Table 2.

Examples from the literature of different definitions of (in)appropriate antimicrobial use for LRTIs in the elderly

Setting	Definition of inappropriate antimicrobial use	Appropriateness of RTI treatment	References
Tobia et al., 2008 Outpatients at emergency department [N = 153]	Medication Appropriateness Index (MAI)  1. Indication (e.g. presence of symptoms)  2. Effectiveness  3. Dosage  4. Directions (e.g. route)  5. Practicality (e.g. adherence)  6. Drug–drug interactions  7. Drug–disease interactions  8. Unnecessary duplication  9. Duration  10. Expensiveness (least expensive alternative) Rating  A, appropriate; B, marginal; C, inappropriate	n = 99 (65%)	[93]
Van Buul et al., 2015 Long-term care facility [N = 208]	Algorithm for RTI based on guidelines and national expert panel  Distinction between: (1) acute cough; or (2) no acute cough but fever; or (3) no cough and fever  Then presence/absence of abnormalities on lung auscultation, COPD, CRP results, other airway and non-airway symptoms, and certain risk factors Rating  A, appropriate; B, probably appropriate; C, probably inappropriate; D, inappropriate; E, insufficient information	n = 180 (86.5%; range 60.0–96.2)	[41]
Vergidis et al., 2011 Long-term care facility [N = 752]	Appropriate (with/without antimicrobial prescription)  With: when effective drug was used  Without: when use of an antimicrobial was not indicated Inappropriate  With: when a more-effective drug was indicated  Without: undefined Unjustified  With: use of any antimicrobial was not indicated  Without: when use of an antimicrobial was indicated Insufficient information for categorization	n = 592 (79%)	[50]
Loeb et al., 2001 Long-term care facility [N = 646]	Assessment of prescriptions to see if they fulfilled the diagnostic criteria  At least three of the following: (1) new/increased cough; (2) new/increased sputum production; (3) fever; (4) pleuritic chest pain; (5) new or increased physical findings on chest examination; (6) new/increased shortness of breath or respiratory rate more than 25/min, or worsening mental or functional status	n = 375 (58%)	[49]

LRTIs lower respiratory tract infections, RTI respiratory tract infection, COPD chronic obstructive pulmonary disease, CRP C-reactive protein