Does depression predict the use of urgent and unscheduled care by people with long term conditions? A systematic review with meta-analysis.

Background: Factors that drive the use of urgent healthcare among people with chronic physical illness (i.e. long term conditions-LTCs) are poorly understood. We conducted a systematic review with meta analysis to examine the strength of association between depression and subsequent use of urgent healthcare among people with LTCs.

Methods: Electronic searches of MEDLINE, EMBASE, PSYCINFO, CINAHL, the British Nursing Library and the Cochrane Library 2011 were conducted, supplemented by hand-searching bibliographies, citation tracing eligible studies and asking experts about relevant studies. Studies were eligible for inclusion if they: i)used prospective cohort design, ii)included patients with diabetes, asthma, chronic obstructive pulmonary disease or coronary heart disease, iii)used a standardised measure of depression, and iv)assessed urgent healthcare utilisation prospectively. Data on the subjects recruited, methods used and the association between depression and subsequent urgent healthcare utilisation were extracted from eligible studies. Odds ratios (ORs) were calculated for each study and pooled using random effects models.

Results: 16 independent studies were identified. Pooled effects indicated that depression was associated with a 49% increase in the odds of urgent healthcare utilisation (OR=1.49, p<.0005). This effect was not significantly affected by publication bias or inclusion of studies of low quality. Effects were much smaller and non-significant among the 3 studies that controlled for other covariates, including severity of illness (OR=1.13, p=.31).

Conclusions: Depression was associated with increased urgent healthcare use, but not in the minority of studies that controlled for other covariates. This possibly suggests confounding, but the severity measures may themselves have been influenced by depression.