When Ovid won't map to a known MeSH term

OK, here is a weird thing. If you search "documentaries and factual films" in Ovid (note the quotes to deal with the "and"), you will receive the notice: Ovid was unable to map your term 'documentaries and factual films' to a subject heading.

However, this term is definitely a MeSH term. You can find it in the MeSH database (it is a Publication Type), and it has been called this since 2008 (it was called something else 1997-2008).

Weird! Since it is a publication type, we tried searching "documentaries and factual films".pt. in Ovid, and got zero results. Which was a clue, but we didn't know it at the time.

We then thought, OK, we'll search it in PubMed, and find an article, and then look at the Complete Reference for that article.

However, when we searched it in PubMed, it turned out that there were zero results. Not a single document has been labelled with this publication type since 1997!

(Which kind of made us wonder why it is a publication type at all. I mean, why is this a publication type and systematic review is not a publication type?!? But I digress...)

And this explains Ovid's behaviour too. Although the exact algorithm that Ovid uses is proprietary, it's generally known that Ovid takes the term you enter, looks for it in an unknown set of fields in the articles in its database, and then returns the most prevalent MeSH terms in the articles containing that term. Since this is a MeSH term that has never been used, and the phrase is stilted enough that apparently it doesn't appear in any titles and abstracts either, no results were found.

Now, I presumed from some of Ovid's other behaviour, that it searched the MeSH database directly as well as looking for the phrase in the titles, abstracts, and indexing of individual articles. I thought that's why a search for public health returned public health but not public health surveillance and other terms containing the words "public health". I presumed that the algorithm found an exact match in the MeSH database and therefore stopped looking. However, if that were true, then this search would have returned exp "Documentaries and Factual Films"/ with zero results.

No, I think this means that a direct search in the MeSH database is not part of Ovid's mapping algorithm. Instead, I guess it does search of articles every single time, even if the entry is exactly the same as a MeSH term. Then, it must generate a list of potential MeSH, and then (get this!) it must delete all of the other found MeSH if there is an exact match. (Whaaat?!?)

Well, I'm sure that it makes sense to someone, somewhere.

Anyway, if you search a known MeSH in the Ovid interface and get an error message, try confirming in PubMed to see if there are zero results. BTW, typing exp "Documentaries and Factual Films"/ did not produce an error message. There were, of course, zero results.

Thanks to my colleague Robert for bringing this to my attention.

If you can't find any reviews...

My colleague Angela totally saved me today. I was doing this search on spinal/epidural anesthetics for C-sections, and all I could find was studies. Seriously, where were the reviews? It didn't seem possible that there were no reviews, and yet, I couldn't find any (in Medline).

My MeSH terms were: "Anesthesia, Spinal"[Mesh] OR "Anesthesia, Epidural"[Mesh]

Which seemed reasonable at the time, but there were no reviews.

Angela did the peer review on my search and was also surprised that there were no reviews. A few minutes later she came back with a Cochrane review exactly on topic. Whaaat?

So, it turns out that the Cochrane review was indexed with the broader term of the two MeSH that I used, which is "Anesthesia, Conduction"[Mesh]. I'd come across two other terms for this (regional and neuraxial) but not conduction, so I had assumed it was too broad.

I think this might be a bit like the rule of three situation that sometimes occurs. Anyway, I'm thinking that when there aren't many reviews for a topic which would seem to be a good one for reviews, a good strategy would be to check out some broader terms, since reviews tend to be broader in scope than studies.

I'll try it out a few times and report back whether it's a broadly applicable strategy or just applies in this instance.

Children

Apparently I don't have a blog posting for searching for info about children

This is useful when the limits ("Adolescent"[Mesh] OR "Child"[Mesh] OR "Infant"[Mesh])
 just aren't doing it for you. Which is kind of often, because of the whole "is 18 years an adolescent or an adult" thing, plus the whole reviews-don't-require-checktags thing.

If you're looking for everything you can find:

child[all fields] OR children[all fields] OR childhood[all fields] OR pediatr*[all fields] OR paediatr*[all fields] OR juvenile*[all fields] OR adolesc*[all fields] OR teen*[all fields] OR youth[all fields] OR boy[all fields] OR boys[all fields] OR girl[all fields] OR girls[all fields] OR infan*[all fields] OR newborn*[all fields] OR neonat*[all fields] OR toddler*[all fields] OR preschool*[all fields] OR pre-school*[all fields] OR school age*[all fields] OR elementary[all fields] OR high school*[all fields] OR secondary school*[all fields] OR grade school*[all fields] OR preteen*[all fields] OR pre-teen*[all fields] OR prepubescen*[all fields] OR pre-pubescen*[all fields] OR middle school*[all fields] OR schoolchild*[all fields]

If you're trying to narrow to just the pediatric-specific stuff:

child*[tiab] OR pediatr*[tiab] OR paediatr*[tiab] OR juvenile*[tiab] OR adolesc*[tiab] OR teen*[tiab] OR youth[tiab] OR boy[tiab] OR boys[tiab] OR girl*[tiab] OR infan*[tiab] OR newborn*[tiab] OR neonat*[tiab] OR toddler*[tiab] OR preschool*[tiab] OR pre-school*[tiab] OR school age*[tiab] OR elementary[tiab] OR high school*[tiab] OR secondary school*[tiab] OR grade school*[tiab] OR preteen*[tiab] OR pre-teen*[tiab] OR prepubescen*[tiab] OR pre-pubescen*[tiab] OR middle school*[tiab] OR schoolchild*[tiab]

For Ovid Medline:

(child* OR pediatr* OR paediatr* OR juvenile* OR adolesc* OR teen* OR youth OR boy OR boys OR girl* or infan* or newborn* or neonat* or toddler* or preschool*or pre-school* OR school age* OR elementary OR high school* OR secondary school* OR grade school* OR preteen* OR pre-teen* OR prepubescen* OR pre-pubescen* or middle school* or schoolchild*).ti,ab.

Mortality and Life Expectancy

Most important thing about mortality is to use the subheading. You will get lots more results with that. Really the other stuff gets superfluous, but we use it anyway just in case.

"Disease name/mortality"[Mesh] OR ("Disease Name"[Mesh] AND ("Mortality"[Mesh] OR "Life Expectancy"[Mesh] OR "Longevity"[Mesh] OR "Survival Rate"[Mesh] OR "Survival"[Mesh]))

if you can't do that:
mortality[subheading] OR "Mortality"[Mesh] OR "Life Expectancy"[Mesh] OR "Longevity"[Mesh] OR "Survival Rate"[Mesh] OR "Survival"[Mesh]

Don't use "Survival Analysis"[Mesh] because this is something else entirely.

EMBASE:

exp mortality/ or exp survival/ or exp longevity/ or exp lifespan/

Plus keywords:
(mortalit* or survival or longevit* or life span* or lifespan* or life expectan*).ti,ab.

And if you're really desperate:
(die or died or dying or death).ti,ab.

Leave off that first one if you're searching on deep infiltrating endometriosis, though. Because of the dumbest acronym ever.

Treatment beyond therapy

So, every once in a while I do a search using "therapy"[subheading], and get some results but not as many as I wanted. Then I have the "bright" idea of trying some other MeSH terms. I mean, maybe sometimes the indexers forget to put therapy as a subheading, or maybe the rule of three applied, or something like that. Right?

So, then I go through a labourious process of finding other relevant MeSH. Basically this involves thinking of treatments and searching them in the MeSH database and then looking at the broader terms.

Here's what I come up with:

"Treatment Outcome"[Mesh] OR "Therapeutic Uses"[Mesh] OR "Pharmaceutical Preparations"[Mesh] OR "Therapeutics"[Mesh] OR "Mental Health Services"[Mesh] OR "Psychiatric Somatic Therapies"[Mesh] OR "Psychotherapy"[Mesh]

So then I take that and combine it with the rest of my search, and use NOT to get rid of the "therapy"[subheading] articles which I've already looked at.

Guess what? So far, every single time, it's added nothing to the search. This time, I got a couple of articles about chemicals which are used as therapies but are also endogenous compounds, and in this case there are some articles about how their regulation affects the disease. Fits the search strategy, but completely irrelevant.

But who knows, in a few months I'll probably try it again. Einstein had a saying about this kind of behaviour...

College/University Students

Medline:

"Students"[Mesh]
Narrower terms are "Student Dropouts" and "Students, Health Occupations" - nothing about the level. You might wish to NoExp on the Students part if you're interested in college/university students in general rather than medical or nursing students.

There's also "Student Health Services"[Mesh]

Combine with:

"Universities"[Mesh] OR colleg*[tiab] OR universit*[tiab] OR postsecondary[tiab] OR post-secondary[tiab] OR undergraduate*[tiab] OR campus*[tiab] OR graduate[tiab] OR postgraduate*[tiab] OR post-graduate*[tiab] OR "higher education"[tiab] OR tertiary[tiab]


CINAHL:

MH "Student Health Services" OR MH "Students" OR MH "Students, Disabled" OR MH "Students, Foreign" OR MH "Students, Minority"
AND
MH "College and Universities+" OR TI (universit* OR postsecondary OR post-secondary OR undergraduate* OR campus* OR graduate OR postgraduate* OR post-graduate* OR "higher education" OR tertiary) OR AB (universit* OR postsecondary OR post-secondary OR undergraduate* OR campus* OR graduate OR postgraduate* OR post-graduate* OR "higher education" OR tertiary)
OR

MH "Students, College" OR MH "Students, Graduate+" OR MH "Students, Undergraduate"

You may or may not wish to include:

MH "Students, Health Occupations+" OR MH "Students, Pre-Nursing"

Breast Cancer Hormone Receptors

I recommend searching this in Ovid Medline to make use of adjacency searching.

Estrogen receptor positive:

(estrogen receptor positive or oestrogen receptor positive or er positive or er+ or estrogen receptor +ve or oestrogen receptor +ve or er +ve).mp.
(estrogen receptor adj2 positive).mp.
(oestrogen receptor adj2 positive).mp.

If you don't have access to Ovid Medline, substitute this for the adjacency searches:

"estrogen receptor positive"[tiab] OR "oestrogen receptor positive"[tiab] OR "estrogen receptor alpha positive"[tiab] OR "oestrogen receptor alpha positive"[tiab]

Estrogen receptor negative:

(estrogen receptor negative or oestrogen receptor negative or er negative or er- or estrogen receptor -ve or oestrogen receptor -ve or er -ve).mp.
(estrogen receptor adj2 negative).mp.
(oestrogen receptor adj2 negative).mp.

For PubMed:
"estrogen receptor negative"[tiab] OR "oestrogen receptor negative"[tiab] OR "estrogen receptor alpha negative"[tiab] OR "oestrogen receptor alpha negative"[tiab]

Progesterone receptor positive:

(progesterone receptor positive or pr positive or pgr positive or pr+ or pgr+ or progesterone receptor +ve or pr +ve or pgr +ve).mp.
(progesterone receptor adj2 positive).mp.

Progesterone receptor negative:

(progesterone receptor negative or pr negative or pgr negative or pr- or pgr- or progesterone receptor -ve or pr -ve or pgr -ve).mp.
(progesterone receptor adj2 negative).mp.

Human epidermal growth factor positive:

(human epidermal growth factor adj3 positive).mp.
or
(her2 positive or her2-neu positive or erbb2 positive or her2+ or "her2/neu+" or erbb2+ or her2 +ve or her2-neu +ve or erbb2 +ve).mp.

Human epidermal growth factor negative:

(human epidermal growth factor adj3 negative).mp.
or
(her2 negative or her2-neu negative or erbb2 negative or her2- or "her2/neu-" or erbb2- or her2 –ve or her2-neu –ve or erbb2 -ve).mp.

Additional, more general keywords:

(hormone receptor positive or hr positive or hormone receptor double positive or estrogen receptor progesterone receptor positive or er+pr+ or er+pgr+ or hormone receptor +ve or hr +ve or luminal a or luminal b or normal like).mp.
(hormone receptor adj2 positive).mp.

May be relevant depending on the specific question:

(triple negative or basal like).mp.

(her2 enriched).mp.

Definitions:

Luminal A: ER+PR+HER2-, low levels of Ki-67
Luminal B: ER+PR+, HER2 either + or -, high levels of Ki-67
Triple negative: ER-PR-HER2-
HER2 enriched: ER-PR-HER2+
Normal-like: ER+PR+HER2, low levels of Ki-67