title: Fluctuation of the renal function after discharge from hospital and its effects on drug dosing in elderly patients--study protocol.
abstract: BACKGROUND
  Chronic kidney disease (CKD) is associated with an increased mortality rate, risk of cardiovascular events and morbidity. Impaired renal function is common in elderly patients, and their glomerular filtration rate (GFR) should be taken into account when prescribing renally excreted drugs. In a hospital care setting the GFR may fluctuate substantially, so that the renal function group and therefore the recommended dose, can change within a few days. The magnitude and prevalence of the fluctuation of renal function in daily clinical practice and its potential effects on appropriateness of drug prescriptions after discharge from the hospital is unknown.
  
  
  METHODS
  This is a prospective observational study. Patients ≥ 70 years with renal impairment (eGFR < 60 ml/min/1.73 m(2)) admitted to a geriatric ward are eligible to participate. Participants undergo blood sample collection to measure serum creatinine level at three time points: at discharge from hospital, 14 days, and 2 months after discharge. At these time points the actual medication of the participants is assessed and the number of incorrect prescriptions according to the Dutch guidelines in relation to their estimated renal function is measured. In addition, for a hypothetical selection of drugs, the need for drug dose adaptation in relation to renal function is measured. The outcome of interest is the percentage of patients that changes from renal function group after discharge from hospital compared to the renal function at discharge. In addition, the percentages of patients whose actual medications are incorrectly prescribed and for the hypothetical selection of drugs that would have required dose adaptation will be determined at discharge, 14 days and 2 months after discharge. For each outcome, risk factors which may lead to increased risk for fluctuation of renal function and/or incorrect drug prescribing will also be identified and analysed.
  
  
  CONCLUSIONS
  This study will provide data on changes in renal function in elderly patients after discharge from the hospital with a focus on the medications used. The benefits for healthcare professionals comprise of the creation, adjustment or confirmation of recommendations for the monitoring of the renal function after discharge from hospital of elderly patients.
authors.affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, IQ healthcare, Postbus 9101, 114, 6500 HB, Nijmegen, The Netherlands. Willemijn.Eppenga@radboudumc.nl.
authors.forename: Willemijn L
authors.initials: WL
authors.lastname: Eppenga
authors.affiliation: Department of Geriatric Medicine, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands. wnwester@live.nl.
authors.forename: Wietske N
authors.initials: WN
authors.lastname: Wester
authors.affiliation: ZANOB, 's-Hertogenbosch, The Netherlands. J.Derijks@zanob.nl.|Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht Institute of Pharmaceutical Sciences, Utrecht, The Netherlands. J.Derijks@zanob.nl.
authors.forename: Hieronymus J
authors.initials: HJ
authors.lastname: Derijks
authors.affiliation: Laboratory of Clinical Chemistry and Haematology, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands. R.Hoedemakers@jbz.nl.
authors.forename: Rein M J
authors.initials: RM
authors.lastname: Hoedemakers
authors.affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, IQ healthcare, Postbus 9101, 114, 6500 HB, Nijmegen, The Netherlands. Michel.Wensing@radboudumc.nl.
authors.forename: Michel
authors.initials: M
authors.lastname: Wensing
authors.affiliation: Radboud University Medical Center, Radboud Institute for Health Sciences, IQ healthcare, Postbus 9101, 114, 6500 HB, Nijmegen, The Netherlands. pdesmet@knmp.nl.|Radboud University Medical Center, Department of Pharmacy, Nijmegen, The Netherlands. pdesmet@knmp.nl.
authors.forename: Peter A G M
authors.initials: PA
authors.lastname: De Smet
authors.affiliation: Department of Geriatric Medicine, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands. R.v.Marum@jbz.nl.|Department of General Practice and Elderly Care Medicine, VU University Medical Center Amsterdam, Amsterdam, The Netherlands. R.v.Marum@jbz.nl.
authors.forename: Rob J
authors.initials: RJ
authors.lastname: Van Marum
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000493:pharmacokinetics; D003404:Creatinine / Q000097:blood; D004232:Diuretics / Q000008:administration & dosage / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008297:Male; D009426:Netherlands; D010351:Patient Discharge; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D019338:Polypharmacy; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000378:metabolism; D012084:Renin-Angiotensin System
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004232:Diuretics; D004364:Pharmaceutical Preparations; D003404:Creatinine