Table 2

Factors associated with potentially inappropriate prescribing identified in the studies included in this review.

PaperComorbiditiesPolypharmacy
Kristensen et al 2018 37 Community: polypharmacy (≥5 prescriptions) OR 1.50 (1.45–1.55); excessive polypharmacy (≥10 prescriptions) OR 1.51 (95% CI 1.44 to 1.58)
Nursing home polypharmacy OR 0.88 (95% CI 0.84 to 0.92); excessive polypharmacy OR 0.68 (95% CI 0.65 to 0.71)
Renom-Guiteras et al 201835 Comorbidity Charlson (0–2 vs 3–34): OR 1.35 (95% CI 1.03 to 1.77, p-value 0.029).
Oesterhus et al 201734 Cumulative Illness Rating Scale (range 0–52): OR 1.51 (95% CI 1.30 to 1.75).Polypharmacy (≥5 prescriptions) 45% and psychotropic polypharmacy (≥3 prescriptions) 2.8%. Number of medications: OR 1.50 (95% CI 1.29 to 1.73, p<0.001).
Sönnerstam et al 201753
Barry et al 201654 Polypharmacy (≥4 prescriptions): OR 7.6 (95% CI 6.6 to 8.7).
Cross et al 201655 Polypharmacy (≥5 prescriptions) and hyperpolypharmacy (≥10 prescription) were associated with high PIM prevalence
Hanlon et al 201536 Charlson Comorbidity Index (excluding dementia: range 0–33): OR 1.39 (95% CI 0.97 to 2.00)
Skoldunger et al 201533 PIM prevalence by Charlson Comorbidity Index level (0=9.5%, 1=15.9%, 2=16.6%, 3–34=26.4%).PIM prevalence by number of prescriptions (0–1=0.8%, 2–4=8.6%, ≥5=29.6%).
Tjia et al 201456 Difference in PIP prevalence by diagnosis: diabetes+7.6%, hypertension+8.7%, depression+8.3%, stroke+0.8%, heart failure −0.7% and osteoporosis: −4.6%.
Bosboom et al 201257
Montrastruc et al 201226 Association PIP with polypharmacy: OR 3.6 (95% CI 2.6 to 4.5).
Parsons et al 201258 Correlation between number of medicines prescribed and PIP=0.335 (p<0.01)
  • p values included when available in the original publication.

  • PIP, potentially inappropriate prescribing.