Medical Waste Due to Intravitreal Injection Procedures in a Retina Clinic

Abstract

Purpose:

Medical waste contributes to health care costs and has a direct negative impact on the environment. The goals of this study are to quantify and categorize the medical waste generated by intravitreal injection procedures and identify opportunities to reduce waste.

Methods:

This is a prospective observational series. Medical waste from intravitreal injections was collected from 337 consecutive intravitreal injections by a retina specialist over 2 weeks. The waste was sorted, photographed, weighed, and recorded.

Results:

A total of 65.6 kg of waste was collected across 3 broad categories: (1) shipping waste (cardboard boxes, foam coolers, cold packs, and bubble wrap); (2) waste from administering the intravitreal injection (nitrile gloves, tissues, wipes, and plastic or paper packaging); and (3) biohazard waste (used syringes and needles). Shipping waste contributed 83% of the overall waste, by mass, and varied greatly based on the size of the order and how efficiently shipments were packed. Cold packs, foam coolers, cardboard/paper, and nitrile gloves were the greatest contributors to carbon emissions and landfill.

Conclusions:

Waste due to shipping of medication is a major opportunity for reducing the environmental impact of intravitreal injections. Buying in bulk is a simple way for retina practices to reduce waste. Manufacturers should consider less bulky packaging for branded intravitreal injections; distributors and outsourcing facilities should consider take-back programs to reuse coolers and cold packs. Improved sustainability in the treatment of retinal disease is achievable but requires awareness and optimization of a clinic’s routine.

Introduction

Medical waste in developed countries represents a significant component of landfill volume and emissions, ¹ causing an unsustainable impact on our environment. ^2,3 Whereas residential recycling is increasingly common and socially expected, health care facilities lag in efforts to reduce, reuse, and recycle. This is partly owing to infection prevention and quality control, ⁴ yet hospitals and clinics still have the capacity to safely reduce physical waste and wasteful practices. ^{5 -8} Furthermore, it is important for health care to improve sustainability, as waste increases health care costs ⁹ and directly affects the environment. ²

Intravitreal injection is the most common ophthalmic procedure worldwide. ¹⁰ As such, intravitreal injection is a major contributor to medical waste generated in a retina clinic. The purpose of this study is to bring awareness to the medical waste we produce and to identify opportunities for reducing the negative impact to the environment.

Methods

Medical waste related to intravitreal injection was collected by a single retina specialist over a 2-week period, August 24 to September 4, 2020. Waste was collected from the 3 areas of the clinic most directly associated with intravitreal injection: (1) “receiving,” where shipments of intravitreal drugs are unpacked; (2) technician stations, where injections are prepared for administration; and (3) examination rooms, where injections are administered to patients. Shipping packaging was collected from shipments of bevacizumab, ranibizumab, aflibercept, and brolucizumab but not from ancillary supplies (eg, facial tissue, cleaning supplies, Tono-Pen covers, or dilation drops). Waste was not collected from the front desk, billing office, screening rooms, or testing rooms. Waste was normalized per injection for purposes of analysis and reporting.

Collected waste was sorted into categories, weighed using a multifunction scale (Greater Goods, B01JTDG084), photographed (iPhone X), and recorded in a spreadsheet (Microsoft Excel, version 16.40).

Environmental impact was estimated for the major material components of intravitreal injection. Usage was scaled to 52 weeks for 1 retina specialist. Carbon dioxide (CO₂) emissions were calculated using published emissions factors ^{11 -13} that reflect a life cycle analysis (including harvesting raw materials, manufacturing, transportation, and disposal) of the components. Disposal was assumed to be incineration for sharps/biohazard and landfill for other components.

Results

During the 2-week study period, 337 injections were administered (Figure 1A) and 9.1 kg of waste from administering the injections was collected from examination rooms and technician stations (Figure 1B). An additional 56.7 kg of shipping waste was collected from 1194 doses of medication received (Figure 1B). Shipping packaging from 4 shipments of aflibercept and ranibizumab from the distributor (Besse Medical) and 6 shipments of bevacizumab from the outsourcing facility (Pine Pharmaceuticals) were collected. An outlier shipment of 15 sample aflibercept in a particularly heavy (21.3 kg) shipping cooler (E280C Sonoco ThermoSafe, Nomadic) from the manufacturer was excluded because the shipping container was significantly heavier compared with other containers, and because no samples were administered during the study period.

Figure 1.

Medical waste due to intravitreal injection collected from a retina clinic over a 2-week period. (A) Sharps and syringes. (B) Waste associated with administration of the injections and shipping.

Shipping waste consisted of cardboard boxes, disposable foam coolers, cold packs, and bubble wrap/air pillows (Figure 2). Waste from administration of the injections included nitrile gloves, facial tissues, paper towels, wipes, plastic or paper packaging, sharps, and syringes (Figure 3).

Figure 2.

Waste associated with shipping of medication. (A) Cardboard box. (B) Disposable foam cooler. (C) Cold packs. (D) Bubble wrap and air pillow.

Figure 3.

Waste associated with administration of the injection. (A) Autoclave packaging. (B) Nitrile gloves. (C) Tissues and paper towels. (D) Cardboard package and package insert. (E) Plastic tray and Tyvek (DuPont) lid. (F) Prefilled syringe, needle, cap, and rubber stopper.

Per-injection waste is shown in Table 1. Although biohazard waste including syringes and needles requires special disposal, it represented only 1.5% of the medical waste associated with these procedures. The categories contributing most to overall waste included cold packs (62.5%), cardboard boxes (10.4%), foam coolers (8.4%), and nitrile gloves (6.0%). Shipping waste (cardboard box, foam cooler, cold packs, and air pillows) contributed 83% of the overall waste, by mass (Figure 4).

Table 1.

Medical Waste Associated With an Intravitreal Injection in a Retina Clinic.

Waste	Mass per injection, g	Percentage of total
Sharps and biohazard for incineration
Mixed syringes, needles, and vials	2.0 ± 0.2	1.5
Waste due to administering procedure
Nitrile examination gloves	11.4 ± 1.4	6.0
Tissue, paper towels, and wipes	6.6 ± 0.6	3.5
Cardboard box and package insert	6.2 ± 1.3	3.3
Plastic and mixed plastic/papera wrappers	6.2 ± 1.3	3.3
Miscellaneousb	1.5 ± 0.3	0.8
Waste due to shippingc
Cardboard box	19.7	10.4
Foam cooler	16.0	8.4
Cold packs	118.5	62.5
Bubble wrap	1.4	0.7

^a Autoclave packaging and wrappers for syringes and needles.

^b Plastic caps, rubber stoppers, and cotton-tip applicators.

^c Calculated by averaging the 5 shipping scenarios shown in Figure 5.

Figure 4.

Proportion of total waste (by mass) due to shipping, administration of the injection, and biohazard.

Shipping waste per dose varied widely depending on the type of medication and the number of doses in the shipment (Figure 5). Repackaged bevacizumab was packaged relatively compactly (in plastic envelopes) compared with ranibizumab or aflibercept, which were packaged in bulkier individual containers; therefore, far fewer of the latter fit into a shipping cooler. Also, bigger orders allowed for more efficient delivery of medications with less waste per dose both for branded drug (Figure 5A) and repackaged bevacizumab (Figure 5B).

Figure 5.

Shipping weight per dose, depending on the size of the shipment. The per-dose shipping weight decreased for larger shipments with more items, for the (A) branded drugs and for (B) bevacizumab.

The estimated cost of disposal of components, along with CO₂ emissions and landfill volume, for a theoretical retina specialist is shown in Table 2. Substantial CO₂ is emitted, and a significant volume of foam coolers, cold packs, cardboard, and nitrile gloves are deposited, into landfill annually because of intravitreal injections.

Table 2.

Waste Management Cost and Environmental Impact of Intravitreal Injections (Annual, per Retina Specialist).

Component	Quantity,a kg	Clinic waste removal cost,b $	Literature-derived emissions factor, kg CO2/kgc	Estimated CO2 emissions, kg CO2	Estimated landfill,d m3
Cardboard/paper	40	500	1.4 11,12	56	0.1
Cold packs, LDPE	250	3100	0.5 11,12	130	0.25
Foam coolers	35	400	2.7 11,12	94	40
Nitrile gloves	25	300	3.3 13	83	0.025
Sharps/biohazard	6	4500	6.0 11,12	36	NA

Abbreviations: LDPE, low-density polyethylene; NA, not available.

^a Calculated from the present study, scaled to 52 weeks.

^b Derived from incineration costs and waste management costs at Retina Center of Minnesota.

^c Emissions factor reflects the carbon emissions associated with the materials, manufacturing, transportation, and disposal of components listed; disposal is assumed to be incineration for sharps/biohazard and landfill for other components. The emissions factor for cold packs is calculated using a literature-derived emissions factor for LDPE, reduced by a factor of 4 for aqueous gel.

^d Assumed density of 700 kg/m³ cardboard and paper, 1000 kg/m³ cold packs, 1 kg/m³ foam cooler, and 1000 kg/m³ nitrile gloves.

Conclusions

In this study we measured on average 190 g of medical waste produced with each intravitreal injection, including sharps and biohazard waste (1.5%), waste from administering the procedure (16%), and waste from temperature-controlled shipping on orders of medication (83%). Because we did not consider waste related to the front desk, screening, testing, billing, or shipping of ancillary supplies, our measurement may be underestimated by up to 25%. Even so, this study brings awareness to the magnitude of medical waste produced in retina clinics. The results highlight shipping waste as a point of focus, as well as other opportunities for reduction and recycling.

Buying in bulk is a simple and cost-effective way to reduce shipping waste. For example, shipping waste was 30% less for a shipment of 200 bevacizumab doses compared with 100 bevacizumab doses, thanks to fewer foam coolers and cold packs per dose. Also, the individual box packaging for branded drugs is significantly larger than might be required; thus, manufacturers could help make shipping more efficient by reducing the sizes of their boxes so that more items can fit within a cooler.

Paper and cardboard recycling is well known to many of us at home and available in most municipalities. It follows that positioning recycling stations where shipments are unpacked (to collect boxes) and technician stations where injections are prepared (to collect package inserts and individual box/paper packaging) may encourage recycling of paper and cardboard. It is worth noting that used tissues and paper towels are generally not recyclable because they are of too low quality and should not go into organics recycling if they are soiled with cleaning products, betadine, or other antibacterial chemicals that could negatively affect organic composting. Although paper and cardboard are recyclable, the recycled products are still processed, with associated cost, CO₂, and environmental impact.

Some manufacturers and/or distributors of nitrile gloves have a take-back program whereby gloves can be collected and returned in bulk to be processed into plastic pellets for reuse. These programs are feasible but require dedicated sorting and/or collection of the gloves. Biodegradable nitrile gloves are commercially available, but the environmental impact of their breakdown is concerning because of the possibility that microplastics are released in the process.

Foam coolers present a unique problem for retina clinics because of the high magnitude of temperature-sensitive drugs that are administered in-clinic, requiring (cold) temperature-controlled shipping from the distributor or outsourcing facility, and from clinic to clinic within retina practices. Foam is inexpensive to manufacture but bulky and nonbiodegradable, which economically promotes single use despite negative environmental impact. Foam coolers can persist in landfills for hundreds of years. ¹⁴ In our opinion, foam coolers are the component of intravitreal injection with the greatest environmental impact when considering CO₂ emissions, landfill volume, and longevity of the waste product.

A theoretical solution would be circular return shipping of the cooler and cold packs to the outsourcing facility, manufacturer, or distributor to reuse with the next shipment, although such programs do not exist to our knowledge. Further studies are needed to determine whether circular shipping is financially feasible and environmentally beneficial.

Limitations of our study include that this study was based on waste collected from a single retina specialist (G.G.E.) and therefore depends on the specialist’s individual routine, including preference for topical anesthesia and preference for wearing new nitrile gloves for each patient. A survey by Lau et al of intravitreal injections by US-based retina specialists found 51% of retina specialists report glove use, whereas others do not. ¹⁵ Our study also points to large variation in waste depending on large vs small orders of medication (small orders are more wasteful in terms of shipping components). Similarly, the usage of prefilled syringes as opposed to vials is beneficial because less overfill and fewer syringe components are required. Also, branded drug vs bevacizumab varies. Because the shipping weight per dose was approximately 7 times greater for ranibizumab and aflibercept compared with bevacizumab, there was considerably more shipping waste (and CO₂ emissions and landfill) for the branded drugs, highlighting an opportunity for improvement. Despite these variations amongst retina specialists, the opportunity to conserve resources and minimize environmental impact is universal.

Further limitations include that we did not consider waste upstream of our clinic, such as medical waste that occurs at the outsourcing facility or in transport from the manufacturer to the distributor. Also, this study was not designed to test ways to reduce waste or estimate the cost/benefit of switching to a less wasteful process.

In summary, in this study we measured the medical waste associated with intravitreal injection in a retina clinic, which amounted to 190 g of waste per injection. Most notably, 83% of the waste was a byproduct of procuring medication, highlighting an important target for waste reduction. Our study indicates that fewer large shipments of medication are less wasteful compared with multiple small shipments. Furthermore, we see opportunity for manufacturers to produce less-bulky packaging for branded drugs and supply chain entities to explore return shipping of coolers and cold packs for reuse.