Page 56 - The clinical aspects and management of chronic migraine Judith Anne Pijpers

Chapter 3
Table 1. Baseline characteristics of patients with medication overuse headache, included for primary analysis, without (group A) and with (group B) support by a headache nurse (n = 416).
Gender, % female
Age at time of diagnosis
Headache days % daily
median (interquartile)
Medication Analgesics only
Triptans only Analgesics + triptans Other medication
Caffeine units/day
Medication days % daily
median (interquartile)
A. No headache nurse (n=163)
102 (63%) 47.5 ± 10.7
B. Headache nurse (n=253)
196 (78%) 44.4 ± 14.6
151 (60%)
30.4 (19.1-30.4)
126 (50%) 13 (5%) 93 (37%) 21 (8%)
5.3 ± 3.6
95 (38%)
20 (14.3-30.4)
p
0.001a 0.014b
0.60a 0.41c
0.040a
0.55b
0.14a 0.37c
93 30.4
83 20 51 9
(57%) (17.4-30.4)
(51%) (12%) (31%) (6%)
5.7 ± 4.2
73 (45%)
21.7 (15.0-30.4)
54
Values are the absolute numbers with corresponding % or means ± SD. Significant p values are depicted in bold. a χ2 test
b Two-tailed independent samples t-test c Independent Samples Mann-Whitney U test
Effectiveness of support by a headache nurse in successful withdrawal in MOH
As shown in Table 2, the percentage of patients with successful withdrawal was significantly higher in the group with support of the headache nurse than the group without support (73.1% vs. 60.7%, p = 0.008, Absolute risk reduction = 12.4%, Number Needed to Treat = 8). As a consequence of the instructions at the first visit (not to come for a second visit if withdrawal was not successful) a larger proportion of patients of group A did not visit for a second time, and were lost to follow up (27.0% vs. 12.3%). However, the results were similar when lost to follow-up patients were analysed as a separate group. The support by a headache nurse was significantly associated with the odds for successful withdrawal in multivariate regression (Odds Ratio [OR] 1.73; 95% CI, 1.11 – 2.71; p=0.016)(Table 3), indicating that the support by a headache nurse enhances successful withdrawal, independent of age, the number of headache days, medication days and type of medication overuse at baseline. Daily use of headache medication and a higher ager were associated with lower odds for successful withdrawal (OR 0.50; 95% CI 0.30 – 0.83; p=0.008 resp. OR 0.98; 95% CI 0.96 – 0.99; p=0.017).