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Biomedical subjects

J A Knottnerus

Publications and source records attributed to J A Knottnerus.

At least 55 records · Page 3Linked to original sources
PubMed2001

Randomised controlled trial of disclosure of emotionally important events in somatisation in primary care.

OBJECTIVE: To test whether a disclosure intervention improves subjective health and reduces medical consumption and sick leave in somatising patients in general practice. DESIGN: Non-blind randomised controlled trial. SETTING: 10 general practices in the Netherlands. PARTICIPANTS: 161 patients who frequently attended general practice with somatising symptoms. INTERVENTION: Patients in the intervention group were visited two to three times and invited to disclose emotionally important events in their life. Control patients received normal care from their general practitioners. MAIN OUTCOME MEASURES: Use of medical services (drugs and healthcare visits), subjective health, and sick leave assessed by self completion questionnaires after 6, 12, and 24 months. RESULTS: Of the 161 patients, 137 completed the trial (85%). Both groups were comparable at baseline. The intervention had no effect on the main outcome measures at any point. Intervention patients made one more visit to health care (95% confidence interval -4 to 6); the use of medicines did not change in both groups (-1 to 1); subjective health improved 3.6 points more in the control group (-11.2 to 4.3); and disclosure patients were on sick leave one more week (-1 to 3). Patients often had a depression or anxiety disorder for which they were not receiving adequate care. CONCLUSION: Although the intervention was well received by patients and doctors, disclosure had no effect on the health of somatising patients in general practice.

Adult↗
PubMed2001

[Roaming through methodology. XXXIII. Ethics of sample size estimation: less subjects needed for a one-sided than for a two-sided statistical investigation].

In sample size calculations for clinical trials, two-sided statistical testing is the usual starting point. Compared with one-sided testing, this option requires the inclusion of a larger number of study subjects, and a larger number of study events will be needed before a conclusion can be reached. It is therefore ethically relevant to consider in which situations one-sided testing should be the preferred option. One-sided statistical testing is preferable when the research hypothesis is one-sided (is intervention A better and intervention B?), or when only a clearly better result for A compared to B will have clinical consequences (e.g. if A is more cumbersome or more invasive to the patient than B). For the estimation of the number of study subjects needed, one-sided testing should then be assumed. If a new intervention is to be tested by comparison with placebo treatment or with absence of treatment, one-sided testing is an adequate starting point for sample size estimation.

Case-Control Studies↗
PubMed2001

Incidence of and risk factors for asymptomatic peripheral arterial occlusive disease: a longitudinal study.

The current study describes the age- and sex-specific incidence rates and risk factors for asymptomatic and symptomatic peripheral arterial occlusive disease (PAOD) among 2,327 subjects and the incidence of intermittent claudication in asymptomatic PAOD subjects. The study population was selected from 18 general practice centers in the Netherlands. PAOD was assessed with the ankle-brachial blood pressure index, and intermittent claudication was assessed with a modified version of the Rose questionnaire. After 7.2 years, the overall incidence rate for asymptomatic PAOD, using the person-years method, was 9.9 (95% confidence interval (CI): 7.3, 18.8) per 1,000 person-years at risk. The rate was 7.8 (95% CI: 4.9, 20.3) for men and 12.4 (95% CI: 7.7, 24.8) for women. For symptomatic PAOD, the incidence rate was 1.0 (95% CI: 0.7, 7.5) overall, 0.4 (95% CI: 0.3, 10.0) for men, and 1.8 (95% CI: 1.0, 10.3) for women. Multivariate analyses showed that increasing age, smoking, hypertension, and diabetes mellitus were the most important risk factors. The overall incidence rate for intermittent claudication among PAOD subjects who were asymptomatic at baseline was 90.5 per 1,000 person-years at risk (95% CI: 36.4, 378.3). The incidence of asymptomatic PAOD was higher than the incidence of symptomatic PAOD, with women developing PAOD more often than men. In the development of preventive strategies, modification of atherosclerotic risk factors, such as smoking, hypertension, and diabetes, should be the main goals.

Adult↗
PubMed2001

Psychosocial patient characteristics and GP-registered chronic morbidity: a prospective study.

OBJECTIVE: The aim of this study was to get a profile of patients who are vulnerable to get multiple chronic, recurrent or high-impact diseases in a limited time period. We studied the incidence rates of morbidity and multimorbidity, and the influence of psychosocial characteristics on their occurrences. METHOD: Cohort study with 3551 subjects. Baseline measurement of psychosocial characteristics and a 2-year follow-up period for morbidity. The relations were evaluated using multiple logistic regression analysis. RESULTS: After adjustment for basic socio-demographic variables, a high internal locus of control belief was found to be protective [odds ratio (OR)=0.82] for the occurrence of morbidity, negative life events increased the risk (OR=1.22). Characteristics specifically protective for the occurrence of multimorbidity as compared to monomorbidity were: a high internal locus of control belief (OR=0.73), living as a couple or in a family as compared to living alone (OR=0.68) and a large social network (OR=0.41). CONCLUSION: It appears that certain patient characteristics are specifically related to the occurrence of multimorbidity. This provides opportunities for the future development of preventive interventions.

Adaptation, Psychological↗
PubMed2001

Problems in determining occurrence rates of multimorbidity.

This article describes methodological decisions that have to be made when studying multiple pathology and presents appropriate analytical techniques. The main question of this article is: how can comorbidity and multimorbidity be operationalized with respect to the number and type of diseases studied, and which analytic approaches are available for the evaluation of multiple pathology? Choices regarding the number and type of diseases studied have great impact on the observed incidence and prevalence rates of comorbidity and multimorbidity. These rates are largely dependent on age, sex, and other determinants. In addition to crude descriptive measures, odds ratios and relative risks can be used to study comorbidity, whereas multimorbidity can be studied using observed/expected ratios. While basic analyses of comorbidity can be performed using standard statistical packages, two additional programs were developed for the analysis of the distribution of multimorbidity and statistically unexpected comorbidity, respectively. As some analyses are addressing multicomparisons, external validity testing is recommended.

Aged↗
PubMed2001

Systematic reviews of diagnostic research. Considerations about assessment and incorporation of methodological quality.

The aim of this paper is to provide a theoretical background for performing and reading systematic reviews of diagnostic studies. We first discuss items for assessment of methodological quality in diagnostic studies and then present methods on how to incorporate these quality measures in systematic reviews. The items of internal validity determine whether the presented results of the individual studies are unbiased and can be trusted. Items of external validity determine to what extent the results are applicable outside the population in which the study was performed. The issues concern the adequacy of the study population, the performance and interpretation of the diagnostic tests and the presentation of the results. Several methods exist for incorporation of issues of methodological quality into systematic reviews, such as subgroup analyses, meta-regression analysis, and methodological scores. Publications of diagnostic studies should provide sufficient information to enable assessment of the methodological quality. Furthermore, publication of results of subgroup analyses should be promoted. Methodological criteria lists might help to improve the quality of systematic reviews of diagnostic research. With the items of methodological quality in mind the general practitioner might be better equipped to critically read and interpret diagnostic reviews.

Epidemiologic Studies↗
PubMed2001

Physical activity in daily life in patients with chronic low back pain.

OBJECTIVES: To evaluate disuse (ie, a decreased daily physical activity level) in patients with chronic low back pain (LBP) and to evaluate the construct validity of accelerometry for measuring physical activity in daily life. DESIGN: Case-control study in a cross-sectional design; comparison of accelerometry to the criterion standard (doubly labeled water technique). SETTING: Normal daily living (unrestricted by the measurement devices). PATIENTS: Thirteen patients with chronic nonspecific LBP and 13 age- and gender-matched healthy controls. MAIN OUTCOME MEASURES: Physical activity in daily life, expressed as whole-body acceleration measured with a triaxial accelerometer (Tracmor), and as the ratio between average daily metabolic rate (ADMR), measured by the doubly labeled water technique, and resting metabolic rate (RMR), measured by the ventilated hood. Both techniques were used simultaneously for 14 days. RESULTS: Mean physical activity level in patients and controls did not differ significantly. The correlation between the Tracmor and ADMR and RMR was .72 (p < .01). CONCLUSIONS: Decreased physical activity levels in this sample of chronic LBP patients was not confirmed. The Tracmor is a valid instrument for measuring daily activity in LBP patients.

Activities of Daily Living↗
PubMed2001

Indicators of childhood adversity in somatisation in general practice.

OBJECTIVE: To identify medical and psychosocial indicators of childhood adversity in somatising patients in primary care. DESIGN: Retrospective questionnaires and interviews. SETTING: Primary health care in The Netherlands. SUBJECTS: Three-hundred-and-seventy-four somatising frequent attenders in 27 general practices between 20 and 45 years of age. MAIN OUTCOME MEASURES: Major problems in childhood. RESULTS: The questionnaire on childhood problems reflected acceptable validity against a structured interview in 77 patients (correlation 0.69); however, the item "abuse" was underreported in the questionnaire. Four out of five patients reported one or more major childhood problems. Childhood adversity was indicated independently by chronic difficulties in present relations and by genital-sexual symptoms of patients. CONCLUSION: When GPs want to take a more active approach towards somatisers they may show interest in the childhood and life story of patients, especially when patients are known with chronic difficulties in relations and genital-sexual symptoms.

Adult↗
PubMed2001

Climacteric complaints in the community.

BACKGROUND: At the onset of the climacteric, healthy middle-aged women present with a variety of complaints, especially in general practice. In these first years of entering the menopause, vaginal blood loss alters from irregular periods to complete amenorrhoea. According to these different menstrual patterns, we can distinguish a pre-, peri- and postmenopausal phase. It could be useful to know whether specific climacteric complaints are related to these different phases. OBJECTIVE: The aim of this study was to investigate the relationship between climacteric complaints and the menstrual pattern during the menopausal transition in a population-based cross-sectional survey of healthy middle-aged women. METHODS: All women aged 47-54 years, living in the city of Eindhoven, were invited to participate in the Eindhoven Osteoporosis Study (EPOS); 6648 (78%) agreed to participate. All women completed a questionnaire concerning climacteric complaints. Climacteric status was defined by menstrual history. Odds ratios (ORs) were obtained for the relationship between climacteric status and climacteric complaints. Multiple logistic regression analysis was carried out, with climacteric status as the dependent variable. RESULTS: Of the 27 items in the questionnaire concerning climacteric complaints, seven were significantly different between all three climacteric phases (P: < 0.1). After multiple logistic regression analysis, comparing peri- and premenopause, only flushing (OR 5.9) was significantly different. Between post- and perimenopause, seven symptoms appeared to be different: three urogenital complaints [vaginal dryness (OR 1.6), vaginal discharge (OR 0.4) and pain during intercourse (OR 1.9)], three vasomotor symptoms [daytime sweating (OR 1.4), night-time sweating (OR 0.7) and flushing (OR 1.9)] and, finally, insomnia (OR 1.3). When comparing post- and premenopause, flushing (OR 13.4), insomnia (OR 2.1) and depressed mood (OR 0.6) were significantly different, in addition to three urogenital symptoms: vaginal dryness (OR 2.6), vaginal discharge (OR 0.3) and pain during intercourse (OR 2.1). CONCLUSION: The major findings of the study are that flushing is strongly associated with the transition from pre- to perimenopause, while urogenital complaints, daytime sweating and insomnia are more prominent in the transition from peri- to postmenopause.

Adult↗
PubMed2001

Barriers in the care of patients who have experienced a traumatic event: the perspective of general practice.

BACKGROUND: Previous research has indicated that GPs encounter barriers in the care of patients who have experienced a traumatic event. OBJECTIVES: The aims of the present study were to map barriers GPs encounter in the care of patients who experience a traumatic event and solutions for these barriers, and to estimate the influence of GP characteristics on the number of barriers experienced. METHODS: Telephone interviews were conducted among a sample of 500 Dutch GPs stratified by sex. Topics covered barriers in the care of victims of: accidents, incest in the past, ongoing physical or sexual abuse of adults, and ongoing physical or sexual abuse of children. RESULTS: The response rate was 44%. GPs are regularly confronted with patients who have experienced a traumatic event. GPs experience 10% barriers in care of patients who have difficulties getting over an accident, 13% in the care of incest victims, 16% in the care of adults who are physically or sexually abused, and 20% in the care of physically or sexually abused children. Most of the GPs recently updated their knowledge of care of victims of traumatic events, but still the majority feel in need of additional expert training. CONCLUSION: GPs experience the greatest number of barriers in the care of children who are abused. GP characteristics were not related to the number of barriers. However, seeing more victims was related to fewer barriers. To facilitate GP care of victims of traumatic events, GP training and continuing medical education should focus especially on skills education regarding the detection and initial treatment of traumatic events of ongoing physical or sexual abuse.

Accidents↗
PubMed2001

Chest pain in general practice or in the hospital emergency department: is it the same?

OBJECTIVE: The aim of the present study was to provide a description of the impact of setting on the diagnostic case mix that is identified in consecutive patients presenting with chest pain. METHODS: A cross-sectional study was carried out of patients presenting with chest pain according to setting: general practice, self-referred, referred or arriving by ambulance at the hospital emergency department (ED). GPs from 25 general practices situated in the Flemish part of Belgium were recruited, and the hospital involved was a major teaching hospital in the same area. A total of 320 patients in general practice and 580 patients in the hospital ED were studied. The difference in prevalence rates for the major diagnostic categories was the main outcome measure. RESULTS: Gastrointestinal disorders, musculoskeletal problems and psychopathology are identified more frequently in general practice; and serious lung diseases and cardiovascular diseases in the hospital ED. Within the hospital, there is a strong trend towards increasing frequency of serious cardiovascular diseases including unstable angina (P = 0.01) from self-referred to referred patients and those rushed in by ambulance. The opposite trend was identified for respiratory (P = 0.02) and musculoskeletal (P = 0.07) diseases. The diagnostic case mix in self-referred patients tends to be more similar to the other groups of hospital patients than to patients in general practice. CONCLUSIONS: There is a large difference between the diagnostic case mix presented in general practice compared with the ED and among referral-related subgroups within the hospital emergency department.

Adult↗
PubMed2000

[Evaluation of social relevance of applied health research: a rough indicator may be the significance of publishing in national professional journals].

Evaluation of health research output can have important implications for departments, institutes and individual careers. Typically, a peer review of the scientific quality of the output is central in this evaluation, increasingly with a bibliometric analysis at its core. Such an analysis is based on counting publications and citations from journals included in the (Social) Science Citation Index. Although the methodology is still far from perfect, there seems to be consensus on how to evaluate the scientific quality. This is in contrast to the evaluation of the social relevance of health research output, as there is no agreement on its importance, the dimensions involved, or the relevant methods of assessment. There is a need for the assessment of the social impact of applied health research, next to its scientific quality. As an initial rough approximation, counting publications in national professional journals may provide a suitable indicator of the social relevance of the research output.

Bibliometrics↗
PubMed2000

Hormonal substitution during menopause: what are we treating?

OBJECTIVES: It is suggested that during menopausal transition, women with vasomotor symptoms benefit from HRT, (hormone replacement therapy) whereas, the use of HRT for other cognitive-vegetative symptoms is questionable. METHODS: The occurrence of menopausal complaints and depressive symptoms was assessed cross-sectionally in 5896 Dutch Caucasian women (47-54 years) of a large community sample in the city of Eindhoven, The Netherlands. Menopausal complaints were assessed using a 22 items self-rating scale (consisting of a vasomotor, uro-genital and a cognitive-vegetative subscale). Depressive symptoms were assessed using the Edinburgh depression scale (EDS). Differences in mean scores were analysed between groups using ANOVA. The independent relationship of depressive symptoms to the intensity of menopausal complaints was assessed, by multiple linear regression analysis. RESULTS: Women using HRT showed the highest scores on all subscales. Oral contraceptive users had significantly lower scores on the vasomotor subscale compared to HRT users and to non users. Depressive symptoms contributed the most, to the explained variance on scores on the menopausal subscales. CONCLUSIONS: Women during menopause presenting several complaints, other than vasomotor origin might be suffering from underlying depression which makes it questionable to prescribe HRT for the latter symptoms.

Affect↗
PubMed2000

Somatisation in primary care: clinical judgement and standardised measurement compared.

BACKGROUND: In daily practice general practitioners (GPs) generally rely on their clinical judgement in assessing whether patients somatise distress. Nevertheless, conclusions derived from research on somatisation in primary care are largely based on standardised measurements of somatisation. We investigated the relation between GPs' clinical judgement of somatisation and a somatisation research instrument (DSM-III-R), and examined how both operationalisations of somatisation related to other important variables. METHODS: In nine general practices, 407 frequently attending patients answered a questionnaire on somatisation symptoms, while the GPs gave their judgement on somatisation and communication for each patient. Other variables were extracted from the registered health status of the patients. RESULTS: We found a weak association (correlation: 0.27) between the GPs' judgement and the research instrument; however, relations with other variables showed that both operationalisations were very similar constructs. The research instrument incorporated more psychological problems (depression and anxiety), while the GPs' judgement of somatisation was more influenced by attendance rate and by aspects of communication with the patient. CONCLUSION: For research addressing somatisation in primary care as a practical clinical problem, the operationalisation of somatisation should include the clinical judgement of the practitioner as well, thereby widening the focus from co-morbid mental disturbances to communication aspects.

Adult↗
PubMed2000

Marginal impact of psychosocial factors on multimorbidity: results of an explorative nested case-control study.

This study examines differences between subjects with zero, one or two or more new diseases in a period of three years, with regard to demographic characteristics, socioeconomic status, life style, medical family history and current diseases in the family, psychological and sociological characteristics. This was studied using a primary care based nested case-control study. Data were available from 3745 cases and controls, all aged 20 years and older. All subjects were sampled from the Registration Network Family Practices, which is a computerised continuous primary care database. Cases were defined as subjects with new multimorbidity (two or more new diseases) registered in a period of three years and two groups of controls were operationalised as subjects with either one or no new diseases registered in the same period. Determinants were assessed by means of a postal questionnaire. Increasing age, higher number of previous diseases and low socioeconomic status were strongly associated with both morbidity and multimorbidity. After adjustment for these basic variables, the occurrence of multimorbidity was more frequent among subjects who did not report (volunteer) work or study, who had an active coping style, a high occupational class and an external locus of control. Profiles for subjects at risk for morbidity and multimorbidity seem to differ.

Adaptation, Physiological↗
PubMed2000

The construction of a patient record-based risk model for recurrent falls among elderly people living in the community.

BACKGROUND: Predictive models of fall risk in the elderly living in the community may contribute to the identification of elderly at risk for recurrent falling. OBJECTIVES: Our aim was to investigate occurrence, determinants and health consequences of falls in a community-dwelling elderly population and the contribution of data from patient records to a risk model of recurrent falls. METHODS: A population survey was carried out using a postal questionnaire. The questionnaire on occurrence, determinants and health consequences of falls was sent to 2744 elderly persons of 70 years and over, registered in four general practices (n = 27 000). Data were analysed by bivariate techniques and logistic regression. RESULTS: A total of 1660 (60%) responded. Falls (> or =1 fall) in the previous year were reported by 44%: one-off falls by 25% and recurrent falls (> or =2 falls) by 19%. Women had significantly more falls than men. Major injury was reported by 8% of the fallers; minor injury by 49%. Treatment of injuries was by the GP in 67% of cases. From logistic regression, a risk model for recurrent falls, consisting of the risk factors female gender, age 80 years or over, presence of a chronic neurological disorder, use of antidepressants, problems of balance and sense organs and complaints of muscles and joints was developed. The model predicted recurrent falls with a sensitivity of 64%, a specificity of 71%, a positive predictive value of 42% and a negative predictive value of 86%. CONCLUSION: A risk model consisting of six variables usually known to the GP from the patient records may be a useful tool in the identification of elderly people living in the community at risk for recurrent falls.

Accidental Falls↗