Association between drug shortage and factors at the DIN level
| Parameter or level | Branded DINs OR (95% CI) | Generic DINs OR (95% CI) |
|---|---|---|
| Market structure (Ref.: B and G single) | ||
| B and G multiple | 0.65 (0.45 to 0.94) | 0.68 (0.49 to 0.93) |
| B only | 0.68 (0.48 to 0.95) | |
| G single | 0.65 (0.45 to 0.93) | |
| G multiple | 0.62 (0.45 to 0.86) | |
| Overall p value* | 0.048 | 0.036 |
| DIN age (every year increase) | 1.02 (1.02 to 1.03) | |
| DIN age, yr (Ref.: < 3) | ||
| ≥ 3 | 1.85 (1.55 to 2.21) | |
| Route of administration or form (Ref.: oral solid regular release) | ||
| Injection | 1.16 (0.80 to 1.70) | 1.29 (1.00 to 1.66) |
| Oral nonsolid | 1.12 (0.67 to 1.89) | 1.09 (0.73 to 1.65) |
| Oral solid special release | 0.87 (0.59 to 1.28) | 1.17 (0.94 to 1.45) |
| Other | 1.28 (0.84 to 1.94) | 1.23 (0.87 to 1.72) |
| Overall p value* | 0.603 | 0.165 |
| Interaction of manufacturer type and top 50 manufacturer (Ref.: branded = yes, top 50 = yes) | ||
| Branded = no, top 50 = no | 3.22 (1.91 to 5.44) | |
| Branded = no, top 50 = yes | 2.23 (1.50 to 3.31) | |
| Branded = yes, top 50 = no | 1.59 (1.13 to 2.25) | |
| Overall p value* | < 0.001 | |
| Interaction of manufacturer size and top 50 manufacturer (Ref.: small) | ||
| Large, top 50 = no | 1.82 (1.25 to 2.64) | |
| Large, top 50 = yes | 2.40 (1.71 to 3.38) | |
| Medium, top 50 = no | 2.16 (1.45 to 3.23) | |
| Medium, top 50 = yes | 2.41 (1.39 to 4.17) | |
| Overall p value* | < 0.001 | |
| Essential medicine (Ref.: no) | ||
| Yes | 1.13 (0.99 to 1.30) | |
| Number of provinces on formulary (weighted) | 1.09 (1.07 to 1.11) | |
| Anatomic Therapeutic Chemical Classification (Ref.: sensory organs) | ||
| Alimentary tract and metabolism | 0.40 (0.20 to 0.81) | 0.30 (0.18 to 0.50) |
| Blood and blood-forming organs | 0.35 (0.14 to 0.86) | 0.12 (0.05 to 0.30) |
| Cardiovascular system | 0.57 (0.30 to 1.10) | 0.35 (0.22 to 0.56) |
| Dermatologicals | 0.51 (0.28 to 0.94) | 0.37 (0.22 to 0.64) |
| Genitourinary system and sex hormones | 0.45 (0.23 to 0.85) | 0.42 (0.25 to 0.71) |
| Systemic hormonal preparations, excluding sex hormones and insulins | 0.22 (0.10 to 0.51) | 0.35 (0.18 to 0.70) |
| Anti-infectives for systemic use | 0.31 (0.15 to 0.62) | 0.41 (0.25 to 0.67) |
| Antineoplastic and immunomodulating agents | 0.22 (0.11 to 0.45) | 0.36 (0.21 to 0.63) |
| Musculoskeletal system | 0.63 (0.27 to 1.43) | 0.27 (0.16 to 0.45) |
| Nervous system | 0.43 (0.23 to 0.79) | 0.40 (0.25 to 0.64) |
| Antiparasitic products, insecticides and repellents | 0.60 (0.10 to 3.60) | 0.28 (0.08 to 0.92) |
| Respiratory system | 0.64 (0.34 to 1.21) | 0.48 (0.29 to 0.81) |
| Various | 0.30 (0.09 to 0.97) | 0.46 (0.17 to 1.23) |
| Overall p value* | 0.004 | < 0.001 |
| Model fit statistics | ||
| C-statistic | 0.68 | 0.64 |
| AIC | 2126.38 | 7278.45 |
| Log-likelihood | −1038.19 | −3611.23 |
Note: AIC = Akaike information criteria, B = branded manufacturer, CI = confidence interval, DIN = Drug Identification Number, G = generic manufacturer, OR = odds ratio, Ref.= reference category.
↵* Based on type III Wald Test.