One diclofenac gel needed 1.8 people treated; other gels needed over 4
Against a dummy gel, diclofenac in one emulsion needed 1.8 people treated for one more to halve their sprain pain, and ketoprofen gel 2.5. The same actives elsewhere needed over 4.
What the study found
For a sprain, the gel it comes in matters as much as the drug
Against a matching dummy gel, diclofenac in one particular emulsion formulation needed 1.8 people treated for one more to get at least half their pain gone after a sprain or strain, and ketoprofen gel 2.5. The same actives in other gels, creams and plasters needed more than 4.
The caveat · Best figure rests on two studies
The best diclofenac figure rests on two studies, and some of the ketoprofen data come from 1980s trials with loosely defined outcomes. Around 5,900 participants' worth of registered but never fully reported efficacy data was identified and could not be obtained, which is the direction publication bias usually runs. Only 220 people across all 61 trials were given a tablet for comparison, so the comparison with swallowing one is thin.