The Medical Manuscript | Understanding Medical Research

[Music] all right now that you know what goes into getting a manuscript published it's time we look at the manuscript itself the medical manuscript the central point of this entire course our goals here to understand that a medical manuscript is a highly structured document there are rules to writing them which give rise to rules for reading them and it's really not as hard as you think and so to sort of figure out how we would do a medical manuscript we're going to conduct an imaginary little study here and wend our way through writing the manuscript a young researcher has decided to test an important hypothesis that providing water to thirsty graduate students will decrease their thirst after securing funding and approval from his institutional ethics committee he enrolls 100 thirsty subjects 50 of them are randomized to water drinking while the remaining 50 are given an empty glass to stare at for a while after 10 minutes the participants are asked to rate their thirst level after careful data analysis the intrepid young researcher discovers that the group who drank water had significantly lower thirst scores than those who did not he quickly writes up his findings as a research paper and submits it to the most prestigious journal in the water drinking field the journal of the american moisture association or jama this publication helps him to attain that promotion he was gunning for a grant to study water drinking in an even larger population and a prestigious award the h2o bell prize let's talk about how to read that earth-shattering research paper so what that study showed us is that drinking water reduces thirst this is not an earth-shattering result but it is something that we can put into a medical manuscript and disseminate to the wider world so let's talk about the components of the medical manuscript starting with the simplest part the title titles have exactly one job to tell you what the exposure is and what the outcome is in that study so here are four different titles of recent medical studies and we'll give you links to all of these studies but just to give you a sense of how we go through this number one the diagnostic assessment of deep learning algorithms for detection of lymph node metastases in women with breast cancer so you need to ask yourself is there an exposure and is there an outcome in that title well the exposure here is this deep learning algorithm you don't need to know what that is you just need to know that it is an exposure to something they are doing to someone or using on someone and the outcome is the detection of lymph node metastases let's do one more and you can look at the rest on your own ginkgo biloba extract improved cognitive and neurological functions of acute ischemic stroke a randomized controlled trial the exposure here is ginkgo biloba extract people were exposed to that deliberately in this case and the outcome is cognitive and neurologic function again how they measure that outcome and what the assessment is is immaterial when you're looking at the title but you should be able to figure out is there an exposure and outcome in the study and what are they in the case of our water drinking study the exposure and outcome is pretty simple the exposure was drinking water and the outcome was a reduction in thirst and so we might title this study something like the effects of drinking water on thirst in postgraduate students a randomized open label trial our title has done its job after the title you'll come across something called the abstract the abstract is a short version of the paper giving just the highlights the nice thing about an abstract is it is often before the paywall that we talked about in the last lecture so that's good but as you can see it's very short you don't get all the details the abstract tells you various things and different journals structure their abstracts in different ways but often they'll give you some sense of the importance or the background of the issue that they're talking about the design or the methods of the trial the results or the outcomes and some final conclusion we'll touch on each of those aspects because they mirror something inside the paper itself now all papers are going to start with a background or introduction or some statement about what is important why are we doing this study in the first place it should say why does this study matter what context do we have going in what was the primary hypothesis okay so this is a this was a study looking at the use of improvisational music therapy on generalized social communication skills of children with autism spectrum disorder so in their background they say specifically the objective of this study was to evaluate effects of improvisational music therapy on generalized social communication skills of children with autism spectrum disorder i really like this at the end of the background section i like to hear why are you doing this what is the objective what is the purpose of this study and if there's a specific hypothesis what was that specific hypothesis what would we say in our water drinking study well we might say water to the extent of current knowledge is critical for the development and sustaining of all life on earth we set out to determine if drinking water would reduce perceptions of thirst among a healthy but thirsty population okay so we are saying in the background why water is important why it's important that we study this and what our main objective was to see if we can reduce thirst we then from the background we've sort of convinced the reader hopefully why they should be reading this in the first place we get to the methods and this is the part that i'll be honest most people kind of skip over they tend to just say oh this is all statistical nonsense but methods are really important it tells you who was enrolled in the study why they decided to enroll them exactly how they did those various measurements and how they compared them to each other so this was a a a study that looked at the effect of intervening on individuals while they were at the barber shop to help control their blood pressure and what you can see in the trial population part of the methods is they're telling you exactly how they found these people field interviewers screen the clientele at participating black-owned barber shops to recruit self-identified regular patrons greater than one haircut every six weeks for six months who are non-hispanic black men 35 to 79 years of age with systolic blood pressure of 140 millimeters of mercury or more so on and so on and so on they're giving you in theory enough detail that you can recapitulate the entire study on your own a good method section will leave no question about how any of it was done what are the real nuts and bolts so you get a description of the study the inclusion and exclusion criteria that's what people are allowed to be in the study and what people are not allowed to be in the study a detailed description of the intervention detailed description of the outcome okay your job just like the titles jobs to tell you what the exposure and the outcome is and the methods you should be very clear what the primary outcome is most medical studies will look at multiple things oh how did this affect people's physical performance how did it affect their pain levels how did it affect their social function etc but studies should identify a primary outcome the number one thing that they are really interested in they should tell you with the phrase primary outcome what that outcome is in the methods section in theory everything you need to recapitulate the study so in our water study we might say in our methods section water was provided in eight ounce cup solo comp company lake forest illinois right so we'd have a bunch of methods but we'd specify exactly what we did so that someone could do the same study if they wanted to now results are where things start to get interesting okay and what i'm showing you now is a study that looked at uh that looked at marathon runners um and their outcomes in terms of kidney function kind of an interesting study to me who's a kidney doctor but one thing i want to point out is the results just tell you what the measurements were there should be no editorializing there should be no hypothesizing why a result is something it is purely to give you the data the most one of the most important parts of the results section is table one and table one traditionally in almost every medical manuscript describes the population what are the characteristics of the people who enrolled in this study and so you can see these marathon runners were about 44 years of age and they were 41 male and they had a certain height and weight and there were very few people with type 1 diabetes and so on and so forth when you look at table 1 you're asking yourself does this look like me or does this look like people i care about would anyone i know be in this study or is this a very strange population right if the entire study was recruited from an island in the middle of the south pacific whatever the results are no matter how compelling you might reasonably ask yourself well is this going to make a difference in my life because i'm not a middle of the south pacific islander so always pay close attention to table 1. the results are also going to give you the outcomes in both groups but again no editorializing about why the outcomes are different in our water study we might say the average age of the grad students was 20 plus or minus three years and 60 percent were male the baseline thirst score was five uh plus one to two uh plus or minus one or one to two in both groups okay so we we we are giving just the raw data this is who participated in our study now you'll often see figures that look like this i'm picking a study here to show you that looked at the difference in hair regrowth in a trial comparing minoxidil to finasteride so that's rogaine the kind of thing you rub on your hair to finasteride a pill you can take to to grow hair i am not saying this is of any personal interest but it is a study that i paid some attention to and the results are going to give you that primary outcome in this study who grew more hair the people that got one drug or the people that got the other drug and you can see here they break it down into no change minimal hair loss minimal hair growth moderate hair growth and so on and so forth they're giving you the data they're not commenting on it yet they're not telling you necessarily why they think one works better than the other in our water study we might say after drinking mean thirst declined by three points in the water group compared to zero points in the control group and we'd have this little statistical artifact here called a p-value which we'll be talking about in a future lecture so we're just given the primary outcome results now discussion is the wild west that's where the authors are speculating about what they what the results were and what they mean so you've got to take discussions with major grains of salt okay so this was a study looking at acupuncture versus sham acupuncture among children among individuals sorry adults with chronic low back pain okay and the results just present the pain scores and whatnot and what you can see in the conclusion statement is this our findings provide further evidence that patients with chronic low back pain who receive acupuncture experience clinically relevant benefits compared with patients receiving no acupuncture treatment however the results also suggest that the correct location of needles plays only a limited role now what are they talking about well in their results you get this graph they showed that the improvement in back pain was about this high for regular acupuncture and only a tiny bit lower for sham acupuncture and then the people who got no treatment didn't get much better at all so the real way to interpret this data is to say that you know the act of sticking needles in someone kind of regardless of where you put the needles makes them feel subjectively better it doesn't argue that acupuncture in terms of manipulating energy fields or anything like that is true and yet the authors talk about this data as if acupuncture has been shown to do something special when really if sham acupuncture is the same as true acupuncture it kind of argues that the specialness comes maybe just from being in a darkened room while someone pokes at you a little bit rather than any sort of more ancient or traditional magic so be careful when you read a discussion in our water study we might say something in our discussion like what are significantly reduced perceptions of thirst among these thirsty grad students suggesting that water should be the gold standard treatment for thirst in this population so what did i just do i showed i talked about our results but then i i went one step further i said water should be the gold standard treatment for thirst i don't have specific evidence of that i just showed it reduced your thirst maybe gatorade is better i don't know we didn't measure gatorade we didn't measure that effect so be careful of discussions don't take people's words for it okay this is where you get to spin spin your results a little bit so now that you know all the different parts of a paper we're going to do a quick quiz and see if you can assign these individual sentences to a certain paper section so how'd you do you know where everything goes all right so your take-home points for today a medical manuscript follows a set of rules that you now know you know where everything goes methods and results those two sections are objective and are basically trustworthy unless the researchers are being pretty nefarious but the background and the discussion and even the conclusion are potentially subject to a bit of spin so when you're reading those sections you can trust what they say but verify a little bit and use your skeptical hats when you're reading those sections that's it i'll see you next time