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C van de Beek

Publications and source records attributed to C van de Beek.

8 recordsLinked to original sources
PubMed1999

[Appropriate treatment of benign prostatic hyperplasia; refining the indications for treatment by systematic analysis of expert opinion].

OBJECTIVE: To assess systematically the opinion of urology experts regarding the appropriateness of indications for treatment of benign prostatic hyperplasia (BPH) and to evaluate the potential use of these expert opinions for the refinement of treatment guidelines. DESIGN: Modified Delphi procedure. METHODS: A panel of 12 Dutch urologists judged the appropriateness of three common treatments (surgery, alpha-adrenergic antagonists, finasteride) for 1152 hypothetical cases of BPH. These cases consisted of all combinations of 9 diagnostic characteristics considered relevant to treatment choice. The study population was restricted to patients for whom current (evidence-based) guidelines do not provide clear indications on the most appropriate treatment. The panel members individually rated the appropriateness of the three active treatments using a 1 to 9 scale, each in comparison with 'watchful waiting'. By combining the results on agreement and appropriateness, aggregate panel judgements were calculated for each indication (appropriate, inappropriate, uncertain). The relationship between diagnostic characteristics and panel opinions was studied using logistic regression methods. RESULTS: For patients without previous treatment for BPH, surgery was considered appropriate in 44% of cases. For alpha-blocking drugs and finasteride, these values were 70% and 3% respectively. Logistic regression analysis revealed a strong and consistent relationship between the several diagnostic characteristics and the panel judgement 'appropriate indication'. CONCLUSION: Systematic analysis of clinical expertise can offer a meaningful contribution to the refinement of indications for BPH treatments.

Adrenergic alpha-Antagonists↗
PubMed1998

Utility of ultrasound of the upper urinary tract in elderly men with indicators of obstructive symptoms or abnormal flow: how often can silent hydronephrosis be detected in general practice?

BACKGROUND AND OBJECTIVE: While the prevalence of hydronephrosis is very low in obduction studies, a prevalence of 3-13% is reported for patients with an obstruction who are listed for prostatectomy. In order to evaluate the usefulness of transabdominal ultrasound in primary care, we determined the occurrence of hydronephrosis in males with symptoms of urinary obstruction in a general practice setting. METHOD: A micturition questionnaire (a modified Boyarsky) was sent to all men of 55 years or more who were registered in 10 general practices in Maastricht, and was followed by an examination at their general practice. Men with obstructive symptoms and/or with a free-flow abnormality were examined in the hospital with transabdominal ultrasound in order to detect dilatation of the upper urinary tract. This ultrasound was repeated approximately 15 months later. RESULTS: At the first measurement, none of the examined men (n = 178) had hydronephrosis, and this was still the case for 94 men 15 months later. CONCLUSION: Renal ultrasound is not necessary in general practice for men with uncomplicated obstructive complaints.

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PubMed1997

Combined hormono/chemotherapy as primary treatment for metastatic prostate cancer: a randomized, multicenter study of orchiectomy alone versus orchiectomy plus estramustine phosphate. The Dutch Estracyt Study Group.

OBJECTIVES: Based on the theory that hormone-resistant cells are present in all metastatic patients, early administration of chemotherapy appears to be logical and its use is supported by experimental studies. Therefore, trials with combined hormonal and cytotoxic treatment as primary therapy should be conducted. In the present trial, the efficacy and tolerance of estramustine phosphate (EMP) as a chemotherapeutic agent in addition to hormonal treatment (orchiectomy) was studied in patients with metastatic and nonmetastatic prostate cancer not previously treated. EMP was chosen because it produces few serious adverse reactions and no cumulative toxicity. METHODS: Four hundred nineteen patients were included in a 1.5-year period starting in January 1989. Patients with locally advanced prostate cancer or with bone metastases were randomized to orchiectomy (O) or orchiectomy followed by EMP (O + E), given until progression. RESULTS: Analysis of the total group showed no significant difference in time to progression between the treatment groups. Because the course of the disease is different in patients with either T4 tumor only or with lymph node metastases only (M0) as compared with patients with bone metastases (M1) and because the number of progressions in the M0 patients was low, corresponding analyses were performed for these subgroups as well. In the M1 patients, there was a tendency for a longer time to progression in the O + E group than in the O group, but there was no indication of a difference between the groups with regard to survival. In the M0 patients, there was no indication of any difference in results between the treatments. Multivariate analysis of prognostic factors showed pain, alkaline phosphatase, metastasis status, and tumor stage to be significant factors. There was a relation between age and drug treatment in that a significant beneficial effect of EMP in terms of prolonged progression-free interval as well as survival was evident in younger patients (aged less than 73 years) with metastatic disease. Tumor stage was also of importance for the drug effect; T0 to T3 patients who received EMP survived longer than those who were treated with orchiectomy only. The most common adverse reaction was nausea in the O + E group, which led to discontinuation of the drug in 7 patients. Cardiovascular problems are not uncommon in this age group, and there was a higher incidence of cardiovascular events, predominantly cardiac failure, in the O + E group, leading to treatment interruption in 16 patients. CONCLUSIONS: Our results indicate that future studies of hormono/chemotherapy should focus on younger patients with bone metastases.

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PubMed1996

[Variation in the diagnosis and treatment of benign prostatic hyperplasia in urological practice].

OBJECTIVE: To analyse practice variation among urologists and its determinants with respect to diagnostics and therapy choice in benign prostatic hyperplasia (BPH). DESIGN: Cross-sectional. SETTING: Stratified sample of 12 urological practices throughout the Netherlands. METHODS: On 670 consecutive, newly referred BPH patients > or = 50 years, data were collected about symptomatology, discomfort and sexual functioning (patient questionnaire), diagnostic procedures and outcomes (medical record), and (considerations for) therapy choice (urologist questionnaire). Characteristics of patients as well as of urologists were integrally studied to explain the variation. RESULTS: With respect to diagnostics, highest variation (interquartile ranges) was found for ultrasonography of the prostate (19-86%), kidneys (19-68%), and bladder (42-91%), and lowest variation for digital rectal examination (97-100%) and blood tests and urinalysis (88-100% and 86-99% respectively). For therapy choice, interquartile ranges were 24-42% (surgery), 32-49% (watchful waiting), 5-29% (alpha-blockers), and 0-17% (5-alpha-reductase-inhibitor). Variation in diagnostics was associated with characteristics of urologists and work setting as well as of patients. For differences in therapy choice, symptomatology, discomfort, sexual activity, peak flow, volume of residual urine, prostate volume, comorbidity, experience of the urologist, and the type of hospital were the most important explanatory variables. CONCLUSION: Variation in both diagnostics and therapy choice is considerable. This variation is associated with characteristics of patients as well as of urologists and work setting.

Adrenergic alpha-Antagonists↗
PubMed1996

The symptom questionnaire for benign prostatic hyperplasia: an ambiguous indicator for an ambiguous disease.

OBJECTIVE: To assess the criterion validity of the American Urological Association (AUA) symptom index for benign prostatic hyperplasia (BPH) in urological practice. PATIENTS AND METHODS: The study comprised 1414 consecutive men > or = 50 years of age, newly referred to a urologist in a stratified sample of 12 hospitals throughout the Netherlands, who completed the AUA symptom questionnaire at their first visit. The 39 urologists completed a questionnaire on the diagnosis. The discriminative power of the index for BPH versus other urological diagnoses was calculated by receiver operating characteristic (ROC) analysis. Subsequently, criterion sensibility was studied by assessing the effect of particular variables on the probability of the diagnosis of BPH. RESULTS: ROC areas were low for BPH versus prostate cancer (0.57, SE 0.04), chronic prostatitis/prostatodynia (0.65, SE 0.03), and other diseases of the lower urinary tract (0.57, SE 0.04). Satisfactory to good values were found for BPH versus diseases of the upper urinary tract (0.79, SE 0.03), impotence/infertility (0.79, SE 0.04), penile-scrotal diseases (0.85, SE 0.02), and no abnormalities (0.84, SE 0.03). The diagnosis of BPH, as made by urologists in daily practice, appeared to be a weak criterion. Irrespective of other characteristics, the chance of being diagnosed with BPH was affected by differences in definition and the type of hospital. CONCLUSION: Although the AUA index discriminated fairly well between BPH and diseases of the upper urinary tract, as well as genital diseases, it has no potential for distinguishing BPH from other diseases of the lower urinary tract. In addition, the lack of consensus in defining clinical BPH underscores the weakness of the index as a tool in the diagnostic process of this disease.

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