Scheme: Construction of the indicator "Test_a".
| Item | Assigned value |
| dd1: "Do you have headaches for more than 3 times a month, every month?" | Yes = 2 No = 0 |
| dd2: "How many painkillers do you get every month for headaches?" | |
| dd2_1: "up to 3" | Yes = 0 No = 0 |
| dd2_2: "4 - 8" | Yes = 1 No = 0 |
| dd2_3: "8 or more" | Yes = 2 No = 0 |
| dd3: "Do you often think that headache does not respond to painkiller?" | Yes = 2 No = 0 |
| dd4: "During the headache have you ever had nausea or vomiting?" | Yes = 1 No = 0 |
| dd5: "Is pain pulsating or worsening with movement?" | Yes = 1 No = 0 |
| dd6: "When you have headaches, do you continue to carry out your normal activities" | Yes = 0 No = 2 |