according to a standard protocol of systematic reviews. Two reviewers independently selected and extracted data on study characteristics, quality and accuracy. Accuracy data were used to form 2 x 2 contingency tables and were pooled to produce summary receiver operating characteristic (ROC) curves and summary likelihood ratios for positive and negative testing. Finally post-test probabilities were calculated on the basis of the pre-test probabilities of this patient group. All patients had cytologically or histologically proven cancer. The prevalence of additional lymph node metastases on PET in staging examinations was 19.6% (11/56), and that of locoregional recurrence on restaging PET was 28.6% (12/42). In the primary assessment of patients, PET had positive and negative likelihood ratios of 3.9 (2.56-5.93) and 0.24 (0.14-0.41), respectively. Disease probabilities were therefore 49.4% for a positive test result and 5.7% for a negative test result. In the assessment of recurrence these values were 3.96 (2.8-5.6) and 0.16 (0.1-0.25), resulting in probabilities of 49.7% and 3.8%. PET evaluation for involvement of lymph nodes had positive and negative likelihood ratios of 17.26 (10.9-27.3) and 0.19 (0.13-0.27) for primary assessment and 11.0 (2.93-41.24) and 0.14 (0.01-1.88) for detection of recurrence. The probabilities were 81.2% and 4.5% for primary assessment and 73.3% and 3.4% for assessment of recurrence. It is concluded that in this clinical setting the main advantage of PET is the ability to reliably rule out the presence of disease in both staging and restaging. Further research is required to derive probabilities for individual patients from sequential testing as applied in the diagnostic work-up of patients with head and neck cancer.

Adult↗