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Useful and cost-effective workup in chronic polyneuropathy


Zinnige diagnostiek bij polyneuropathie
Polyneuropathie is een veel voor komende neurologische aandoening. In Nederland hebben meer dan 300.000 mensen polyneuropathie en er zijn veel verschillende oorzaken voor deze ziekte. Het vinden van de oorzaak is belangrijk voor de behandelingsmogelijkheden. De Nederlandse Richtlijn Polyneuropathie 2019 geeft aanbevelingen voor het verrichten van uitgebreid bloedonderzoek en zenuwonderzoek (EMG).
Dit is een zorgevaluatieonderzoek bij 1200 volwassen poliklinische patiënten om vast te stellen welke bloedonderzoeken zinnig zijn en wanneer EMG-onderzoek moet plaats vinden voor het stellen van de juiste diagnose.
De zorgevaluatie vergelijkt de aanpak van standaard diagnostiek met de aangepaste methode van beperkt onderzoek om te bepalen of de juiste diagnose gesteld kan worden. Daarnaast vindt evaluatie plaats van medische zorg- en patiëntgerelateerde kosten, invloed op behandeling en beleid, en belasting en voordelen voor de patiënt.


Dit onderzoek sluit aan op de kennisagenda Neurologie


Bekijk de bijbehorende richtlijnen in de FMS Richtlijnendatabase Laboratoriumonderzoek zonder alarmsymptomen bij polyneuropathie, Stroomdiagram diagnostiek polyneuropathie en Indicatie EMG bij polyneuropathie

Inclusiemonitor - Voortgang deelnemende patiënten

Bekijk de voortgang van het aantal deelnemende patiënten (inclusies) aan deze studie.


Samenvatting van de aanvraag

OBJECTIVE(S)/RESEARCH QUESTION(S) This project is a quality in health care evaluation to ascertain if and which blood tests and when nerve conduction study (NCS) are necessary and cost-effective to establish the diagnosis and identify the cause of polyneuropathy, a disease that affects over 300.000 persons in the Netherlands. HYPOTHESIS In many patients with a clinical diagnosis of chronic polyneuropathy, a limited or no workup (blood tests, NCS) improves cost-effectiveness without loss of diagnostic reliability, and a clinical prediction tool can reliably aid clinical decision-making when NCS is necessary and useful to distinguish a treatable inflammatory demyelinating polyneuropathy from chronic axonal polyneuropathy. PATIENT (P) Adult patients at least 18 years old with suspected polyneuropathy referred to a neurologist for diagnosis confirmation and establish the cause. INTERVENTION (I) Limited or no further workup by consensus of a panel experienced neurologists. Only the components of the workup as indicated by the panel are used to reach a diagnosis and only these are taken into account in the cost-effectiveness evaluation. The panel is blinded for the actually performed workup and established diagnosis by patients' neurologists. To aid more objective decision-making, the developed clinical prediction tool will be applied by the panel for validation. COMPARATOR (C) Standard workup and diagnosis made by patients' neurologists. This is directed by the Dutch Guideline Polyneuropathy 2019 and is expected to consists of at least the guideline recommended (extensive) investigations. OUTCOME (O) Primary outcome is effectiveness of a limited or no further workup expressed as concordance between panel diagnosis and patients’ neurologists diagnosis (i.e. percentage overlooked diagnoses). This will be related to differences in costs and impact on treatment or patient management otherwise. Other outcomes are burden/gain for the patient in terms of number of investigations, time to diagnosis, hospital visits, sick-leave, loss of productivity, expenses, experienced quality of care. FOLLOW-UP TIME Six months. STUDY DESIGN Prospective observational multi-centre study carried out in four large general hospitals and three neuromuscular expertise centres. Patients are identified through screening of referral letters and the patients' electronic medical records (EMR) are used to gather all relevant data pertaining to the workup of polyneuropathy and the outcome measures. Direct medical costs and other health care costs are determined from these data and questionnaires, as well as time to diagnosis. The workup and diagnosis by patients’ neurologists are compared to those indicated by the panel. SAMPLE SIZE CALCULATION/DATA ANALYSIS Total sample size will be 1,200 patients. The primary outcome is to show that a limited or no further workup does not result in more than 5% overlooked diagnoses. Assuming 0.7 correlation between intervention and comparator workup, standard sample size calculations show that 500 paired observations are needed to detect a 5% or more difference in diagnostic concordance (90% power, two-sided alpha 5%). Classical measures of test-retest reliability and for comparison of paired observations will be used to estimate the correlation and differences between the standard workup and limited or no further workup. Regarding the clinical prediction tool, it is assumed that 10-12.5% of referred patients have a treatable inflammatory demyelinating polyneuropathy. Considering that at least 20 events per predictive variable (5 in total) are needed, 1000 patients referred with suspected polyneuropathy would be required. An additional 200 patients (20%) will be enrolled as validation cohort.The predefined diagnostic elements will be used in a logistic regression model. Models will be internally validated by bootstrapping, external validation by applying the model to the last 200 patients. Model performance is evaluated in terms of discrimination, calibrations slopes and prediction error. COST-EFFECTIVENESS ANALYSIS/BUDGET IMPACT ANALYSIS We will perform an economic evaluation from a societal perspective with a 6 months' time horizon and relate patient outcomes and diagnosis to average cost per patient. A budget impact analysis will be performed to assess total impact on Dutch health care budget. TIME SCHEDULE Total project duration is 4 years: -Oct2020-Jun2021 (9 months): pre-study survey (patient participation); prepare study protocol & METC approval; set up electronic database; procure permissions in participating centres;. -Jul2021-Jun2023 (24 months): patient inclusion & follow-up; start data collection/input; panel reviews. -Jul2023-Dec2023 (6 months): complete follow-up; continued panel reviews & data collection/input. -Jan2024-Sept2024 (9 months): finalize panel reviews & data collection/input; data analysis; prepare study report & systematic review.


Looptijd: 81%
Looptijd: 81 %
Gerelateerde subsidieronde:
Projectleider en penvoerder:
dr. A.F.J.E. Vrancken
Verantwoordelijke organisatie:
Universitair Medisch Centrum Utrecht