Median consumer prices (US dollars) of insulin, by place of manufacture and combined
| Combined (domestically manufactured plus imported) (1) | Domestically manufactured insulin (2) | Imported insulin products (3) | p Value | |
|---|---|---|---|---|
| Human insulin | ||||
| Phial | US$5.6 (n=106) | US$5.6 (n=98) | US$5.6 (n=8) | 0.0011*† |
| Cartridge | US$11.2 (n=24) | US$8.5 (n=5) | US$11.4 (n=19) | 0.0105* |
| Pen | US$18.5 (n=4) | ‡ | US$18.5 (n=4) | – |
| Analogue insulin | ||||
| Phial | ‡ | ‡ | ‡ | – |
| Cartridge | US$25.0 (n=19) | ‡ | US$25.0 (n=19) | – |
| Pen | US$32.8 (n=21) | ‡ | US$32.8 (n=21) | – |
The prices of all survey insulin products with variable pack sizes (millilitres) and strength were adjusted to 10 mL 100 IU/mL pack for purpose of comparisons.
n refers to the number of insulin prices available to calculate median insulin consumer price.
*Statistically significant at α significance level of 0.05.
†While the medians in comparison are same, the distribution is different with lower prices in domestically manufactured insulin group. This is because the Wilcoxon rank-sum test ranks all of the observations from both groups and then sums the ranks from one of the groups which is compared with the expected rank sum. Although uncommon, it is possible for groups to have different rank sums and yet have equal or nearly equal medians.
‡No insulin product in the respective delivery option was found in the facility survey, and therefore p value was not calculated.