International Multicenter Validation Study of the SAGIT® Instrument in Acromegaly

J Clin Endocrinol Metab. 2021 Nov 19;106(12):3555-3568. doi: 10.1210/clinem/dgab536.

Abstract

Context: The SAGIT® instrument (SAGIT) has been developed to enable accurate characterization of acromegaly disease activity.

Objective: We evaluated the ability of SAGIT to discriminate acromegaly disease control status.

Methods: This multicenter, noninterventional, prospective and retrospective, longitudinal study, conducted at academic and private clinical practice sites, included patients aged ≥ 18 years with a diagnosis of controlled (n = 109) or non-controlled (n = 105) acromegaly, assessed by clinical global evaluation of disease control (CGE-DC) questionnaire, investigator therapeutic decision, and international guidelines. Control status was not determined at baseline for 13 patients. Since 9 patients were enrolled retrospectively, all presented analyses are based on the prospective population (N = 227). Patients were assessed over a 2-year follow-up period. Classification and regression tree (CART) analyses were performed to investigate how SAGIT components at baseline (signs/symptoms [S], associated comorbidities [A], growth hormone levels [G], insulin-like growth factor 1 levels [I], tumor features [T]) discriminate between controlled and non-controlled acromegaly.

Results: Baseline mean subscores S, G, I, and T were significantly lower in patients with CGE-DC controlled vs CGE-DC non-controlled acromegaly. SAGIT components I and G for CGE-DC and S, A, G, I, and T for the clinician's therapeutic decision were retained by CART analyses. For international guidelines, only SAGIT component I was retained. The risk for undergoing ≥ 1 treatment change during the study was 3.44 times greater for CGE-DC non-controlled acromegaly relative to CGE-DC controlled acromegaly.

Conclusion: The SAGIT instrument is a valid and sensitive tool to comprehensively and accurately assess acromegaly severity.

Trial registration: ClinicalTrials.gov NCT02539927.

Keywords: SAGIT® instrument; acromegaly control; acromegaly management; clinician-reported outcomes.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Acromegaly / blood
  • Acromegaly / diagnosis*
  • Biomarkers / blood*
  • Case-Control Studies
  • Diagnostic Tests, Routine / instrumentation*
  • Diagnostic Tests, Routine / methods
  • Female
  • Follow-Up Studies
  • Human Growth Hormone / blood*
  • Humans
  • Insulin-Like Growth Factor I / analysis*
  • International Agencies
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Prognosis
  • Prospective Studies
  • ROC Curve
  • Retrospective Studies

Substances

  • Biomarkers
  • IGF1 protein, human
  • Human Growth Hormone
  • Insulin-Like Growth Factor I

Associated data

  • ClinicalTrials.gov/NCT02539927