Background In the context of population ageing, polypharmacy is strongly associated with multimorbidity. Studies have revealed the existence of multimorbidity patterns. No studies have evaluated whether the complexity of the medicines regimen varies with the multimorbidity patterns.

Purpose To analyse the extent to which treatment complexity differs between multimorbidity patterns in the older population.

Material and methods We conducted a retrospective observational study. We included patients ≥65 years with more than one chronic condition (according to the Quality and outcomes framework database) and with criteria of polypharmacy (>5 medicines/day) who were admitted to an internal medical unit between September/October 2014. Patients who were assigned to more than one multimorbidity pattern were excluded. Variables collected were: demographic, multimorbidity pattern, number of chronic conditions and chronic medicines, and the medicines regimen complexity index (MRCI). Multimorbidity patterns were identified as cardiometabolic, mechanical and psychogeriatric.¹ MRCI was calculated using a 65-item tool² which comprised the dosage forms, the dosing frequencies and additional directions. Student’s T test was applied to compare MRCI in the multimorbidity patterns using SPSS-20.

Results 51 patients (52.9% male) were included. 15 (29.4%) aged 65–74 years, 29 (56.9%) 75–84 and 7 (13.7%) >85 years. The average number of diseases and medicines were 5.6 ± 2.5 and 10.5 ± 4.0, respectively. The average MRCI was 32.5 ± 15.2. The most decisive factor contributing to the complexity was the dosing frequency (13.7 ± 6.8), followed by the dosage form (12.7 ± 5.5) and the additional directions (6.0 ± 4.3). 31 (60.8%) patients were assigned to a cardiometabolic pattern (5.8 ± 2.8 diseases, 11.2 ± 3.9 medicines, 35.3 ± 15.7 MRCI); 13 (25.5%) patients presented a mechanical pattern (5.4 ± 2.25 diseases, 10.2 ± 4.7 medicines, 30.9 ± 16.4 MRCI) and 7 (13.7%) were assigned a psychogeriatric pattern (5.1 ± 1.6 diseases, 8 ± 1.3 medicines, 23.5 ± 4.8 MRCI). There were no significant differences between the MRCI in the patterns of multimorbidity.

Conclusion Treatment complexity does not differ between multimorbidity patterns in the older population.

References and/or Acknowledgements

1. Prados-Torres A, Poblador-Plou B, Calderón-Larrañaga A, et al. Correction: multimorbidity patterns in primary care: interactions among chronic diseases using factor analysis. PLoS One 2012;7(2):e32190

2. George J, Phun YT, Bailey MJ, et al. Development and validation of the medication regimen complexity index. Ann Pharmacother 2004;38:1369–76

References and/or AcknowledgementsNo conflict of interest.