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R Bernsen

Publications and source records attributed to R Bernsen.

7 recordsLinked to original sources
PubMed2005

Validity of three calliper-based transrectal ultrasound methods and digital rectal examination in the estimation of prostate volume and its changes with age: the Krimpen study.

BACKGROUND: Prostate volume and its changes are important parameters in studies of the natural history of benign prostatic hyperplasia (BPH), for prediction of treatment effect and the risk of adverse outcomes. The validity of three calliper-based transrectal ultrasound (TRUS) methods and digital rectal examination (DRE) is compared to transrectal planimetric prostate ultrasonometry. METHODS: Data were collected from 1,688 population-based men aged 50-78 years. Measurements included DRE, TRUS using the planimetric method, and three different calliper-based TRUS methods for the estimation of prostate volume. After 2.1 and 4.2 years these measurements were repeated. The agreement between these methods and the ability to discriminate between prostates with volumes above or below a certain cut-off was analyzed. The performance of the different methods to measure changes in prostate volume with age was also studied. RESULTS: All three ultrasound-based methods showed good discrimination compared to the planimetric method. However, the agreement between planimetric volumetry and the other ultrasound methods and DRE is poor. In this study, 22.6% of the men had a real increase in prostate volume after 4.2 years, using the planimetric technique of transrectal ultrasonometry. Only a small percentage of the men (<1.5%) has a real decrease in prostate volume. The alternative measurement methods had a low predictive value for changes in prostate volume with age as measured with the planimetric method. CONCLUSIONS: Calliper-based ultrasonometry and DRE show poor agreement with planimetric volume measurement of the prostate. Changes in prostate volume as determined by the planimetric method are poorly detected by the alternative methods. (c) 2004 Wiley-Liss, Inc.

Aged↗
PubMed2000

Estimating treatment effects in randomized clinical trials in the presence of non-compliance.

In clinical trials where patients are randomized between two treatment arms, not all patients comply with the treatment they were randomly assigned to. The reasons for (non)compliance may be associated with the outcome variable and thereby act as confounders. The standard way of analysing such trials is by the 'intention-to-treat' principle, which allows the use of permutation tests. Conclusions drawn from such tests do not depend on untested assumptions such as absence of confounding. However, this approach may yield biased estimators for the causal effects of treatments. We consider the estimation of such effects for clinical trials where non-compliers can be considered to have switched to the other trial arm. The most important example of this is the placebo-controlled clinical trial where no substantial placebo effects are anticipated. We consider the situation where the relationship between compliance, and thus treatment received, and outcome is influenced by unobserved confounders. The residual of the regression of the actual treatment indicator variable on the randomization arm indicator variable is shown to 'intercept' the effect of such confounders. Inclusion of this residual in a multivariate analysis, in conjunction with the treatment indicator variable, should thus adjust for confounding. Examples are given. In those examples, the results are similar to those obtained by more complex methods.

Anticholesteremic Agents↗
PubMed2000

How do general practitioners manage hip problems in adults?

OBJECTIVE: To investigate the medical management, and its consistency and determinants, of hip problems in adult patients. SETTING: General practice, The Netherlands. DESIGN: Observational study based on four "paper patients" and on computerised patients records (CPRs) of 400 patients (20 per general practitioner), aged 50 years and over, with new hip problems. SUBJECTS: 20 general practitioners. MAIN OUTCOME MEASURES: Examination, diagnosis and treatment of hip patients. RESULTS: Medical history and physical examination consisted mainly of questions concerning pain localisation and onset, and examining passive hip motion. The paper patients, except for the one with alarming symptoms, and the CPRs showed high variation in management between general practitioners, particularly for medication prescription and X-ray requests. Main factors influencing medical management were patients' age, number of visits and attitude of the individual general practitioner. A specific diagnosis was registered for only 32% of the 400 patients. The diagnosis osteoarthritis varied greatly between general practitioners even after adjustment for patients' age, gender and number of visits. Patients with osteoarthritis were infrequently referred to physical therapy and received nonsteroidal anti-inflammatory drugs (NSAIDs) more often than paracetamol. CONCLUSION: Diagnosis and treatment of hip problems varies widely between general practitioners. Treatment of patients with osteoarthritis is inconsistent with published recommendations.

Aged↗
PubMed2000

Meralgia paresthetica is related to degenerative pubic symphysis.

OBJECTIVE: To investigate the relationship between meralgia paresthetica, a mononeuropathy of the lateral femoral cutaneous nerve that often starts in middle age, and radiological degeneration of the pubic symphysis. METHODS: A case-control study of patients aged 40 years and older with meralgia paresthetica who underwent surgical release of the lateral femoral cutaneous nerve; cases were included only when a pelvic radiograph was available. The control group was from a population study including persons aged 55 years and older and was matched to cases (4 controls per case) for sex and age as far as possible. We checked patient records from general practice to ensure control subjects had no symptoms of meralgia paresthetica during the previous 10 years. Radiological degeneration of the pubic symphysis was defined as present when 2 of 3 independent observers noted degeneration on the radiograph. RESULTS: Mantel-Haenszel procedure (stratified for age group and radiological osteoarthritis of the hip) showed a positive relationship (p = 0.004, OR = 4.38) between radiological degenerative pubic symphysis and meralgia paresthetica. In a separate analysis limited to men we also found this positive relationship. CONCLUSION: This study confirmed a positive relationship between radiological degeneration of the pubic symphysis and meralgia paresthetica.

Female↗
PubMed1986

Ipratropium bromide (Atrovent) as inhalation powder. A double-blind study of comparison with ipratropium as a pressure aerosol in patients with reversible airways obstruction.

The bronchospasmolytic effects of 40 micrograms ipratropium bromide (Atrovent) given either as an aerosol (2 puffs of 20 micrograms) or as a powder inhalation were compared in a double-blind cross-over study. Following a randomisation list the drug was given on 2 successive days to 20 patients with stable bronchospasm in whom it had previously been shown that the bronchial obstruction was reversible after administration of 40 micrograms ipratropium bromide as an aerosol (with an increase over the baseline value of the FEV1 of at least 15% 1 h after drug administration). The effects of the two presentations of ipratropium bromide were followed by respiratory function tests from 15 min to 6 h after administration of the drug. With both formulations excellent bronchospasmolytic effects were noted in each of the parameters measured. The peak of the effects was noted approximately 1 h after the inhalations. Six hours later there was still a significant improvement in comparison with the baseline values. There was no significant difference between the results with the two different formulations. Inhalation powder of ipratropium bromide was well tolerated and there were no complaints of irritation or coughing. It would appear, therefore, to be a valuable alternative to the pressure aerosol.

Administration, Intranasal↗
PubMed1984

Comparative study of the bronchospasmolytic effect of fenoterol (0.2 mg) salbutamol (0.4 mg) as powder inhalations in 20 patients with reversible bronchial obstruction.

In a double-blind crossover study, the effects of fenoterol powder inhaled from capsules (0.2 mg) and the powder inhaler with salbutamol capsules (0.4 mg) were compared. A single dose of each was administered on 2 subsequent days in random order. The effects on lung function test results were followed from 15 to 360 min after administration. Apart from the overall comparison, special attention was paid to the beginning and the end of the test periods. Statistically significant differences were found only in a few parameters and showed a trend for fenoterol to have a somewhat longer effect and for salbutamol to have a faster onset of effect. The differences between the effects of the two drugs were clinically not relevant. Blood pressure and heart rate were unaffected by either treatment.

Administration, Intranasal↗