A Care Concept of Community Health Nursing Interventions for Adults With Chronic Health Conditions in an Urban Area: Protocol for a Randomized Controlled Field Trial (CoSta Study)

Background: Implementing community health nursing programs is a new field of application in the primary health sector of Germany. Hence, there is limited evidence of effective community-based and nurse-led interventions with regard to the German health care system. International research findings are mostly not transferable. The Community Health Nursing in der Stadt (CoSta; ie, "Community Health Nursing in the City") project is the first study that examines a community health nurse-led intervention for adults with chronic health conditions.

Objective: This study protocol describes the design and methods of a randomized controlled field trial that will investigate if a community health nurse-based intervention has an impact on health-related quality of life in adults with chronic conditions.

Methods: The study was designed as a randomized controlled trial that will be conducted under real-life conditions in the field. In a 4-month period, patients with at least 1 chronic International Classification of Diseases, Tenth Revision, diagnosis will be enrolled. Participants will be randomly allocated to an intervention group or a control group. The sample size was assumed based on an effect size of 0.50 with a significance level of .05, using a 2-sided (2-tailed), 2-sample unequal variance t test. The control group will be treated as usual. The intervention group will receive-in addition to the usual treatment-preventive home visits; consultations; and educative training, which will be offered by 2 community health nurses for up to 12 months. Both groups will be followed up at baseline, after 6 months, and after 12 months. The primary outcome measure is the mental component summary score from the 36-Item Short Form Health Survey after 12-months. Secondary patient outcomes will be included. The study received ethics approval from the Competence Health Center's institutional review board at the University of Applied Sciences Hamburg (procedure number: 2020-14).

Results: The CoSta project was funded by the Federal Ministry of Education and Research Germany (contract number: 13FH019SX8). In total, 187 participants were recruited at the beginning of August 2021. Further, 92 were excluded and 94 were randomized. Data collection will be conducted until the end of 2022.

Conclusions: Our study will provide data with regard to the effectiveness of community nurse-led interventions that focus on the treatment of vulnerable adults with chronic health conditions in a community health center. In secondary analyses, the associations among influencing social factors (education, income, and employment) will be examined. We expect results that will help reduce the research-to-practice gap.

Trial registration: German Clinical Trials Register DRKS00026164; https://tinyurl.com/yckxc5ut.

International registered report identifier (irrid): DERR1-10.2196/37965.

Keywords: Germany; adults; chronic health conditions; community health nursing; community-based program; health-related quality of life; intervention; nurse; nurse-led consultation; nursing; protocol; randomized controlled trial; urban.