Quantifying the cost of single-use minims and multidose bottles for eye drops in routine ophthalmic practice: a multicentre study



      To compare costs between two different eye drop delivery modalities: multidose bottles and single-use minims.


      Retrospective cohort study.


      Monthly dilating eye drop costs and quantities (tropicamide 1%, phenylephrine 2.5%, cyclopentolate 1%) were studied over a 2-year period between April 2013 and March 2015 at 2 tertiary ophthalmic centres (Royal Alexandra Hospital [RAH, Edmonton] and Rockyview General Hospital [RGH, Calgary]). In April 2014, RAH switched its dilating eye drop practice from predominantly multidose bottles to single-use minims, whereas RGH continued using predominantly multidose bottles. Eye drop volume and total and per-patient eye drop costs were quantified at RAH before switching (pre-intervention) and after (post-intervention) using an interrupted time-series analysis with RGH as a control. A counterfactual analysis was also performed. Significance was obtained using independent t-testing.


      After switching to single-use minims, RAH experienced changes in the following: an increase in single-use minims as a proportion of total eye drop utilization (from 5.6% to 89.1%; p = 0.001), an increase in total eye drop cost by $2117 per month (95% confidence interval [CI], $1354–$2880; p < 0.001), an increase in per-patient costs by $984 per 1000 patients per month (95% CI, $674–$1293). Contrastingly, RGH did not experience similar changes. Ultimately, the cost of switching to single-use minims was $22 481 (95% CI, $7830–$31 336) over a 12-month period.


      If safe eye drop practices are enforced via proper protocols, the use of multidose bottles may be a more cost-effective option than single-use minims for routine clinical practice.


      Comparer le coût de deux modes d'administration de collyres: flacons multidoses et flacons unidoses.


      Étude de cohortes rétrospective.


      On a comparé, sur une base mensuelle, le coût et les quantités des collyres mydriatiques (tropicamide à 1 %, phényléphrine à 2,5 % et cyclopentolate à 1 %) utilisés pendant 2 ans entre avril 2013 et mars 2015 dans 2 centres de soins tertiaires en ophtalmologie (Hôpital Royal Alexandra [RAH, Edmonton] et Hôpital général Rockyview [RGH, Calgary]). En avril 2014, le RAH a remplacé les flacons de collyres mydriatiques surtout multidoses par des flacons unidoses, tandis que le RGH a continué d'utiliser surtout des flacons multidoses. Le volume de collyres de même que le coût total et par patient ont été calculés au RAH avant et après le changement de conditionnement en recourant à une analyse des séries chronologiques interrompues, le RGH ayant servi de témoin. Une analyse hypothétique a également été réalisée. Le seuil de signification a été obtenu grâce au test t pour échantillons indépendants.


      Après avoir opté pour les flacons unidoses, le RAH a observé les phénomènes suivants: hausse du nombre de flacons unidoses en proportion de l'ensemble des collyres utilisés (de 5,6 % à 89,1 %; p = 0,001), augmentation de 2117 $/mois du coût total des collyres (intervalle de confiance [IC] à 95 % : 1354 $–2880 $; p < 0,001), hausse de 984 $ des coûts/patient par tranche de 1000 patients par mois (IC à 95 % : 674 $–1293 $). À l'opposé, le RGH n'a pas subi pareils changements. En fin de compte, le coût du remplacement des flacons multidoses par des flacons unidoses s'est élevé à 22 481 $ (IC à 95 % : 7830 $–31 336 $) sur une période de 12 mois.


      Dans la mesure où les protocoles d'administration de collyres à partir de flacons multidoses sont soigneusement respectés, ces derniers représentent peut-être une option plus avantageuse sur le plan économique que les flacons unidoses dans la pratique clinique habituelle.
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