NCT06762275: ISAAK

The Impact of a Diagnostic Strategy for Acute Appendicitis in Children With Acute Abdominal Pain in Primary Care

Recruiting now NA Last updated 26 November 2025

What this trial tests

NA trial testing Diagnostic strategy in Appendicitis Acute in 566 participants. Currently enrolling.

Timeline

6 March 2025

Primary endpoint
31 March 2028

1 March 2029

Quick facts

Lead sponsor	University Medical Center Groningen
Phase	NA
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	diagnostic
Enrollment	566
Start date	6 March 2025
Primary completion	31 March 2028
Estimated completion	1 March 2029
Sites	1 location across Netherlands

Drugs / interventions tested

• Diagnostic strategy

Conditions studied

• Appendicitis Acute — all drugs for Appendicitis Acute →
• Acute Abdomen in Children — all drugs for Acute Abdomen in Children →

Sponsor

University Medical Center Groningen

Who can join

Adults 4 to 18, any sex, with Appendicitis Acute or Acute Abdomen in Children. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

BACKGROUND Acute appendicitis (AA) in an early stage is difficult to distinguish from other (self-limiting) causes of acute abdominal pain (e.g. constipation and gastroenteritis), resulting in missing 19% of children with AA at first presentation in primary care and 70% of non-AA cases among referrals.

OBJECTIVE To evaluate the impact of the use of a diagnostic strategy for acute appendicitis (AA), which consists of a clinical prediction rule (cPR) including C-reactive protein point-of-care test (CRP POCT), on referral efficiency in children with acute abdominal pain in primary care, as compared to usual care.

STUDY DESIGN This is a cluster randomized controlled trial in primary care with a process evaluation. GPs in the intervention group will use an externally validated cPR based on symptoms and signs selectively followed by a CRP POCT in the medium risk group. GPs from general practices allocated to the control group will provide care and diagnosis as usual, i.e. following recommendations of the Dutch College of GPs guideline 'abdominal pain in children'.

STUDY POPULATION Children aged 4 to 18 years presenting to their general practitioner (GP) with acute abdominal pain.

OUTCOME MEASURES Primary outcome: referral efficiency (proportion non-referrals in non-AA patients during 30 days follow-up).

Secondary outcomes: safety (proportion of referrals in AA patients during the first consultation), proportion of children with CRP-POCT, proportion of children with planned reassessment, child anxiety, parent or child satisfaction, quality of life, and costs.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Methods for Evaluating Models, Tests And Biomarkers (MEMTAB): Abstracts from the 7<sup>th</sup> International Conference, MEMTAB 2025.
   · 2026 · PMID 42169161 · DOI 10.1186/s41512-026-00227-w