SM5002 Chap.9 Critically Appraising a Published LCA
Critically Appraising a Published LCA
What the group appraisal is for
The second assessed piece of work in the module is a group talk rather than a model. Six students share one published life cycle assessment from the healthcare literature and spend twelve minutes telling the class how sound it is.
The brief lists the elements a strong talk covers: an account of the methods the authors used, a critical judgement of those methods, a view on which other methodological routes were open to them, an interpretation and synthesis of the findings, the consequences for clinical practice and for policy, and a sense of how the paper sits beside the wider literature. A Vancouver reference page closes the deck.
The talks run on 4 or 11 November 2026, the slides go through Turnitin by 2 November 2026, and each talk is followed by questions from the floor, so the whole group needs to understand the paper well enough to defend a judgement it did not personally write.
The fourteen assigned papers span devices and whole services.
Several weigh reusable against disposable equipment, including laryngoscopes, central venous catheter insertion kits, flexible cystoscopes, trocar systems for laparoscopic gallbladder removal, blood pressure cuffs and duodenoscopes.
Others are wider in scope: cataract surgery, hysterectomy, coronary artery bypass grafting, a Swedish intensive care unit, diagnostic imaging across Australia, fluoride varnish in community dentistry, reprocessed devices in a hospital supply chain, and suction systems for fluids collected during surgery.
The appraisal questions are the same for each, but which question matters most changes with the design.
How the marks are distributed
The oral rubric has seven criteria. Understanding and explanation of the LCA methodology and critical appraisal of that methodology are each worth one fifth. Appraisal of alternative methodological approaches is worth fifteen percent.
Structure, organisation and communication is another fifteen. Interpretation and synthesis of results, referencing and use of evidence, and participation in peer evaluation are worth ten percent each. Read together, the three method criteria account for fifty five percent, which tells you where the slides should spend their time.
A deck that summarises the paper faithfully but never takes a position is answering the smallest part of the rubric.
The peer evaluation is a separate form on which every member rates every other member, and themselves, for their contribution to preparing and delivering the talk.
Two versions of the scale exist in the course materials, a five point version in the assignment booklet and a seven point version on the stand-alone form, so use whichever the submission page provides and write a short comment for each rating.
Questions that open up any published LCA
The lecture on critical appraisal and greenwashing, together with a 2024 commentary on what carbon footprinting can and cannot do for healthcare, gives a practical sequence.
Start with setting and date. Energy mix differs sharply between countries and shifts over time as grids decarbonise, so a result computed for one hospital in one year may not transfer to another. Then look hard at the boundary.
Every study draws a line around what it counts, and when the line leaves out downstream consequences, such as follow-up visits that a virtual consultation fails to prevent, an apparent saving can shrink or reverse. Third, test fairness.
Two products compared must deliver the same function, and a comparison between a large reusable instrument tray and a small disposable kit is not a comparison of like with like.
Beyond those three, look at which impact categories were reported, because an option that wins on climate change can lose on other categories such as fossil resource use or photochemical ozone formation.
Be wary of setting absolute numbers from different studies side by side, since inclusion rules, data granularity and conversion factors all differ; the commentary shows the same product family scoring materially lower under one method than another. Check the funding statement and any industry involvement.
Finally, ask what options the authors did not model, such as redesigning a device for repeated use rather than reprocessing a disposable one.
Turning appraisal into slides
A useful pattern is claim, evidence, consequence. The claim names one methodological choice. The evidence shows, with the paper's own numbers, why it is questionable.
The consequence says what a different choice would probably do to the conclusion and whether the conclusion would still guide practice. Alternatives deserve their own section, because they carry their own fifteen percent, and what the result means for clinicians and policy should come last so the audience leaves with a view on what a procurement team or clinician ought to do with the findings.
Because every member presents a portion, divide the talk by question rather than by section of the paper, so each speaker carries a judgement rather than a summary.
The most persuasive appraisals show arithmetic.
Dividing a total mass by the number of sets, recomputing a percentage change between two emission factors, or checking that a claimed halving really is close to one half takes seconds and demonstrates that the group has read the paper closely rather than repeating its abstract.
Handling the questions after the talk
Each presentation ends with several questions from the class, and those questions tend to follow the same three lines the appraisal itself uses.
Someone will ask whether the result would hold in Singapore or another setting with a different electricity mix. Someone will ask what the authors left outside the boundary. Someone will ask whether the two options really did the same job. Prepare a one sentence answer to each before the day, backed by a number from the paper, and agree in advance which member fields which line so the group does not talk over itself.
When a question exposes a weakness the group had not noticed, acknowledge it and say how it would change the conclusion; a candid answer that shows method thinking is worth more than a defensive one.
Lecture 7 frames all of this alongside greenwashing for a reason.
The same habits that let you appraise a peer-reviewed study let you test a supplier's environmental claim, and procurement teams increasingly meet such claims without the expertise to question them.
What this chapter covers
- 01
The oral presentation brief and its deadlines
- 02
Seven rubric criteria and the weight on method
- 03
Setting, date and transferability of results
- 04
System boundaries and what a study leaves out
- 05
Functional equivalence in reusable versus single-use comparisons
- 06
Funding, omitted alternatives and greenwashing risk
Worked example · free
Checking whether an electricity assumption changes a ranking
- 2Compute the change: (0.35 minus 0.28) / 0.35 = 0.07 / 0.35 = 0.20, a 20% fall in emissions per kWh.
- 2Identify which option depends more on electricity: the reusable device, whose washing and sterilising draw power every cycle.
- 2Conclude on direction and robustness: a cleaner grid lowers the reusable footprint further, so the ranking holds and widens, while results from a fossil-heavy grid would need rechecking.
Key terms
- Critical Appraisal
- A structured judgement of how well a published study's methods support its conclusions.
- Functional Equivalence
- The requirement that compared options deliver the same function, so differences in impact are not differences in job done.
- Emission Factor
- The greenhouse gas released per unit of activity, such as kilograms of CO2 equivalent per kWh of electricity.
- Greenwashing
- Presenting a product or practice as more environmentally beneficial than the evidence supports.
- Peer Evaluation
- The form on which each group member rates every member's contribution to preparing and delivering the talk.
Critically Appraising a Published LCA FAQ
How much of the oral mark depends on methodology?
Three criteria concern method directly: explaining it, critically appraising it, and weighing alternative approaches. Together they carry fifty five percent, so judgement about methods outweighs presentation polish and referencing combined.
Can we compare our paper's headline number with another study's?
Only with caution. Inclusion rules, data granularity and conversion factors differ between studies, and the reading list commentary shows one product family scoring materially lower under carbon footprinting than under a full life cycle assessment.
What counts as an alternative methodological approach?
Any defensible choice the authors could have made instead: a different functional unit, a wider boundary, another electricity mix or year, additional impact categories, sensitivity analysis on uncertain inputs, or an option they never modelled such as redesign for reuse.
Does every member have to speak?
Yes. Attendance is compulsory and each student presents a portion of the talk, after which the class asks questions, so every member should be able to defend the group's judgements, not only their own slides.
Assessment move
Read your assigned paper once for its story and a second time with the three questions on setting, boundary and fairness in hand, noting every number you could check by arithmetic. Draft one slide per judgement rather than one per paper section, and rehearse answers to the questions a sceptical audience would ask.
