Secondary outcome measures
dizziness, Specific pain, headache, Dizziness
Secondary outcomes were collected at the 20-year follow-up. Frequency of neck/arm pain and headache, dizziness and other neck-related problems were rated on a 5-point scale rating scale (0 = never, 4 = constant). For statistical reasons, ratings were categorized as never (0), occasionally [Specific pain ratings of neck, arm, and headache were collected using the 100 mm VAS. Individuals with headache related to their neck completed the Swedish version of the HIT-6 questionnaire [Dizziness at rest and during movement, and self-rated balance problems were assessed by a 100 mm VAS [A 6-point rating scale ranging from completely recovered to much worse [