salutary vs what the doctor ordered

salutary

adj
  • Effecting or designed to effect an improvement; remedial: salutary advice. 

  • Promoting good health and physical well-being; wholesome; curative. 

what the doctor ordered

noun
  • Exactly what is necessary or useful in a given situation; something very beneficial or desirable. 

How often have the words salutary and what the doctor ordered occurred in a corpus of books? (source: Google Ngram Viewer )