Table 3. Incidence of Severe Acute Malnutrition as per Ethiopian operational definition and protocols (MUAC <11cm or bilateral pitting oedema).

Stratification by MUAC at enrolment	N	No. of episodes	Follow-up time (100 months)†	Incidence rate (95% CI) per 100 person-months‡	Incidence rate ratio (95% CI)
All children	884	82	52.3	1.57 (1.26–1.94)
12.0 - <12.5 cm	558	18	34.7	0.52 (0.32–0.80)	1.0
11.5 - <12.0 cm	215	25	12.6	1.99 (1.32–2.89)	3.8 (2.0–7.4)
11.0 - <11.5 cm	111	39	5.03	7.75 (5.59–10.5)	14.9 (8.3–27.7)

† Total time at risk, expressed in units of 100 person-months.

‡ Incidence of first episode of SAM, expressed per 100 person-months.

Abbreviations: MUAC, mid-upper arm circumference; CI, confidence interval.