Studying a Cause You Cannot Assign
Take the reading one piece at a time. For each piece: read it once, underline the sentence that says what happens, then look up any word in the list. Tap a word to see its definition.
Piece 1 of 2
A five-country case-control study collected mothers of babies born with a non-syndromic cleft (cases) and mothers of babies born without a cleft (controls), matched by hospital and month of birth, and asked both groups about pregnancy exposures [PMID:37118740]. Notice the direction of the arrow: the researchers started with the outcome (cleft or no cleft) and looked backward at exposures. They did not assign anything.
Piece 2 of 2
To see how the math works, here is a small worked table in that same backward style. The specific cell counts are a constructed teaching dataset, not the paper's actual numbers; they are sized to give a clean odds ratio for students to compute. Among 100 mothers of babies WITH a cleft (cases): 40 reported the exposure, 60 did not. Among 100 mothers of babies WITHOUT a cleft (controls): 20 reported the exposure, 80 did not. In a 2-by-2 table, cases are 40 exposed and 60 not, controls are 20 exposed and 80 not.
Reading the Research
- Skim the title and abstract first to get the gist.
- Circle the one sentence that states the main claim.
- Box the evidence the authors give for that claim.
- Mark one sentence that confuses you, and move on.
Now put it together: In one or two sentences, say what this whole reading is telling you about Mateo. Then go back to the lesson and fill in the guided notes.