Table 2 Rate ratio for Parkinson’s disease during 2008 to 2014 for salbutamol prescribed during 2004 to 2007 among the entire population of Norway.

DDDs, defined daily doses.

Rate ratio (95% CI)
Users 2004–2007Cases 2008–2014Multivariate-adjusted*
Salbutamol
Never user4,201,01123381 (ref)
Low (<60 DDDs)152,965680.96 (0.76 to 1.23)
Medium (60 to 180 DDDs)72,911230.60 (0.40 to 0.91)
High (≥180 DDDs)69,511250.45 (0.31 to 0.67)

*Adjusted for age (in 5-year periods), sex, and level of education.