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Hak E, Opstelten W, Looijmans-van den Akker I, Knottnerus JA. [Influenza vaccination in the elderly: effectiveness not in doubt]. NEDERLANDS TIJDSCHRIFT VOOR GENEESKUNDE 2008; 152:1081-1083. [PMID: 18552059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In a recent review the effectiveness of influenza vaccination in the elderly was brought into question. Selection bias, which would occurr if healthy people were more likely to be vaccinated than their infirm peers, and the use of non-specific outcomes, such as death from all causes, were considered to have contributed to the effectiveness of the vaccine as to morbidity and mortality being overestimated. However, a recent study has shown that even when potential bias and residual confounding were addressed, influenza vaccination was associated with a significant reduction in the risk of influenza-related morbidity and mortality among community-dwelling elderly persons. Direct estimates of influenza-related morbidity were hampered by delayed and insufficiently sensitive diagnostics. Excess studies, however, comparing morbidity and mortality during periods with and without influenza predominance, present reliable indirect estimates in favour of vaccination. While the vaccination rate of high-risk subjects in The Netherlands is traditionally high, the age limit for influenza vaccination was lowered from 65 to 60 in 2008, taking into account influenza-related morbidity and mortality in healthy people aged 60 to 65 years and the undisputed effectiveness of vaccination against influenza.
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Leone SS, Huibers MJH, Knottnerus JA, Kant IJ. Similarities, overlap and differences between burnout and prolonged fatigue in the working population. QJM 2007; 100:617-27. [PMID: 17921196 DOI: 10.1093/qjmed/hcm073] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Burnout and prolonged fatigue are related but distinct concepts that have seldom been empirically compared. AIM To examine similarities, overlap and differences between burnout and prolonged fatigue. DESIGN Observational study. METHODS We analysed baseline data from the Maastricht Cohort Study on Fatigue at Work (n = 12 140). The discriminative abilities of the Checklist Individual Strength (CIS) and the Maslach Burnout Inventory-General Survey (MBI-GS) were evaluated using principal component analysis. Overlap, similarities and differences regarding health, work and demographic factors between subgroups were assessed. RESULTS The discriminative abilities of the CIS and MBI-GS appeared to be moderate. Prolonged fatigue and burnout cases overlapped considerably. The subgroup consisting of cases with concurrent fatigue and burnout tended to have poorer outcomes in terms of health and work factors than the subgroups with either prolonged fatigue or burnout. Similar patterns were found for subjective fatigue and exhaustion. DISCUSSION There appear to be some relevant differences between burnout and prolonged fatigue, with respect to work and health factors. Burnout and prolonged fatigue can occur both separately and simultaneously. Having both conditions simultaneously seems to be associated with worse outcomes than having either alone.
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van Schayck CP, Knottnerus JA. No clinical evidence base to support the hygiene hypothesis. PRIMARY CARE RESPIRATORY JOURNAL : JOURNAL OF THE GENERAL PRACTICE AIRWAYS GROUP 2007; 13:76-9; discussion 80-2. [PMID: 16701644 PMCID: PMC6750670 DOI: 10.1016/j.pcrj.2004.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The hygiene hypothesis is a popular explanation for recent increases in allergy in the western world. This hypothesis suggests that development of allergy (or asthma) could be prevented by exposure to immune stimulants such as viruses, bacteria and endotoxins, in particular in the prenatal period or early childhood. How evidence-based are the observations which support the hygiene hypothesis? All clinical epidemiological indications in favour of the hypothesis are based on observational (cross-sectional and cohort) studies and not on observations in randomised controlled intervention studies. In cross-sectional studies no causal relationships can be assessed with sufficient validity. Also in cohort studies there are validity problems, as the exposure is not determined by chance (by means of randomisation) and could be influenced by behaviour. And behaviour might well be a confounder, since it can be associated with both exposure and outcome. A problem is that, without being appropriately tested in well designed prospective research, the hygiene hypothesis has currently already become so popular in the news media that an increased occurrence of asthma might even be induced as a result of an increased exposure. Although the currently available evidence to support the hygiene hypothesis is poor, it appears that the hypothesis has to some become a matter of faith or ideology. Scientists should take care that messages imparted to the general public do not go beyond or conflict with existing evidence.
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Fransen GAJ, Janssen MJR, Muris JWM, Mesters I, Knottnerus JA. Measuring the severity of upper gastrointestinal complaints: does GP assessment correspond with patients' self-assessment? Fam Pract 2007; 24:252-8. [PMID: 17493955 DOI: 10.1093/fampra/cmm011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Questionnaires are frequently used to measure the severity of gastrointestinal (GI) complaints. These questionnaires can either be filled out by the physicians or by the patients, but it is not clear whether these scores correspond. This study aimed to investigate the interrater agreement between physician-reported severity and patient-reported severity concerning the patients' upper GI complaints. METHODS In a prospective observational study, the severity of eight GI complaints was registered by both patients and GPs independently on a seven-point scale (n = 316) before and after treatment with esomeprazole. Weighted kappa values for the agreement on the severity and simple kappa values for the agreement on the absence or presence of symptoms were calculated. RESULTS The weighted kappa values ranged from 0.14 to 0.68 indicating poor to moderate agreement. The agreement on the presence or absence of symptoms was similar. Several systematic differences in scoring were found: the GPs tended to underestimate the severity of belching, nausea, early satiety, vomiting and upper and lower abdominal pain. Furthermore, the treatment effect for belching and lower abdominal pain was more often overestimated, while the treatment effect for nausea was more often underestimated by the GP. CONCLUSION The agreement between GP and patient is low. The differences in scoring should be kept in mind when comparing physician-reported outcomes with patient-reported outcomes.
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Friesema IHM, Zwietering PJ, Veenstra MY, Knottnerus JA, Garretsen HFL, Lemmens PHHM. Alcohol intake and cardiovascular disease and mortality: the role of pre-existing disease. J Epidemiol Community Health 2007; 61:441-6. [PMID: 17435212 PMCID: PMC2465695 DOI: 10.1136/jech.2006.050419] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2006] [Indexed: 11/04/2022]
Abstract
OBJECTIVES Pre-existing conditions have been postulated as possible causes of the J-shaped relationship between alcohol intake and cardiovascular disease. Two research questions have been addressed in this paper. First, whether never drinkers and former drinkers differ from moderate drinkers in terms of health, and if so, which health problems contribute to this difference. Second, whether the U-shaped relationship between current alcohol intake and cardiovascular disease or all-cause mortality could in part be explained by difference in pre-existing disease burden. DESIGN, SETTING AND PARTICIPANTS A prospective case-cohort, the Lifestyle and Health Study, consisting of 16,210 men and women aged between 45 and 70 years. Alcohol intake and risk factors were assessed at baseline with a self-administered questionnaire. Medical information was obtained from general practitioners. Cardiovascular events and mortality were followed for a period of 5 years (1996-2001). MAIN RESULTS Never drinkers and former drinkers were less healthy than moderate drinkers. They rated their health more often as poor, and often had more diseases, such as cardiovascular disease, diabetes, and also alcohol-related diseases. The difference in disease burden did not change the observed relationship between alcohol intake and cardiovascular events, and only partially changed the U-shaped relationship between alcohol intake and all-cause mortality. CONCLUSIONS The found difference in health between never drinkers and former drinkers compared with moderate drinkers appeared to be only a partial explanation of the observed relationships between alcohol intake and cardiovascular disease, and between alcohol intake and all-cause mortality.
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Meuwissen LE, Gorter AC, Segura Z, Kester ADM, Knottnerus JA. Uncovering and responding to needs for sexual and reproductive health care among poor urban female adolescents in Nicaragua. Trop Med Int Health 2007; 11:1858-67. [PMID: 17176351 DOI: 10.1111/j.1365-3156.2006.01741.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND To meet the needs of female adolescents from low-income urban areas for sexual and reproductive health (SRH) care, vouchers providing free-of-charge access to SRH care at 19 primary care clinics were distributed in Managua, Nicaragua. These vouchers substantially increased the use of services, demonstrating that many adolescents are willing to use such services, if readily accessible. The voucher redemption made it possible to identify the nature of existing, but largely unmet, needs for SRH care. METHOD The medical files from 3301 consultations with female adolescents were analysed using descriptive statistical methods and multiple logistic regression. RESULTS Female adolescents presented SRH problems that merited medical attention. The mean number of problems presented was 1.5 per consultation: 34% of the vouchers were used for contraceptives, 31% for complaints related to sexually transmitted infection (STI) or reproductive tract infection (RTI), 28% for advice/counselling, 28% for antenatal check-up and 18% for pregnancy testing. A new category of health care users emerged: sexually active girls who were neither pregnant nor mothers and who sought contraceptives or STI/RTI treatment. Contraceptive use doubled among the sexually active non-pregnant voucher redeemers. Consultation with a female doctor younger than 36 years was associated with a higher chance of having contraceptives prescribed. CONCLUSION Accessible and appropriate SRH care has the potential to make an important contribution to the increased contraceptive use, decreased risk of unwanted teenage pregnancies and decreased prevalence of STIs/RTIs among underserved adolescents. Once adolescents access the services, providers have a crucial role in ensuring current and continuing needs are met.
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Meuwissen LE, Gorter AC, Kester ADM, Knottnerus JA. Can a comprehensive voucher programme prompt changes in doctors' knowledge, attitudes and practices related to sexual and reproductive health care for adolescents? A case study from Latin America. Trop Med Int Health 2006; 11:889-98. [PMID: 16772011 DOI: 10.1111/j.1365-3156.2006.01632.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To evaluate whether participation in a competitive voucher programme designed to improve access to and quality of sexual and reproductive health care (SRH-care), prompted changes in doctors' knowledge, attitudes and practices. METHODS The voucher programme provided free access to SRH-care for adolescents. Doctors received training and guidelines on how to deal with adolescents, a treatment protocol, and financial incentives for each adolescent attended. To evaluate the impact of the intervention on doctors, nearly all participating doctors (n = 37) were interviewed before the intervention and 23 were interviewed after the intervention. Answers were grouped in subthemes and scores compared using nonparametric methods. RESULTS The initial interviews disclosed deficiencies in doctors' knowledge, attitudes and practices relating to adolescent SRH-issues. Gender and age of the doctor were not associated with the initial scores. Comparing scores from before and after the intervention revealed significant increases in doctors' knowledge of contraceptives (P = 0.003) and sexually transmittable infections (P < 0.001); barriers to contraceptive use significantly diminished (P < 0.001 and P = 0.003); and some attitudinal changes were observed (0 = 0.046 and P = 0.11). Doctors became more aware of the need to improve their communication skills and were positive about the programme. CONCLUSIONS This study confirmed provider related barriers that adolescents in Nicaragua may face and reinforces the importance of focusing on the quality of care and strengthening doctors' training. Participation in the voucher programme resulted in increased knowledge, improved practices and, to a lesser extent, in changed attitudes. A competitive voucher programme with technical support for the participating doctors can be a promising strategy to prompt change.
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Huibers MJH, Leone SS, Kant IJ, Knottnerus JA. Chronic fatigue syndrome-like caseness as a predictor of work status in fatigued employees on sick leave: four year follow up study. Occup Environ Med 2006; 63:570-2. [PMID: 16698810 PMCID: PMC2078121 DOI: 10.1136/oem.2005.023176] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To assess whether CFS-like caseness (meeting the criteria for chronic fatigue syndrome (CFS)) predicts work status in the long term. METHODS Prospective study in a sample of fatigued employees absent from work. Data were collected at baseline and four years later, and included CFS-like caseness and work status (inactive work status and full work incapacity). RESULTS CFS-like cases at baseline were three times more likely to be unable to work at follow up than fatigued employees who did not meet CFS criteria at baseline (ORs 3-3.3). These associations grew even stronger when demographic and clinical confounders were controlled for (ORs 3.4-4.4). CONCLUSION A CFS-like status (compared to non-CFS fatigue) proved to be a strong predictor of an inactive work status and full work incapacity in the long term. Since little is known about effective interventions that prevent absenteeism and work incapacity or facilitate return to work in subjects with chronic fatigue, there is a great need for powerful early interventions that restore or preserve the ability to work, especially for workers who meet criteria for CFS.
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Veenstra MY, Friesema IHM, Zwietering PJ, Garretsen HFL, Knottnerus JA, Lemmens PHHM. Lower prevalence of heart disease but higher mortality risk during follow-up was found among nonrespondents to a cohort study. J Clin Epidemiol 2006; 59:412-20. [PMID: 16549264 DOI: 10.1016/j.jclinepi.2005.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 08/11/2005] [Accepted: 08/20/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The primary aim was to assess the association between response behavior and health status at baseline, and survival in a 5-year follow-up period. A secondary aim was to assess whether reasons for nonresponse were associated with health status at baseline. STUDY DESIGN AND SETTING Data came from a prospective study cohort consisting of 31,349 men and women aged 45-70 years. Objective retrospective and prospective health information derived from general practitioner registries was available for both respondents and nonrespondents. RESULTS Results show that among respondents coronary heart disease was more prevalent. Compared with respondents, noncontacts had a higher mortality risk during follow-up. Refusals had hypercholesterolemia more often than did noncontacts, and coronary heart disease or diabetes mellitus less often. CONCLUSION The paradoxical results that respondents are less healthy at baseline but prospectively have a lower mortality risk may point to a selection effect indicating that the 'worried ill' are more inclined to participate. This effect could imply that observed relationships between risk factors or behaviors and outcomes in cohort studies may be attenuated.
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Spigt MG, Knottnerus JA, Westerterp KR, Olde Rikkert MGM, Schayck CP. The Effects of 6 Months of Increased Water Intake on Blood Sodium, Glomerular Filtration Rate, Blood Pressure, and Quality of Life in Elderly (Aged 55â75) Men. J Am Geriatr Soc 2006; 54:438-43. [PMID: 16551310 DOI: 10.1111/j.1532-5415.2005.00606.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To study whether there are any negative or positive effects of 6 months of increased fluid intake in reasonably healthy elderly men. DESIGN Randomized trial. SETTING Community-based. PARTICIPANTS One hundred forty-one healthy participants aged 55 to 75. INTERVENTION One group was given the advice to increase their daily fluid intake by 1.5 L of water; the other group was given placebo medication (8 mL inactive syrup per day). MEASUREMENTS At 6 months blood sodium, glomerular filtration rate (GFR), blood pressure, and quality of life (QOL) were measured. The changes in water turnover were measured using deuterium. RESULTS Most subjects did not manage to increase their fluid intake by 1.5 L. The average increase in the intervention group was approximately 1 L. Twenty-four-hour water turnover in the water group was 359 mL (95% confidence interval=171-548) higher than that of the control group at 6-month follow-up. Blood pressure, sodium level, GFR, and QOL did not change significantly in either group during the intervention period. In addition, the cases reporting a worsening on the effect measures were equally distributed over the two study groups. CONCLUSION The advice to increase fluid intake by 1.5 L had no negative effects in reasonably healthy men aged 55 to 75.
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Meuwissen LE, Gorter AC, Knottnerus JA. Perceived quality of reproductive care for girls in a competitive voucher programme. A quasi-experimental intervention study, Managua, Nicaragua. Int J Qual Health Care 2006; 18:35-42. [PMID: 16421187 DOI: 10.1093/intqhc/mzi073] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To determine whether female adolescents from low-income areas in Managua were satisfied with the sexual and reproductive health (SRH) care provided through a competitive voucher programme and to analyse the determinants of their satisfaction. DESIGN A community-based quasi-experimental intervention study from 2000 to 2002. SETTING Low-income areas of Managua. INTERVENTION Distribution of 28,711 vouchers giving adolescents free-access to SRH care in 19 clinics; training and support for health care providers. STUDY PARTICIPANTS A random sample of 3009 girls from 12 to 20 years completed self-administered questionnaires: 700 respondents had used this care in the last 15 months, 221 with voucher (users-with-voucher) and 479 without voucher (users-without-voucher). MAIN OUTCOME MEASURES User satisfaction; Satisfaction with clinic reception; Clarity of doctors' explanations. RESULTS User satisfaction was significantly higher in users-with-voucher compared with users-without-voucher [Adjusted odds-ratio (AOR) = 2.2; 95% confidence interval (95% CI) = 1.2-4.0]. Voucher use was associated with more frequent satisfaction with clinic reception, especially among sexually active girls not yet pregnant or mother (AOR = 6.9; 95% CI = 1.5-31.8). The clarity of doctors' explanations was not perceived differently (AOR = 1.4; 95% CI = 0.9-2.2). User satisfaction was highly correlated to satisfaction with clinic reception and clarity of doctors' explanations (P < 0.001). Longer consultation times, shorter waiting times, older age, and having a female doctor positively influenced user satisfaction. CONCLUSION Voucher use by teenage girls was associated with a better perceived SRH care. This is an important result, given the crucial role user satisfaction plays in adoption and continued use of health care and contraceptives. Though more research is needed, confidential and guaranteed access appear key factors to voucher success.
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Spigt MG, Kuijper EC, Schayck CP, Troost J, Knipschild PG, Linssen VM, Knottnerus JA. Increasing the daily water intake for the prophylactic treatment of headache: a pilot trial. Eur J Neurol 2006; 12:715-8. [PMID: 16128874 DOI: 10.1111/j.1468-1331.2005.01081.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dehydration is commonly believed to result in headache, but the effectiveness of increasing the water intake in patients who frequently suffer from headaches has not been studied thus far. In a pilot study, we examined the possible effects and feasibility of increased water intake in headache patients. Eighteen headache patients (all had migraine, two also had tension-type headache) were randomly allocated to placebo medication, or the advice to additionally drink 1.5 l of water per day, for a period of 12 weeks. Effect measurements consisted of a 2 weeks headache diary and the Migraine Specific Quality of Life (MSQOL) questionnaire. The advice to increase the daily fluid intake by 1.5 l increased the fluid intake in the intervention group by approximately 1 l. This reduced the total hours of headache in 2 weeks by 21 h (95% CI: -48 to 5). Mean headache intensity decreased by 13 mm (95% CI: -32 to 5) on a visual analogue scale (VAS). The effects on MSQOL, number of headache episodes, and medication seemed to be small. The data of the present study suggest a reduction in the total number of hours and intensity of headache episodes after increased water intake. Our results seem to justify larger scaled research on the effectiveness of increased water intake in headache patients.
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Schönberger HJAM, Dompeling E, Knottnerus JA, Maas T, Muris JWM, van Weel C, van Schayck CP. The PREVASC study: the clinical effect of a multifaceted educational intervention to prevent childhood asthma. Eur Respir J 2005; 25:660-70. [PMID: 15802340 DOI: 10.1183/09031936.05.00067704] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
As asthma is the most common chronic disease in childhood, much attention is directed towards primary prevention. Here, the clinical effectiveness of a multifaceted educational prevention was studied. A total of 476 high-risk children were recruited during the prenatal period by general practitioners and randomised to either: 1) a control group, receiving usual care; or 2) an intervention group in which families received instruction from nurses on how to reduce exposure of newborns to mite, pet and food allergens, and passive smoking. A total of 443 infants were followed-up for 2 yrs. At 2 yrs of age, the intervention group (n = 222) had less asthma-like symptoms, including wheezing, shortness of breath and night-time cough, than the control group (n = 221). No significant differences in total and specific immunoglobulin E were found between the groups. During the first 2 yrs of life, the incidence of asthma-like symptoms was similar in both groups; however, subanalysis revealed a significant reduction in the female, but not in the male, intervention group. In conclusion, the intervention used in this study was not effective in reducing asthma-like symptoms in high-risk children during the first 2 yrs of life, although it was modestly effective at 2 yrs. Follow-up is necessary to confirm whether the intervention can actually prevent the development of asthma.
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Spigt MG, Knipschild PG, van Schayck CP, Knottnerus JA. The validity and ethics of giving placebo in a randomized nonpharmacologic trial was evaluated. J Clin Epidemiol 2005; 58:350-6. [PMID: 15862720 DOI: 10.1016/j.jclinepi.2004.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2004] [Revised: 08/16/2004] [Accepted: 08/23/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVE When studying the effects of a non-pharmacologic intervention, the choice of a control group is often difficult. In a study on the effectiveness of increased water intake on voiding dysfunction in elderly men we used an unusual design. This article addresses the internal validty and ethics of this design. STUDY DESIGN AND SETTING The randomized trial we evaluated had a 6-month follow-up period and was carried out among 141 elderly men with moderate lower urinary tract symptoms. The experimental group was given the instruction to drink more water, the control group received placebo medication. The participants were not informed that there was a 50% chance of receiving placebo. We measured whether the prior expectations and preferences were comparable for the two study groups, whether blinding was preserved throughout the study period, and whether the participants considered this design ethical. RESULTS Prior to randomization, patients had higher expectations for the experimental intervention, but there was not statistically significant difference in their preference. During the study period, two out of 71 patients in the control group unmasked the placebo. In general, both groups fully agreed with the informed consent procedure. CONCLUSION This design can be considered when the effects of a non-pharmacologic interventions are studied.
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Knottnerus JA, Bos MA. ['Artificial support in case of hepatic failure'; a report from the Dutch Health Council]. NEDERLANDS TIJDSCHRIFT VOOR GENEESKUNDE 2005; 149:1302-3; author reply 1303. [PMID: 15960141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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Hopstaken RM, Stobberingh EE, Knottnerus JA, Muris JWM, Nelemans P, Rinkens PELM, Dinant GJ. Clinical items not helpful in differentiating viral from bacterial lower respiratory tract infections in general practice. J Clin Epidemiol 2005; 58:175-83. [PMID: 15680752 DOI: 10.1016/j.jclinepi.2004.08.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Incorrect and unnecessary antibiotic prescribing enhancing bacterial resistance rates might be reduced if viral and bacterial lower respiratory tract infections (LRTI) could be differentiated clinically. Whether this is possible is often doubted but has rarely been studied in general practice. STUDY DESIGN AND SETTING This was an observational cohort study in 15 general practice surgeries in the Netherlands. RESULTS Etiologic diagnoses were obtained in 112 of 234 patients with complete data (48%). Viral pathogens were found as often as bacterial pathogens. Haemophilus (para-) influenzae was most frequently found. None of the symptoms and signs correlated statistically significantly with viral or bacterial LRTI. Erythrocyte sedimentation rate >50 (odds ratio [OR] 2.3-3.3) and C-reactive protein (CRP) >20 (OR 2.1-4.6) were independent predictors for viral LRTI and bacterial LRTI when compared with microbiologically unexplained LRTI. CONCLUSION Extensive history-taking and physical examination did not provide items that predict viral or bacterial LRTI in adult patients in daily general practice. We could not confirm CRP to differentiate between viral and bacterial LRTI.
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Matthys J, De Meyere M, Mervielde I, Knottnerus JA, Den Hond E, Staessen JA, Duprez D, De Maeseneer J. Influence of the presence of doctors-in-training on the blood pressure of patients: a randomised controlled trial in 22 teaching practices. J Hum Hypertens 2005; 18:769-73. [PMID: 15141270 DOI: 10.1038/sj.jhh.1001744] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Until now, no information is available about the effect of the presence of a doctor-in-training on a patient's blood pressure. We tested the hypothesis that the presence of a last year medical student might increase the blood pressure of the patient, in addition to the possible pressor response to the doctor-trainer. Normotensive and hypertensive patients with a minimum age of 25 years, visiting for any reason, were recruited at 22 teaching general practices. Patients were randomised into a 'trainee' group (n=133) and a 'no trainee' (n=129) group. The blood pressure was measured at two subsequent contacts. In the 'trainee' group, a student was present at the first visit only. In the 'no trainee' group, both visits were without student. Both groups had similar anthropometric characteristics at entry. At the first visit, systolic pressure was higher in the 'trainee' group than in the control group (139.5 vs 133.1 mmHg, P=0.004), with a similar trend for diastolic pressure (80.2 vs 77.8 mmHg, P=0.07). From the first contact to the follow-up visit, blood pressure decreased in the trainee group by 4.8 mmHg systolic (P<0.001) and 1.7 mmHg diastolic (P=0.03), whereas the corresponding changes in the control group were -0.1 mmHg (P=0.90) and +1.5 mmHg (P=0.03). Thus, the between group differences in these trends averaging 4.7 mmHg (CI 1.5-7.9, P=0.005) systolic and 3.2 mmHg (CI 1.1-5.3, P=0.003) diastolic were statistically significant. We conclude that in teaching-practices, the presence of a doctor-in-training has a significant pressor effect when an experienced general practitioner measures a patient's blood pressure. If confirmed, our findings imply that doctors should be cautious to initiate or adjust antihypertensive treatment when blood pressure readings are obtained in the presence of a student.
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Schönberger HJ, Dompeling E, Knottnerus JA, Kuiper S, van Weel C, Schayck CP. Prenatal exposure to mite and pet allergens and total serum IgE at birth in high-risk children. Pediatr Allergy Immunol 2005; 16:27-31. [PMID: 15693908 DOI: 10.1111/j.1399-3038.2005.00243.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To examine the relationship between prenatal exposure to mite, cat and dog allergens and total serum IgE at birth in newborns at high risk of asthma. In the homes of 221 newborns with at least one first-degree relative with asthma, concentrations (ng/g dust) of allergens of house dust mite (mite), cat and dog were measured at the fourth to sixth month of pregnancy in dust samples from the maternal mattress and living room. At day 3-5 after birth, total IgE was measured in capillary heel blood. A total number of 174 blood samples were available (11 mothers refused newborn's blood sampling, and in 36 cases the blood sample was too small for analysis). In 24% of the newborns, total IgE was elevated (cut-off value 0.5 IU/ml). A significant dose response relationship was found between increasing mite allergen levels [divided in quartiles ng/g dust (qrt)] and the percentage of elevated IgE: first qrt (0-85 ng/g) 13%; second qrt (86-381) 19%; third qrt (382-2371) 26%; fourth qrt (> or =2372) 42%, respectively, p=0.01. This relationship remained significant after adjusting for passive smoking, maternal and paternal mite allergy, socio-demographic factors, birth characteristics and (breast) feeding practice in the first week of life. In high-risk newborns, prenatal exposure to mite allergens, but not to cat and dog allergens from dust of the living room and of the maternal mattress was associated with total serum IgE at birth.
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Schönberger HJAM, Maas T, Dompeling E, Knottnerus JA, van Weel C, van Schayck CP. Compliance of asthmatic families with a primary prevention programme of asthma and effectiveness of measures to reduce inhalant allergens--a randomized trial. Clin Exp Allergy 2004; 34:1024-31. [PMID: 15248845 DOI: 10.1111/j.1365-2222.2004.01991.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Compliance to and the effect of pre- and post-natal exposure reduction measures to prevent asthma in high-risk children from asthmatic families were studied. METHOD Families were randomized to a special care group (n=222) and a control group (n=221). Educational advice on measures to reduce their newborn's exposure to allergens and smoke was provided to the special care group during three visits (two pre-natal and one post-natal). The control group (n=221) received usual care. RESULT After the intervention, the special care group differed significantly (P<0.01) from the usual care group in: use of anti-mite encasings (parental: 88% vs. 14%; baby: 98% vs. 10%); keeping pets outside (51% vs. 19%); combined breast- and hypoallergenic formula feeding (55% vs. 22%); first solids postponement until after the sixth month (71% vs. 28%); maternal post-natal smoking (52% vs. 28%). Little or no compliance was found for other sanitary measures (cleaning habits, providing a smooth floor covering, ventilation/airing, pet removal), exclusive breastfeeding, pre-natal smoking and partner smoking. In spite of pre-existent low allergen levels in both groups, there was a significant reduction of mite, cat, and dog allergens on the mattresses and mite and cat allergens in the living room in the special care group and were significantly lower compared with the usual care group after 1 year. CONCLUSION High compliance was found for the use of anti-mite encasings; substantial compliance for using hypoallergenic formula, solid food postponement, keeping pets outside and reported post-natal maternal smoking. There was no compliance for sanitary measures and the reduction of maternal pre-natal passive smoking. Mite and pet allergens on mattresses were strongly reduced by anti-mite encasings.
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van Schayck CP, Knottnerus JA. Can the 'hygiene hypothesis' be explained by confounding by behavior? J Clin Epidemiol 2004; 57:435-7. [PMID: 15196612 DOI: 10.1016/j.jclinepi.2003.12.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2003] [Indexed: 11/29/2022]
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van Merode T, Twellaar M, Kotsopoulos IAW, Kessels AGH, Merckelbach H, de Krom MCTFM, Knottnerus JA. Psychological characteristics of patients with newly developed psychogenic seizures. J Neurol Neurosurg Psychiatry 2004; 75:1175-7. [PMID: 15258225 PMCID: PMC1739152 DOI: 10.1136/jnnp.2003.016923] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To assess psychopathological symptoms and history of childhood trauma in patients with newly developed psychogenic seizures. METHODS Using validated scales, 178 patients from the general population diagnosed with newly developed seizures were assessed, at a point in time when the nature of their seizures was yet unknown to either doctors or patients. After standardised neurological examination, 138 patients were diagnosed with non-psychogenic seizures (NPS), while 40 patients were found to have psychogenic seizures (PS). To evaluate possible differences between the genders and the diagnostic groups, univariate analyses of variance were done. RESULTS PS patients reported significantly more comorbid psychopathological complaints, dissociative experiences, anxiety, and self-reported childhood trauma than NPS patients. In addition, PS patients had lower quality of life ratings than NPS patients. These effects were not modulated by gender. CONCLUSIONS The results of the present study indicate that patients with newly developed PS constitute a group with complex psychopathological features that warrant early detection and treatment.
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Friesema IHM, Veenstra MY, Zwietering PJ, Knottnerus JA, Garretsen HFL, Lemmens PHHM. Measurement of lifetime alcohol intake: utility of a self-administered questionnaire. Am J Epidemiol 2004; 159:809-17. [PMID: 15051591 DOI: 10.1093/aje/kwh102] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Prior epidemiologic research revealing cardioprotective effects of alcohol intake has systematically neglected lifetime exposure to alcohol, which may cause serious bias in conclusions regarding drinking and heart disease risk. Departing from use of an earlier interview schedule, the authors of the present 1996-2001 cohort study developed a self-administered Lifetime Drinking History questionnaire (LDH-q). A total of 16,211 Dutch men and women older than age 45 years participated by completing the baseline questionnaire. A random sample of 3,255 men and women was used to determine the reliability and validity of the LDH-q. Test-retest reliability was assessed by means of the intraclass correlation coefficient and kappa scores. Correlations between lifetime and current intake scores were used to assess discriminant and convergent validity. Both reliability and validity appeared to be reasonably high compared with results obtained by using interview formats to measure lifetime alcohol intake. Reliability of the LDH-q was higher for men than for women, probably because of the more frequent and regular drinking of men. Indices of validity were similar for men (0.75) and women (0.70). Results show that the LDH-q can be a useful instrument in large-scale cohort studies.
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Spigt MG, van Schayck CP, van Kerrebroeck PE, van Mastrigt R, Knottnerus JA. Pathophysiological aspects of bladder dysfunction: a new hypothesis for the prevention of ‘prostatic’ symptoms. Med Hypotheses 2004; 62:448-52. [PMID: 14975521 DOI: 10.1016/j.mehy.2003.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Accepted: 10/26/2003] [Indexed: 11/20/2022]
Abstract
This article reviews the literature on the pathophysiology of male lower urinary tract symptoms (LUTS) with the intention of developing a new preventive intervention for this bothersome disease. Traditionally, male voiding dysfunction has been thought to arise from bladder outlet obstruction (BOO) caused by prostatic enlargement. Many years of research, however, have shown that a clear relationship between the size of the prostate and the occurrence or severity of symptoms is doubtful. Because of its crucial role in urination, it is increasingly being accepted that the clinical manifestation of voiding dysfunction relies on the functional behaviour of the bladder. Several animal studies have shown that bladder performance can be improved by increasing urine output. Contrary to alterations observed in pathologic situations, an increased urine output provides a physiologic stimulus for animal bladder function improvement. We hypothesise that a trained bladder should be less susceptible to the harmful effects of ageing and obstruction. Future symptoms may thus be prevented. In humans an increased urine output can be achieved by drinking additional water, which could be an adequate preventive intervention.
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Hooi JD, Kester ADM, Stoffers HEJH, Rinkens PELM, Knottnerus JA, van Ree JW. Asymptomatic peripheral arterial occlusive disease predicted cardiovascular morbidity and mortality in a 7-year follow-up study. J Clin Epidemiol 2004; 57:294-300. [PMID: 15066690 DOI: 10.1016/j.jclinepi.2003.09.003] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2003] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Asymptomatic peripheral arterial occlusive disease (PAOD) is a common atherosclerotic disorder among the elderly population. Scarce data are available on the risk of nonfatal and fatal cardiovascular diseases in these subjects. We investigated cardiovascular morbidity and mortality of asymptomatic PAOD subjects. STUDY DESIGN AND SETTING A sample of 3649 subjects (40-78 years of age) was selected in collaboration with 18 general practice centers and followed up after the initial screening (mean follow-up time 7.2 years). Asymptomatic PAOD was determined by means of the ankle-brachial pressure index (ABPI). Main outcome measures were nonfatal cardiovascular events and mortality. RESULTS Cox proportional hazard models showed that asymptomatic PAOD was significantly associated with cardiovascular morbidity (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.3-2.1), total mortality (HR 1.4, 95% CI 1.1-1.8), and cardiovascular mortality (HR 1.5, 95% CI 1.1-2.1). CONCLUSION Asymptomatic PAOD is a significant predictor of cardiovascular morbidity and mortality. In high-risk subjects, measurement of the ABPI provides valuable information on future cardiovascular events.
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Bijkerk CJ, Muris JWM, Knottnerus JA, Hoes AW, de Wit NJ. Systematic review: the role of different types of fibre in the treatment of irritable bowel syndrome. Aliment Pharmacol Ther 2004; 19:245-51. [PMID: 14984370 DOI: 10.1111/j.0269-2813.2004.01862.x] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Both high-fibre dietary advice and the prescription of fibre as a bulking agent are very common in primary and secondary care management of irritable bowel syndrome. Irritable bowel syndrome patients with constipation may have delayed intestinal transit. Therefore, fibres that accelerate intestinal transit may be beneficial in these patients. The uncertain benefits reported in several clinical studies, however, have led us to reappraise the value of fibre in irritable bowel syndrome management. AIM To quantify the effect of different types of fibre on global and symptom relief from irritable bowel syndrome. METHODS Using a structured literature search in MEDLINE (1966-2002), we selected randomized controlled trials involving irritable bowel syndrome patients treated with fibre. Analyses were performed for the total group and for trials using soluble and insoluble fibre separately. RESULTS Seventeen studies were included in the analysis. None investigated primary care irritable bowel syndrome patients. Fibre, in general, was effective in the relief of global irritable bowel syndrome symptoms [relative risk, 1.33; 95% confidence interval (CI), 1.19-1.50]. Irritable bowel syndrome patients with constipation may receive benefit from fibre treatment (relative risk, 1.56; 95% CI, 1.21-2.02), but there was no evidence that fibre was effective in the relief of abdominal pain in irritable bowel syndrome. Soluble and insoluble fibre, separately, had different effects on global irritable bowel syndrome symptoms. Soluble fibre (psyllium, ispaghula, calcium polycarbophil) showed significant improvement (relative risk, 1.55; 95% CI, 1.35-1.78), whereas insoluble fibre (corn, wheat bran), in some cases, worsened the clinical outcome, but there was no significant difference compared with placebo (relative risk, 0.89; 95% CI, 0.72-1.11). CONCLUSIONS The benefits of fibre in the treatment of irritable bowel syndrome are marginal for global irritable bowel syndrome symptom improvement and irritable bowel syndrome-related constipation. Soluble and insoluble fibres have different effects on global irritable bowel syndrome symptoms. Indeed, in some cases, insoluble fibres may worsen the clinical outcome. Future clinical studies evaluating the effect and tolerability of fibre therapy are needed in primary care.
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