Table 3.
Measures of internal consistency reliability for the three-factor Migraine-Specific Questionnaire measurement model, by study (baseline data)
| Item-scale correlations corrected for overlap | Cronbach’s alpha/average inter-item correlation | Cronbach’s alpha—item deleted | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| RR | RP | EF | ||||||||
| Std 1 | Std 2 | Std 1 | Std 2 | Std 1 | Std 2 | Std 1 | Std 2 | Std 1 | Std 2 | |
| Role function-restrictive (RR) | 0.93/0.71 | 0.93/0.70 | ||||||||
| 1 […]interfered with how well you dealt with family, friends and others who are close to you? | 0.73 | 0.74 | 0.64 | 0.63 | 0.59 | 0.56 | 0.92 | 0.92 | ||
| 2 […]interfered with your leisure time activities, such as reading or exercising? | 0.78 | 0.75 | 0.70 | 0.65 | 0.54 | 0.48 | 0.91 | 0.92 | ||
| 3 […]difficulty in performing work or daily activities because of migraine symptoms? | 0.81 | 0.83 | 0.75 | 0.72 | 0.56 | 0.53 | 0.91 | 0.91 | ||
| 4 […]keep you from getting as much done at work or at home? | 0.78 | 0.79 | 0.69 | 0.71 | 0.58 | 0.54 | 0.91 | 0.91 | ||
| 5 […]limit your ability to concentrate on work or daily activities? | 0.82 | 0.82 | 0.73 | 0.67 | 0.59 | 0.51 | 0.91 | 0.91 | ||
| 6 […]left you too tired to do work or daily activities? | 0.76 | 0.75 | 0.71 | 0.70 | 0.53 | 0.56 | 0.92 | 0.92 | ||
| 7 […]limited the number of days you have felt energetic? | 0.69 | 0.69 | 0.61 | 0.55 | 0.53 | 0.49 | 0.92 | 0.92 | ||
| Role function-preventive (RP) | 0.88/0.70 | 0.98/0.71 | ||||||||
| 8 […]cancel work or daily activities because you had a migraine? | 0.72 | 0.72 | 0.79 | 0.80 | 0.50 | 0.54 | 0.84 | 0.85 | ||
| 9 […]need help in handling routine tasks such as every day household chores, (...) when you had a migraine? | 0.71 | 0.65 | 0.72 | 0.73 | 0.55 | 0.59 | 0.86 | 0.87 | ||
| 10 […]stop work or daily activities to deal with migraine symptoms? | 0.72 | 0.70 | 0.74 | 0.75 | 0.53 | 0.54 | 0.85 | 0.86 | ||
| 11 […]not able to go to social activities such as parties, (...) because you had a migraine? | 0.71 | 0.70 | 0.75 | 0.77 | 0.50 | 0.54 | 0.85 | 0.86 | ||
| Emotional function (EF) | 0.80/0.61 | 0.83/0.66 | ||||||||
| 12 […]felt fed up or frustrated because of your migraines? | 0.54 | 0.56 | 0.42 | 0.49 | 0.54 | 0.59 | 0.83 | 0.85 | ||
| 13 […]felt like you were a burden on others because of your migraines? | 0.61 | 0.53 | 0.59 | 0.59 | 0.73 | 0.73 | 0.63 | 0.71 | ||
| 14 […]afraid of letting others down because of your migraines? | 0.55 | 0.54 | 0.51 | 0.56 | 0.68 | 0.75 | 0.68 | 0.69 | ||
Bolded cells represent correlations between items and their corresponding scale total score (calculated after exclusion of the item) and are hypothesized to be highest within the corresponding row
Std study