The relationship between headache-attributed disability and lost productivity: 2. Empirical evidence from population-based studies in nine disparate countries

Table 10 Linear regressions between headache-attributed disability¹ and lost paid worktime attributed to probable medication-overuse headache by country

Country	HALT question 1 (absenteeism)			HALT question 2 (presenteeism)			HALT questions 1 + 2 (total lost paid worktime)
Country	R²	Equation	p	R²	Equation	p	R²	Equation	p
Ethiopia	0.06	Y = 0.60x + 0.7	0.28	0.00	Y = 0.01x + 8.4	0.98	0.02	Y = 0.61x + 9.1	0.48
India	0.00	Y = -0.09x + 3.6	0.77	0.15	Y = 0.23x – 0.6	0.05	0.01	Y = 0.14x + 3.0	0.70
Lithuania + Luxembourg	0.00	Y = -0.04x + 2.0	0.81	0.04	Y = 0.27x + 3.2	0.16	0.02	Y = 0.25x + 4.9	0.37
Nepal	0.02	Y = 0.23x + 3.1	0.28	0.03	Y = 0.16x + 1.8	0.23	0.03	Y = 0.39x + 4.9	0.23
Pakistan	0.08	Y = -0.18x + 5.7	0.006	0.15	Y = -0.25x + 7.0	< 0.001	0.13	Y = -0.43x + 12.5	< 0.001
Russia	0.04	Y = 0.14x – 0.05	0.11	0.00	Y = 0.03x + 3.6	0.81	0.02	Y = 0.16x + 3.5	0.31
Spain	0.01	Y = 0.19x + 3.6	0.64	0.04	Y = 0.47x + 8.0	0.19	0.03	Y = 0.53x + 11.1	0.28

HALT: Headache-Attributed Lost Time questionnaire. ¹ Calculated as proportion of time in ictal state*disability weight from GBD2015 [49]; significant p-values are emboldened.

ISSN: 1129-2377