The ageing process is characterized by a high level of complexity, due to theco-occurrence of multiple chronic diseases (comorbidity) that often resultsin the concomitant use of multiple drug therapies (polypharmacy) fortreatment and prophylaxis. Institutionalized elderly may be regarded as theparadigm of this complexity because of their multiple chronic diseases anddecreased functional and cognitive functions.

To explore and characterize the prevalence of comorbidity and polypharmacy ina sample of institutionalized elderly.

A cross-sectional study was conducted with an elderly sample recruited fromthree Portuguese nursing homes. Clinical information was obtained throughinterview and by review of residents’ medical records. The AnatomicalTherapeutic Chemical/ATC classification was used to indicate the main groupof medicines used, and polypharmacy was categorized into minor (2–4medicines) or major (≥ 5). Comorbidities were coded using theindividual body systems of Cumulative Illness Rating Scale forGeriatrics/CIRS-G.

The sample included 175 elderly with a mean age of 81 (sd = 10) years andinstitutionalized for an average of 7 (sd = 11) years. Residents presented amean of 9 (sd = 4) co-morbid medical conditions, mostly psychiatric (80.8%),vascular (76.7%) and endocrine/metabolic (70.3%). Major polypharmacy wasverified for 73.9% of residents. The mean number of medicines was 7 (sd =3), most commonly for cardiovascular (86.0%) and nervous system (79.1%) andfor blood and blood-forming organs (69.2%).

As in other studies in similar settings, polypharmacy was fairly common.These results convey an important message considering that polypharmacy hasbeen associated with negative clinical outcomes that could otherwise bepreventable by reducing the number of prescribed medicines.

The authors have not supplied their declaration of competing interest.