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Published on: February 15, 2019
Measuring injection-site pain associated with vaccine administration in adults: a randomised, double-blind,
1Department of Epidemiology, Merck Research Laboratories, West Point, PA 19486-0004, USA.
Background:
Pain at the injection site is one of the most commonly-reported local reactions associated with administration of a vaccine, but it has not been quantified by a validated instrument for pain measurement. We conducted a randomised, double-blind clinical trial to evaluate the measurement characteristics of two commonly-used pain questionnaires, the McGill Present Pain Intensity (PPI) and the Brief Pain Inventory (BPI) Current Pain Question, in the assessment of intramuscular injection-site pain associated with vaccine administration. The PPI measures pain on a scale of 0 (no pain) to 5 (excruciating pain) and the BPI measures pain on a scale of 0 (no pain) to 10 (pain as bad as you can imagine).
Methods:
Two hundred healthy adults were randomised to one of the five regimens: tetanus and diphtheria toxoids adsorbed (Td), aluminum hydroxide adjuvant (alum), physiological saline, or one of the two licensed hepatitis A vaccines, VAQTA, or HAVRIX. Pain assessment was made at eight time-points over a 2-day period after injection.
Results:
The differences in the time-averaged pain (+/- standard deviation) on the PPI were statistically significant between Td (0.58+/-0.59) and either saline (0.14+/-0.23) (p < 0.005) or alum (0.22+/-0.35) (p < 0.01). Reported time-averaged pain were significantly lower for VAQTA than HAVRIX (p = 0.028). Similar differences were observed for the BPI.
Conclusions:
Both instruments have sufficient discriminative validity to distinguish between different levels of injection-site pain in adults.
