Table 1

Cost calculations for menstrual products, by brand: Prices gathered on September 18, 2009, from London Drugs in West Vancouver, BC.*

PRODUCTUNITS PER PACKAGE, NCOST PER PACKAGE, $AVERAGE UNIT COST,$AVERAGE UNIT COST OF PRODUCT, $DivaCup139.9939.9939.99 Tampons0.24 • Tampax204.690.23 408.290.21 • o.b.184.690.26 407.990.20 • Playtex184.990.28 368.990.25 Pantiliners0.10 • Always404.990.124 727.990.11 • Kotex454.290.10 967.990.08 • Carefree464.490.10 Pads0.23 • Always184.490.25 368.990.25 • Stayfree144.490.32 487.990.17 • Kotex Maxi244.990.21 447.990.18 • * Previous cost estimates done by FLOW investigators over the past 2 years were as follows:$0.24 per tampon and $0.09 per pantiliner in a Victoria survey;$0.37 per tampon and $0.24 per pad in a Vancouver survey; and$38.99 per DivaCup at well.ca, $37.67 per DivaCup at lunapad.com, and$39.99 per DivaCup at londondrugs.com in an online survey of DivaCup prices. Our current estimate is in the same range as previous estimates; given that our methodology is more clearly laid out, we use our current estimate in our official cost calculations.

• The prospectively gathered diary data from the run-in month, upon which the tampon and pad number estimates are based, do not differentiate between pads and pantiliners, yet there is a substantial difference in cost between them. We have therefore gone through the presurvey data regarding subjects’ retrospective estimates of the tampons, pads, or pantiliners used per day to get an estimate of the average proportion of pads to pantiliners used in this population. The results were as follows: ratio of pads to pantiliners of 77 to 90; cost per pad or pantiliner, in dollars: ([0.77][0.23] + [0.90] [0.10])/1.67 = (0.177 + 0.09) /1.67 = 0.16.