Table 3.

Negative binomial regressions for severe, non-severe, any, and nocturnal hypoglycemic events

	IRR (95% CI)	p-value
Severe hypoglycemic eventsa
Age (years)	0.98 (0.97–0.99)	0.001
Gender: female [ref. male]	1.67 (1.01–2.77)	0.047
Duration of diabetes (years)	1.03 (1.01–1.05)	0.001
Fear of hypoglycemia (scale 1–10)	1.17 (1.06–1.29)	0.002
Period: prospective [ref. retrospective]	4.75 (2.75–8.23)	< 0.001
Non-severe hypoglycemic eventsa
Duration of insulin therapy (years)	1.02 (1.01–1.03)	0.003
Diabetes type: T1DM [ref. T2DM]	2.59 (1.99–3.38)	< 0.001
Frequency of blood glucose monitoring (days)	1.14 (1.07–1.20)	< 0.001
Period: prospective [ref. retrospective]	1.81 (1.53–2.14)	< 0.001
Any hypoglycemic eventsa
Duration of insulin therapy (years)	1.02 (1.01–1.03)	< 0.001
Diabetes type: T1DM [ref. T2DM]	2.34 (1.81–3.03)	< 0.001
Frequency of blood glucose monitoring (days)	1.13 (1.06–1.20)	< 0.001
Period: prospective [ref. retrospective]	2.05 (1.76–2.39)	< 0.001
Nocturnal hypoglycemic eventsa
Diabetes type: T1DM [ref. T2DM]	2.06 (1.46–2.90)	< 0.001
Frequency of blood glucose monitoring (days)	1.12 (1.05–1.20)	0.001
Hypoglycemia awareness: impaired or severely impaired [ref. normal]	0.65 (0.46–0.91)	0.012

* Negative binomial regression model (after stepwise) Subject effect: Patient; Within-subject effect: Period; Offset variable: Ln (follow-up time); Dependent variable: number of hypoglycemic events. Independent variables: age, gender, HbA1c, diabetes type, duration of diabetes, duration of insulin therapy, type of insulin therapy, frequency of blood glucose monitoring, knowledge of hypoglycemia, hypoglycemia unawareness, fear of hypoglycemia and period

IRR incidence rate ratio, CI confidence interval. Ref. reference category versus the one is making comparison (categorical variables); for continuous variables, please consider IRR per additional unit