Metrics that Matter: the Basics
Evidence-based medicine is the foundation of effective health care. Likewise, hospital waste reduction strategy should be data-driven, via monthly metrics. At baseline, you want to know how much waste is generated, at what cost, and at what rate of generation. There are many healthcare waste streams. For simplicity, we reference municipal waste in this post, and track four waste streams: landfill, compost, recycled construction debris (C&D), and recycling.
Input metrics: Weight and cost, by waste stream
Track these numbers monthly, available via sustainability data management software or directly from waste vendors.
After several months, one can start seeing a trend of the weights trending upwards, stabilizing or decreasing. In such instances, the hospital waste team can evaluate efficiency measures to optimize service levels.
Input metric: Adjusted patient days
Adjusted patient days (APD) is one of many hospital productivity measures that may be used as a normalizing factor to calculate waste generation rate. APD is a good normalizing factor as it provides a comprehensive measure of total hospital business, adjusting for all services provided beyond acute care.
Calculated metrics:
Use input metrics to calculate the following monthly figures:
Total waste by weight and cost
The primary goal of any waste reduction strategy is less total waste. Make this data point the first metric, following the waste reduction hierarchy of reduce, reuse, and recycle.
In the waste chart below, we can track monthly total waste; comprised of all four waste streams.
Diversion rate
Track recycling and compost as percent diverted from landfill. Don’t forget to include shredded paper as a recycling stream.
Below the sample pie chart shows hospital waste generation by waste stream. The solid waste generation rate is 65%. The total diversion rate is 35% (total percentage of compost, C&D and recycling). Month to month, one can observe if the diversion rate goes up or down to measure the success of waste reduction initiatives.
Total waste per APD (lbs.)
This metrics tracks the rate of waste generation, or how much waste is generated for each unit of patient volume.
The sample graph below shows the waste generation rate for each of the four waste streams. The total waste per APD (in pounds) is tracked over a three month period.
Waste per APD (lbs.) by waste stream
As shown in the graph above, track each waste stream by APD, and set diversion targets using this methodology.
A few recommendations:
Healthcare waste is complicated. The task at hand is understanding and presenting metrics it in a way that is clear, accessible, and compelling. To achieve that end,
Get to know the numbers, including source data, trends and variations
Make it visual - chart the metrics and create a monthly dashboard
Make it visible - share this data internally, and reference the numbers when planning, prioritizing, and evaluating waste reduction initiatives.
There are additional metrics to consider when evaluating the value and performance of a waste management program. More to come on the topic.
