Multimorbidity patterns: a systematic review.
OBJECTIVE
The aim of this review was to identify studies on patterns of associative multimorbidity, defined as the nonrandom association between diseases, focusing on the main methodological features of the studies and the similarities among the detected patterns.


METHODS
Studies were identified through MEDLINE and EMBASE electronic database searches from their inception to June 2012 and bibliographies.


RESULTS
The final 14 articles exhibited methodological heterogeneity in terms of the sample size, age and recruitment of study participants, the data source, the number of baseline diseases considered, and the statistical procedure used. A total of 97 patterns composed of two or more diseases were identified. Among these, 63 patterns were composed of three or more diseases. Despite the methodological variability among studies, this review demonstrated relevant similarities for three groups of patterns. The first one comprised a combination of cardiovascular and metabolic diseases, the second one was related with mental health problems, and the third one with musculoskeletal disorders.


CONCLUSIONS
The existence of associations beyond chance among the different diseases that comprise these patterns should be considered with the aim of directing future lines of research that measure their intensity, clarify their nature, and highlight the possible causal underlying mechanisms.
EpiChron Research Group on Chronic Diseases, Aragón Health Sciences Institute (IACS), IIS Aragón, Miguel Servet University Hospital, Pl +2, Paseo Isabel la Católica 1-3, 50009, Zaragoza, Spain; Department of Microbiology, Preventive Medicine and Public Health, University of Zaragoza, Facultad de Medicina, C/ Domingo Miral s/n, 50009, Zaragoza, Spain; Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Carlos III Health Institute, Madrid, Spain; Teaching Unit of Preventive Medicine and Public Health, Aragón Health Sciences Institute (IACS), IIS Aragón, Edificio CIBA, Avda. San Juan Bosco 13, 50009, Zaragoza, Spain. Electronic address: sprados.iacs@aragon.es.
Alexandra
A
Prados-Torres
EpiChron Research Group on Chronic Diseases, Aragón Health Sciences Institute (IACS), IIS Aragón, Miguel Servet University Hospital, Pl +2, Paseo Isabel la Católica 1-3, 50009, Zaragoza, Spain; Department of Microbiology, Preventive Medicine and Public Health, University of Zaragoza, Facultad de Medicina, C/ Domingo Miral s/n, 50009, Zaragoza, Spain; Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Carlos III Health Institute, Madrid, Spain; Teaching Unit of Preventive Medicine and Public Health, Aragón Health Sciences Institute (IACS), IIS Aragón, Edificio CIBA, Avda. San Juan Bosco 13, 50009, Zaragoza, Spain.
Amaia
A
Calderón-Larrañaga
Teaching Unit of Preventive Medicine and Public Health, Aragón Health Sciences Institute (IACS), IIS Aragón, Edificio CIBA, Avda. San Juan Bosco 13, 50009, Zaragoza, Spain.
Jorge
J
Hancco-Saavedra
EpiChron Research Group on Chronic Diseases, Aragón Health Sciences Institute (IACS), IIS Aragón, Miguel Servet University Hospital, Pl +2, Paseo Isabel la Católica 1-3, 50009, Zaragoza, Spain; Teaching Unit of Preventive Medicine and Public Health, Aragón Health Sciences Institute (IACS), IIS Aragón, Edificio CIBA, Avda. San Juan Bosco 13, 50009, Zaragoza, Spain.
Beatriz
B
Poblador-Plou
CAPHRI School for Public Health and Primary Care, Maastricht University, P Debijeplein 1, PO Box 616, 6200 MD, Maastricht, The Netherlands; Department of General Practice, Katholieke Universiteit Leuven, Oude Markt 13 - box 5005, 3000, Leuven, Belgium.
Marjan
M
van den Akker
D002908:Chronic Disease / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D012107:Research Design
Associative multimorbidity; Chronic disease; Electronic medical records; Patient-centered care; Practice guidelines; Primary health care