The question this study addressed. This direct observation study at the Mimboman Health Centre analyzes technical compliance during 50 actual tests. It breaks down every step, from capillary puncture to final interpretation and waste disposal. What the study adds to our knowledge. The study quantifies an alarming error burden: 275 mistakes for only 50 tests. The major finding is the massive concentration of failures (72%) during the analytical phase, particularly a near-systematic failure to respect reading times (80%). It reveals that the absence of on-site written protocols (98%) is the primary driver of these errors, far more than individual incompetence. This publication is available in full in Health Sciences and Disease.