Collaborative nurse-led self-management support for primary care patients with anxiety, depressive or somatic symptoms: Cluster-randomised controlled trial (findings of the SMADS study).
BACKGROUND
Collaborative, nurse-led care is a well-established model of ambulatory care in many healthcare systems. Nurses play a key role in managing patients' conditions as well as in enhancing symptom- and self-management skills.


OBJECTIVE
The SMADS trial evaluated the effectiveness of a primary care-based, nurse-led, complex intervention to promote self-management in patients with anxiety, depressive or somatic symptoms. Change in self-efficacy 12 months post baseline was used as the primary outcome.


METHODS
The SMADS trial set up a two-arm, cluster randomised controlled trial in the city of Hamburg, a large metropolitan area in the North West of Germany.


METHODS
We randomly allocated participating primary care practices to either the intervention group (IG), implementing a nurse-led collaborative care model, or to the control group (CG), where patients with the above psychosomatic symptoms received routine treatment.


METHODS
Patients from 18 to 65 years of age, regularly consulting a participating primary care practice, scoring≥5 on the anxiety, depressive or somatic symptom scales of the Patient Health Questionnaire (PHQ-D), German version.


METHODS
A mixed model regression approach was used to analyse the outcome data. Analyses were based on the intention-to-treat population: All enrolled patients were analysed at their follow-up. Additionally, we reported results as effect sizes. The robustness of the results was investigated by performing an observed cases analysis.


RESULTS
325 participants (IG N=134, CG N=191) from ten practices in each study arm consented to take part and completed a baseline assessment. The mean group difference (ITT-LOCF, IG vs. CG) in self-efficacy at the post baseline follow-up (median 406days) was 1.65 points (95% CI 0.50-2.8) in favour of IG (p=0.004). This amounts to a small Cohen's d effect size of 0.33. An observed cases analysis (168 participants, IG=56, CG=105) resulted in a mean difference of 3.13 (95% CI 1.07-5.18, p=0.003) between the groups, amounting to a moderate effect size of d=0.51.


CONCLUSIONS
A complex, nurse-led intervention, implemented as a collaborative care model, increased perceived self-efficacy in patients with symptoms of anxiety, depression or somatisation compare to control patients. For the first time in the German healthcare system, the SMADS trial validated the belief that a nurse can successfully complement the work of a general practitioner - particularly in supporting self-management of patients with psychosomatic symptoms and their psychosocial needs.
Department of General Practice / Primary Care, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: t.zimmermann@uke.de.
Thomas
T
Zimmermann
Department of General Practice / Primary Care, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: e.puschmann@uke.de.
Egina
E
Puschmann
Department of General Practice / Primary Care, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: bussche@uke.de.
Hendrik
H
van den Bussche
Institute for General Practice, Hannover Medical School, Carl-Neuberg-Str. 1, 30623 Hannover, Germany. Electronic address: wiese.birgitt@mh-hannover.de.
Birgitt
B
Wiese
Department of General Practice / Primary Care, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: a.ernst@uke.de.
Annette
A
Ernst
Department of General Practice / Primary Care, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: s.porzelt@uke.de.
Sarah
S
Porzelt
Department of Medical Biometry and Epidemiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: a.daubmann@uke.de.
Anne
A
Daubmann
Department of General Practice / Primary Care, Center for Psychosocial Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. Electronic address: m.scherer@uke.de.
Martin
M
Scherer
D000223:Adaptation, Psychological; D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care; D001007:Anxiety / Q000628:therapy*; D000066949:Biobehavioral Sciences; D003863:Depression / Q000628:therapy*; D005260:Female; D006801:Humans; D000070516:Intersectoral Collaboration; D008297:Male; D000071896:Medically Unexplained Symptoms; D008875:Middle Aged; D009739:Nursing Services / Q000706:statistics & numerical data; D011320:Primary Health Care; D011788:Quality of Life; D012044:Regression Analysis; D012648:Self Care / Q000379:methods*; D020377:Self Efficacy
Case management; Cluster-randomised; Collaborative care; Controlled trial; General practitioner; Nurse-led intervention; Primary care; Psychological disorders; Psychosomatic symptoms; Self-efficacy; Self-management support