Polypharmacy and specific comorbidities in university primary care settings.
OBJECTIVE
Polypharmacy is associated with adverse events and multimorbidity, but data are limited on its association with specific comorbidities in primary care settings. We measured the prevalence of polypharmacy and inappropriate prescribing, and assessed the association of polypharmacy with specific comorbidities.


METHODS
We did a cross-sectional analysis of 1002 patients aged 50-80years followed in Swiss university primary care settings. We defined polypharmacy as ≥5 long-term prescribed drugs and multimorbidity as ≥2 comorbidities. We used logistic mixed-effects regression to assess the association of polypharmacy with the number of comorbidities, multimorbidity, specific sets of comorbidities, potentially inappropriate prescribing (PIP) and potential prescribing omission (PPO). We used multilevel mixed-effects Poisson regression to assess the association of the number of drugs with the same parameters.


RESULTS
Patients (mean age 63.5years, 67.5% ≥2 comorbidities, 37.0% ≥5 drugs) had a mean of 3.9 (range 0-17) drugs. Age, BMI, multimorbidity, hypertension, diabetes mellitus, chronic kidney disease, and cardiovascular diseases were independently associated with polypharmacy. The association was particularly strong for hypertension (OR 8.49, 95%CI 5.25-13.73), multimorbidity (OR 6.14, 95%CI 4.16-9.08), and oldest age (75-80years: OR 4.73, 95%CI 2.46-9.10 vs.50-54years). The prevalence of PPO was 32.2% and PIP was more frequent among participants with polypharmacy (9.3% vs. 3.2%, p<0.006).


CONCLUSIONS
Polypharmacy is common in university primary care settings, is strongly associated with hypertension, diabetes mellitus, chronic kidney disease and cardiovascular diseases, and increases potentially inappropriate prescribing. Multimorbid patients should be included in further trials for developing adapted guidelines and avoiding inappropriate prescribing.
Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland. Electronic address: caroleelodie.aubert@insel.ch.
Carole E
CE
Aubert
Institute of Primary Health Care BIHAM, University of Bern, Switzerland. Electronic address: sven.streit@biham.unibe.ch.
Sven
S
Streit
Institute of Primary Health Care BIHAM, University of Bern, Switzerland. Electronic address: bruno.dacosta@biham.unibe.ch.
Bruno R
BR
Da Costa
Service of Endocrinology, Diabetes and Metabolism, University Hospital of Lausanne, Switzerland; University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK. Electronic address: tinh-hai.collet@chuv.ch.
Tinh-Hai
TH
Collet
Department of Ambulatory Care and Community Medicine, University of Lausanne, Switzerland. Electronic address: jacques.cornuz@chuv.ch.
Jacques
J
Cornuz
Department of Community and General Medicine, Geneva University Hospital, Geneva, Switzerland. Electronic address: jean-michel.gaspoz@hcuge.ch.
Jean-Michel
JM
Gaspoz
Departments of Medicine and Epidemiology and Biostatistics, University of California, San Francisco, United States. Electronic address: dbauer@psg.ucsf.edu.
Doug
D
Bauer
Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland. Electronic address: drahomir.aujesky@insel.ch.
Drahomir
D
Aujesky
Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Switzerland; Institute of Primary Health Care BIHAM, University of Bern, Switzerland. Electronic address: nicolas.rodondi@insel.ch.
Nicolas
N
Rodondi
D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000188:drug therapy; D015897:Comorbidity; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D003920:Diabetes Mellitus / Q000188:drug therapy; D005260:Female; D006785:Hospitals, University; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D057970:Inappropriate Prescribing / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D019338:Polypharmacy; D011320:Primary Health Care; D051436:Renal Insufficiency, Chronic / Q000188:drug therapy; D013557:Switzerland
Comorbidities; Inappropriate prescribing; Multimorbidity; Pharmacoepidemiology; Polypharmacy