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Biomedical subjects

J Kievit

Publications and source records attributed to J Kievit.

At least 19 recordsLinked to original sources
PubMed1998

Carotid recurrent stenosis and risk of ipsilateral stroke: a systematic review of the literature.

BACKGROUND: The main goal of follow-up after carotid endarterectomy is to prevent new strokes caused by recurrent stenosis. To determine the most cost-effective follow-up schedule, it is necessary to know the incidence of recurrent stenosis and the risk of stroke it carries. METHODS: A systematic review of the literature was performed using standard meta-analytical techniques. RESULTS: Incidence of recurrent stenosis: The data were very heterogeneous. The risk of recurrent stenosis was 10% in the first year, 3% in the second, and 2% in the third. Long-term risk of recurrent stenosis is about 1% per year. Risk of stroke: The reported relative risks of stroke in patients with recurrent stenosis compared with patients without recurrent stenosis showed extreme heterogeneity and ranged from 10 to 0.10. The random effects summary estimator of relative risk was 1.88. CONCLUSIONS: The data were very heterogeneous, and much better data are needed to arrive at truly reliable estimates of these important parameters of follow-up. It is clear, though, that the risk of recurrent stenosis is highest in the first few years after carotid endarterectomy and very low in later years. By use of general decision-analytic arguments, it can be argued that, given the test characteristics of carotid ultrasound, a small number of tests can be done in the first few years and that testing for restenosis should not be done after 4 years.

Aged↗
PubMed1997

[Financial limits to care; a survey among physicians].

OBJECTIVE: To determine physicians' opinions about the role of cost considerations in treatment decisions. DESIGN: Oral inquiry. SETTING: Hospitals in the area of Leiden and Amsterdam, the Netherlands. METHODS: 82 medical specialists (41 surgeons and 41 internists) were interviewed and answered questions regarding cost considerations in medical care. They were also asked to determine the probability of success below which they considered an expensive medical treatment useless. RESULTS: The respondents agreed that the government can set limits to care and incorporate cost considerations, but they also indicated that the role of physicians is to treat individual patients. About half the physicians would agree to discontinue treatment when it became too expensive. Decisions regarding the limitation of care should be made by politicians with or without the advice of physicians. The respondents would discontinue (an expensive) treatment (in a presented case) if the probability of success was on average below 12%, but half the physicians said they would accept a lower probability of success for individual patients than they would recommend as a policy. CONCLUSION: Although physicians agreed about the necessity to set limits to medical care, their behaviour in clinical practice appeared to be not always in agreement with this.

Cost Control↗
PubMed1997

Antimicrobial treatment in acute maxillary sinusitis: a meta-analysis.

OBJECTIVE: The aims of this study were to assess which antibiotic is most effective in the treatment of acute maxillary sinusitis in otherwise healthy adults and adolescents, and which has the fewest side effects. DESIGN: To assess the short-term effects of antimicrobial treatments, a meta-analysis was performed using Mantel-Haenszel procedures on 16 comparative, randomized studies with a total number of 3358 patients. No placebo-controlled studies were available. Antimicrobial treatments were categorized according to type, spectrum, beta-lactamase inhibition, and bactericidal effect. Outcomes were clinical cure, clinical success, and adverse events. RESULTS: When studies were analyzed separately, we found significant differences between cefpodoxim and cefaclor in relation to clinical cure, and between loracarbef and doxycycline in relation to clinical success. When data was pooled, sulphonamides were significantly more effective than penicillins in relation to clinical cure, and macrolids were more effective than penicillins in relation to clinical success, whereas cephalosporins caused significantly less adverse events than penicillins. When studies were stratified (standard classic meta-analysis), antibiotics with beta-lactamase inhibition offered significantly more clinical cures than antibiotics without beta-lactamase inhibition. However, this significant effect was only due to one study from Southern Europe, published before 1991. CONCLUSION: Differences in outcome between antimicrobial treatments of acute sinusitis in otherwise healthy adults and adolescents appear to be small. Therefore, the cheapest antimicrobial treatment can be selected.

Acute Disease↗
PubMed1997

Follow-up of colorectal cancer patients: quality of life and attitudes towards follow-up.

The aims of our study were to assess the effect of follow-up on the quality of life of colorectal cancer patients and to assess the attitudes of patients towards follow-up as a function of patient characteristics. Patients who had been treated with curative intent were selected from four types of hospitals. Eighty-two patients were interviewed using a structured questionnaire, whereas 130 patients received the questionnaire by mail. To assess the effect of follow-up on the quality of life, the interviewed patients were randomly allocated to three groups and interviewed at different times in relation to the follow-up visit. Analysis did not show an effect of the follow-up visit on quality of life. Patients reported a positive attitude towards follow-up: it reassured them, they judged the communication with the physician to be positive, and they experienced only slight nervous anticipation and few other disadvantages. Patients reported a strong preference for follow-up, and a large majority would prefer follow-up even if it would not lead to earlier detection of a recurrence. Apart from living situation, no patient characteristics were clearly associated with the attitude towards follow-up. Implications for clinical practice are discussed.

Aged↗
PubMed1997

Women worried about their familial breast cancer risk--a study on genetic advice in general practice.

AIMS: To ascertain whether women who consulted their GP because they perceived themselves as at increased risk of familial breast cancer were indeed at increased risk, and to evaluate potential strategies for assessing genetic risk of breast cancer in general practice. METHODS: Sixty-seven out of 81 women who had consulted their GP for advice about their possible increased risk of developing breast cancer due to breast cancer in the family were interviewed. Familial breast cancer risk was assessed by a clinical geneticist. This assessment was compared with two recent guidelines for referral for genetic counselling. RESULTS: More than half (52%; n = 35) the women had a relative risk of two and over for developing breast cancer, while another half of these 35 (25%; n = 17) had a relative risk of three and over. All the women (n = 17) with a relative risk of three and over were identified by means of the two current guidelines for referral for genetic counselling, while more than half of the women (61%; n = 11) with a relative risk between two and three were identified. CONCLUSIONS: More than half the women concerned about their familial risk of breast cancer are indeed at increased risk of breast cancer. Current guidelines correctly identify women at high risk. However, doubts about the health gain and feasibility of referral warrant caution, and need further investigation.

Adult↗
PubMed1996

How do surgeons' probability estimates of operative mortality compare with a decision analytic model?

The aim of this study is to compare surgeons' estimates of operative mortality of patients with an abdominal aneurysm (= dilation of the aorta) with the operative mortality derived from a decision analytic model and to determine how surgeons use clinical information. Four experienced surgeons are asked to estimate, among other things, the operative mortality of 137 patients. Results concerning the accuracy of surgeons' estimates show that surgeons' average operative mortality estimates are quite accurate as compared to the calculated mortalities. The standard deviations of surgeons' estimates are lower than the standard deviation of the model, however, indicating that the surgeons are not as good in distinguishing the high and low risk patients. Furthermore, surgeons show substantial inconsistencies in the weighing of the clinical information, and also differ from the model in how clinical information is weighed. Finally, when comparing the operative mortalities of the patients who died and those who did not, the model shows a modest, but higher discrimination than the surgeons. Physicians' performance seems to be influenced by the difficulty of the task (i.e. the unpredictability of the event and the multidimensionality of the task). In order to improve physicians' probability estimates, the calculations of the decision model can be used as learning tool.

Aortic Aneurysm, Abdominal↗
PubMed1996

Surveillance versus adjuvant chemotherapy in stage I non-seminomatous testicular cancer: a decision analysis.

In stage I non-seminomatous testicular cancer, the decision between surveillance and adjuvant chemotherapy rests heavily upon the valuation of quality of life. Decision analysis was used to assess at what relapse rate adjuvant chemotherapy is preferred when patients' and clinicians' evaluations are considered. Probabilities were obtained from the literature and from experts. Evaluations of the disease states were obtained from patients (n = 68) and clinicians (n = 50). Results from the model were compared with a treatment preference question, asking for the relapse rate directly. Adjuvant chemotherapy was preferred at relapse rates above 50% when patient evaluations were used. The evaluations of the disease states had a strong impact on the decision. Using clinician evaluations, adjuvant chemotherapy was preferred at relapse rates above 73%. The relapse rates from the treatment preference question were lower: 46% for patients and 35% for clinicians. The results indicate that when patient preferences are accounted for, adjuvant chemotherapy should be considered more often.

Attitude of Health Personnel↗
PubMed1996

The 'utility' of the visual analog scale in medical decision making and technology assessment. Is it an alternative to the time trade-off?

Methods often used for the valuation of health states are the time trade-off (TTO) and the visual analog scale (VAS). The VAS is easier than the TTO and can be self-administered; however it usually leads to lower scores. In the literature a power transformation of group mean VAS scores to TTO scores has been proposed. We were able to replicate this finding of a power function. We found coefficients that were very similar to those from the literature, for 183 cancer patients. The relationship existed independently of disease state and health status.

Case-Control Studies↗
PubMed1996

Acromegaly caused by growth hormone-relating hormone in a patient with multiple endocrine neoplasia type I.

A 51-year-old Caucasian man with multiple endocrine neoplasia (MEN) type I syndrome presented with clinical features of acromegaly. Exploration of the pituitary gland only revealed somatotrophic hyperplasia and his plasma growth hormone (GH) levels remained elevated. Production of growth hormone-releasing hormone (GHRH) by an ectopic tumor was suspected and, after additional investigations, a large pancreatic tumor was detected and removed. As the pancreatic tail contained multiple (occult) adenomas, lifelong follow-up was considered necessary. The patient has been recurrence-free for 10 years. All 19 living relatives of this patient were analysed for endocrine disorders related to MEN I syndrome. A brother was found to suffer from peptic ulcer disease caused by hyperparathyroidism and, during screening for other organ involvement associated with the MEN I syndrome, two tumors were found, one (4 cm) in the pancreatic tail region and one in the right adrenal gland. To date, six other family members have been found to suffer or have suffered from hyperparathyroidism and in a male subject, a prolactinoma and hyperparathyroidism were detected.

Acromegaly↗
PubMed1996

Successful resection of hepatic and pulmonary metastases in a patient with parathyroid carcinoma.

We describe the effect of repeated surgical procedures in a patient with metastatic parathyroid carcinoma over a period of seven years. Initially a subtotal parathyroidectomy was performed for adenomatous hyperplasia. After two years of normocalcemia, hypercalcemia recurred. Two subsequent re-explorations, one of the neck and one of the mediastinum, showed no abnormalities. Histopathologic revision of the primary specimen demonstrated parathyroid carcinoma. Attention was then focused on extra-regional disease, and a hepatic metastasis was detected and successfully resected. Within one year, functional pulmonary metastases occurred. These metastases were treated by four thoracotomies, each providing effective palliation. Eventually the patient died of uncontrollable hypercalcemia seven years after the primary procedure. Even at the time of death there were no signs of recurrent disease in the neck. Parathyroid carcinoma is known to produce local and distant metastases causing severe hypercalcemia. Because medical treatment mostly offers only temporary success and surgery facilitates effective palliation with minimal morbidity, an aggressive surgical approach for functional metastases of parathyroid carcinoma is recommended.

Adult↗
PubMed1996

Spiral CT angiography for suspected pulmonary embolism: a cost-effectiveness analysis.

PURPOSE: To investigate the cost-effectiveness of diagnostic strategies involving spiral computed tomographic (CT) or conventional pulmonary angiography in the diagnosis of suspected pulmonary embolism. MATERIALS AND METHODS: A model was created for analyzing cost-effectiveness on the basis of available literature data. Diagnostic algorithms consisting of combinations of perfusion and ventilation scintigraphy, ultrasound, D-dimer assay, conventional angiography, and spiral CT angiography were compared. Preference for strategies was determined on the basis of the mortality and cost per life saved. RESULTS: For all realistic values of the pretest probability of pulmonary embolism and coexisting deep vein thrombosis and of the specificity of spiral CT angiography, all of the best strategies included spiral CT angiography. With an assumed sensitivity for spiral CT angiography of less than 85%, a conventional angiographic strategy yielded a lower mortality but did not yield superior cost-effectiveness. CONCLUSION: The use of spiral CT angiography is likely to reduce the mortality and improve cost-effectiveness in the diagnostic work-up of suspected pulmonary embolism.

Algorithms↗
PubMed1995

Perioperative mortality of elective abdominal aortic aneurysm surgery. A clinical prediction rule based on literature and individual patient data.

BACKGROUND: Abdominal aortic aneurysm surgery is a major vascular procedure with a considerable risk of (mainly cardiac) mortality. OBJECTIVE: To estimate elective perioperative mortality, we developed a clinical prediction rule based on several well-established risk factors: age, gender, a history of myocardial infarction, congestive heart failure, ischemia on the electrocardiogram, pulmonary impairment, and renal impairment. METHODS: Two sources of data were used: (1) individual patient data from 246 patients operated on at the University Hospital Leiden (the Netherlands) and (2) studies published in the literature between 1980 and 1994. The Leiden data were analyzed with univariate and multivariate logistic regression. Literature data were pooled with meta-analysis techniques. The clinical prediction rule was based on the pooled odds ratios from the literature, which were adapted by the regression results of the Leiden data. RESULTS: The strongest adverse risk factors in the literature were congestive heart failure and cardiac ischemia on the electrocardiogram, followed by renal impairment, history of myocardial infarction, pulmonary impairment, and female gender. The literature data further showed that a 10-year increase in age more than doubled surgical risk. In the Leiden data, most multivariate effects were smaller than the univariate effects, which is explained by the positive correlation between the risk factors. In the clinical prediction rule, cardiac, renal, and pulmonary comorbidity are the most important risk factors, while age per se has a moderate effect on mortality. CONCLUSIONS: A readily applicable clinical prediction rule can be based on the combination of literature data and individual patient data. The risk estimates may be useful for clinical decision making in individual patients.

Adult↗
PubMed1995

Complications of thyroid surgery.

BACKGROUND: The morbidity of thyroid surgery is low. Despite this, some authors advocate a subtotal thyroidectomy instead of a total thyroidectomy, to avoid the higher morbidity associated with a total thyroidectomy. METHODS: We retrospectively evaluated the complications of thyroid surgery in Leiden between January 1, 1982 and October 1, 1990. Three hundred forty-one patients--261 women and 80 men--had 356 operations; 15 patients were operated on twice; there were 152 total hemithyroidectomies, 3 subtotal hemithyroidectomies, 33 total thyroidectomies, 122 bilateral subtotal hemithyroidectomies, 12 combinations of total and subtotal hemithyroidectomies, and 34 other operations. RESULTS: Calculated for the nerves at risk (n = 489), the percentage of permanent recurrent nerve lesions was 3.1 (in the 5 most recent years it was 1.2%). There was no significant difference between total or subtotal (hemi)thyroidectomies. Initial symptomatic hypocalcemia necessitating supplementation was encountered 42 times (12.5%). The occurrence of permanent symptomatic hypocalcemia (6%) was not significantly different between total and subtotal (hemi)thyroidectomies (p = 0.06). The duration of surgery was 137.8 min for bilateral subtotal thyroidectomies and 182.9 min for bilateral total thyroidectomies (p < 0.0001). There was no difference in blood loss between total and subtotal (hemi)thyroidectomies. CONCLUSIONS: Because total thyroidectomy carries a risk of complications similar to that for subtotal thyroidectomy, it is not logical to avoid total resections. If the number of total resections were increased, it is anticipated that fewer reoperations, which involve a relatively high morbidity rate, would have to be performed.

Adolescent↗
PubMed1995

The "utility" of the Time Trade-Off method in cancer patients: feasibility and proportional Trade-Off.

We examined the feasibility and the proportional trade-off assumption of the Time Trade-Off method. Utilities were assessed of the actual health states of 54 testicular and 72 colorectal cancer patients, treated with the curative intent and 29 incurable colorectal cancer patients. Three periods of time were used to assess proportionality: the subject's life expectancy and two shorter periods. Results showed the method to be feasible in curatively treated patients, though the use of life expectancy posed difficulties in some very old subjects. This same difficulty was encountered in patients with symptomatic incurable disease. A two step procedure is proposed as a solution. The proportional trade-off assumption was violated. Utilities for the longer period were smaller than those for the shorter periods. Life expectancy and trade-off did not correlate, though. Remarkable was that many patients were unwilling to trade at all. The implications of the findings are discussed.

Adult↗
PubMed1995

Influence of low dose allopurinol on ischaemia--reperfusion injury during abdominal aortic surgery.

OBJECTIVES: To ascertain whether surgery causes ischaemia-reperfusion (I-R) related injury, if this injury is augmented by preoperative shock, and reduced with low dose allopurinol. DESIGN: Randomised blind placebo controlled trial. SETTING: Surgical laboratory. MATERIAL AND METHODS: 22 pigs were randomly allocated to four groups; OP = operation/placebo, OA = operation/ allopurinol, SOP = shock + operation/placebo, SOA = shock + operation/allopurinol. An aortic tube prosthesis was inserted in all. In groups SOP and SOA preoperative shock was induced by exsanguination. Allopurinol was administered in group OA on the preoperative day and peroperatively, in group SOA during shock and peroperatively. CHIEF OUTCOME MEASURES: Perioperative blood concentrations of thiobarbituric acid reactive species (TBARS), ascorbic acid (AA), albumin, 99mTc-albumin and creatine phosphokinase (CPK) as indicators of oxidative membrane damage, antioxidant activity, microvascular permeability changes and muscular cell damage respectively. MAIN RESULTS: In the OP and OA groups TBARS gradually increased, while AA, 99mTc-albumin and CPK remained unchanged and albumin decreased. No effect of allopurinol was observed in these groups. In the SOP group TBARS and AA were not significantly different from groups OP and OA. Yet, albumin, 99mTc-albumin and CPK decreased significantly more in the SOP group. Compared with the SOP group, allopurinol treatment (SOA) produced lower TBARS and higher AA levels, and reduced the effect of shock on albumin, 99mTc-albumin and CPK concentrations. CONCLUSIONS: Aortic surgery causes no I-R related damage. Pre-operative shock produces I-R related damage, which is reduced by allopurinol.

Allopurinol↗
PubMed1995

Follow-up after colorectal cancer: current practice in The Netherlands.

OBJECTIVE: To assess the current practice of follow-up after operations for colorectal cancer in The Netherlands in comparison with other countries. DESIGN: Postal survey. SETTING: All surgical departments in The Netherlands. MAIN OUTCOME MEASURES: Attitudes of surgeons towards detection and treatment of recurrences after colorectal cancer. RESULTS: Of the 139 questionnaires sent out, 136 (98%) were returned. History taking, physical examination, and colonoscopy for local recurrence and metachronous tumours were used by 90% of the hospitals. Attitudes towards screening for hepatic and pulmonary metastases and regional recurrence varied considerably between hospitals. Similar findings were found in seven surveys from other countries. CONCLUSION: There is no consensus among surgeons regarding the follow-up of patients with colorectal cancer. Randomised controlled trials comparing different follow-up strategies and cost-effectiveness analyses are needed to identify groups of patients that will benefit most from follow-up. Identification of these patients may lead to more agreement between surgeons.

Colorectal Neoplasms↗
PubMed1994

[Surgical strategy in acute or elective sigmoid resection in The Netherlands; survey based on a marketing model].

OBJECTIVE: To gain insight into the operative strategies used by Dutch surgeons for complicated diverticulitis and sigmoid carcinoma, and into the influence of patient risk factors and surgeon's experience on the preferred operative strategy. DESIGN: Descriptive. METHOD: A questionnaire was sent to all 148 members of the Dutch Society of Gastrointestinal Surgery, concerning 32 fictitious patients with sigmoid pathology. It was based on conjoint-analysis, a model used in marketing research. This model analyses qualities that make a product preferable to another product of the same product group. The operative choices were: resection with Hartmann's procedure, resection with primary anastomosis after on-table lavage, or with primary anastomosis only, or no primary resection but diverting stoma only, or some personal technique. The survey focused on experience of the surgeons with the operative procedures, and on treatment choices in four fictitious cases frequently encountered in general surgery. RESULTS: There was little agreement concerning the preferred surgical option for treatment of complicated diverticular disease or sigmoid carcinoma. With the exception of one fictitious young, electively operated 'ideal' patient (resection with primary anastomosis) there is hardly any consensus among the surgeons with respect to preferred treatment. CONCLUSIONS: Reasons to depart from the conceptually optimal treatment (resection and anastomosis) in complicated cases (from the point of view of the surgeon or the patient), and absence of agreement on responsible other treatment could be differences in appraisal of the importance of several risk factors, or differences in acquired decision making strategies. The literature offers no answer to the question which techniques should be preferred under various circumstances.

Adult↗