dromlakhani Annually reassess use of SMBG to calibrate CGM
STEP 1 — Gather Information
Collect SMBG calibration frequency and timing, calibration log entries, sensor accuracy alerts, hypoglycemia/hyperglycemia events, patient-reported barriers (vision, dexterity, cognition), insurance coverage for strips, and current CGM model calibration requirements.
STEP 2 — Rule In / Rule Out
Is the patient performing SMBG calibration at least once per day (or per manufacturer’s recommendation) for the CGM system?
- Yes → Rule In: adequate calibration practice.
- No → Rule Out: inadequate calibration practice.
STEP 3 — Classify or Stratify
If Rule In: assess ability to make insulin adjustments based on CGM trend information (trend‑based dosing competence).
If Rule Out: classify barriers into cognitive/physical, insurance/access, or knowledge/behavioral deficits.
STEP 4 — Decide
- If Rule In and trend‑based dosing competent: continue current CGM use with annual reassessment.
- If Rule In but trend‑based dosing deficient: provide targeted education on interpreting CGM trends and adjusting insulin.
- If Rule Out: address specific barriers (e.g., simplify SMBG routine, assist with strip access, consider factory‑calibrated CGM if appropriate, reinforce calibration training).
Clinical Guardrails / Mimics / Pitfalls
Do not assume calibration adequacy without reviewing logs; do not rely solely on CGM for therapy decisions on devices requiring calibration; do not discontinue SMBG without confirming the CGM is factory‑calibrated; do not overlook sensor site irritation that may deter SMBG; avoid alarm fatigue by ensuring alerts are appropriately set.
Concrete Clinical Example
A 58‑year‑old with T1D using a Dexcom G6 (requires calibration) presents for yearly review. Log shows SMBG calibration twice weekly, missing daily calibrations. Patient reports finger‑stick pain and forgetfulness. After Rule Out, barriers classified as behavioral/physical. Decision: switch to a factory‑calibrated CGM (Freestyle Libre 3) and provide brief SMBG refresher for occasional confirmation.
Source: Diabetes Technology—Continuous Subcutaneous Insulin Infusion Therapy and Continuous Glucose Monitoring in Adults: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2016, DOI:10.1210/jc.2016-2534