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Text mining and NLP for health text

Extracting knowledge from unstructured text: scientific abstracts, clinical documentation, intervention records and research corpora

What it is

A natural language processing service for health and scientific text. It covers lexicon-based sentiment analysis, topic modelling to uncover latent themes, and document classification.

It applies to abstracts from bibliographic databases, text records of health interventions, clinical trial documentation and any text corpus holding unstructured health information that lends itself to quantitative analysis.

Objectives

  • Turn large volumes of unstructured text into quantifiable categories, themes and metrics that feed subsequent statistical analyses.
  • Uncover thematic patterns in document corpora that neither individual reading nor keyword search can reveal.
  • Quantify the emotional or thematic orientation of a corpus to complement bibliometric, infodemiological or implementation analyses.
Key points

Sentiment analysis of scientific and health text

  • Emotion classification with validated sentiment lexicons (NRC for Plutchik's eight emotions, Bing for positive/negative polarity).
  • Sentiment analysis by temporal, geographical or thematic subgroup to detect shifts in the orientation of the discourse.
  • Visualisation with emotion radar charts, stream plots and word clouds segmented by sentiment.

Topic modelling to uncover latent themes

  • LDA (Latent Dirichlet Allocation) models, with the number of topics selected by coherence and perplexity.
  • Extraction of document-topic and topic-term distributions for unsupervised classification of the corpus.
  • Applicable to bibliographic abstracts, text records of interventions (barrier-cause-strategy triads) and clinical documentation.

Text preprocessing and representation

  • Tokenisation, stop-word removal (standard + custom) and lemmatisation adapted to the health domain.
  • Construction of document-term matrices weighted by frequency and TF-IDF.
  • N-gram analysis and term co-occurrence networks to identify semantic associations.

Integration with statistical and research pipelines

  • NLP output as input for statistical analysis: text-derived variables (dominant topic, sentiment score) that can enter regression models, clustering or network analysis.
  • A complement to bibliometric analyses (sentiment and topics on the same corpus) and to implementation studies (automatic categorisation of barriers and facilitators).
  • Reproducible results in Quarto with documented code.

What it is for

  • Analyse the content of hundreds or thousands of abstracts from a literature search quantitatively, without reading them one by one, to identify emerging themes and the direction of the field.
  • Convert operational and patient-experience free text (records of interventions and care processes, field notes, open-ended answers to satisfaction surveys) into categories and metrics that complement the quantitative data.
  • Detect changes over time in the tone or subject matter of the research output on a topic, complementing classic bibliometrics with content analysis.
Why choose this service

You have data in text form, and you're treating them as if they didn't exist

In health research, a huge amount of information is trapped in free text: field observations, abstracts, incident records, clinical notes. Reading them one by one doesn't scale. Ignoring them wastes data you already have. Applied NLP turns that text into quantifiable variables that go straight into your statistical analyses.

From free text to statistical variables

The output of our NLP analyses is not a narrative report on what the text says. It is a set of numeric variables (dominant topic, sentiment score, assigned category) that go straight into regression models, network analyses or clustering as predictors or outcomes. The text stops being a qualitative appendix and becomes data.

Validated lexicons and unsupervised models, not hand-crafted rules

We use validated, published lexicons (NRC, Bing) for sentiment analysis and generative models (LDA) for topic modelling. We don't build ad hoc classification rules that only work on your corpus. The methods are replicable, publishable and defensible to reviewers.

Adapted to the health domain

Health text has technical vocabulary, abbreviations and structures that generic models handle poorly. We adapt the preprocessing to the domain: custom stop words for the field, handling of MeSH terms, and tokenisation that respects clinical and epidemiological terminology.

A service evolving with AI techniques

Today we offer lexicon-based sentiment analysis and topic modelling with LDA. We are adding techniques based on language models (embeddings, zero-shot classification, biomedical entity extraction) to extend what the service can do. The approach does not change: validated techniques applied to real health research problems, not experimentation with tools.

Our process

What working with us looks like

We apply our D²I (Data to Insights) methodology to every service. A structured, iterative and transparent process that turns complex data into actionable knowledge.

01

Kick-off and problem definition

We meet with you to understand the clinical problem, the data available and the objectives of the project. We agree on deliverables, timelines and communication channels, and we sign whatever confidentiality agreements you need to protect your data.

02

Data review and preparation

We assess the quality of your data, identify inconsistencies and limitations, and structure the data for analysis. If critical information is missing, we tell you before going any further. We document every cleaning decision so that the process is traceable and reproducible. In text mining and NLP, this includes defining the corpus (abstracts, text records, field notes), assessing the language and quality of the text, designing the preprocessing strategy (tokenisation, stop words, n-grams) and building the numerical representation of the text (DTM, TF-IDF) that will feed the models.

03

Analysis and modelling

We apply the statistical methodology that fits your questions. We work iteratively: we share preliminary results with you, discuss the findings and adjust the approach where needed. We do not work in the dark until the final delivery. For this service, we apply sentiment analysis with validated lexicons and LDA topic modelling with k selected by coherence, and generate text-derived variables for integration into downstream statistical pipelines. Each result is documented in Quarto with reproducible code and interpretable visualisations.

04

Communicating results

We turn the findings into the format you need: a technical report, tables and figures for publication, an interactive dashboard or an executive presentation. We always include the clinical interpretation, not just the figures.

05

Impact review session

30 days after delivery we meet with you again for a 60-minute strategy session. By then you have had time to present the results internally, the real implementation questions have come up and you can assess the impact of the work with some perspective. We answer your questions, adjust interpretations where necessary and agree together on the way forward.

This is our general process. If you want to understand how we apply it technically to each type of analysis, see our full D²I methodology.

Have a data project on your hands?

Tell us about your case and we will work out together how to approach it.

Book a session
FAQs

Frequently asked questions

I have a lot of unanalysed free text (abstracts, notes, records). What can I get out of it?

Quantifiable information: the service turns large volumes of unstructured text into categories, themes and metrics that feed statistical analyses. It applies when data are trapped in free text, such as abstracts from a literature search, intervention records, field notes or open-ended survey responses: text that is impractical to read item by item and goes to waste because it is not treated as data. On that corpus, the analysis identifies thematic patterns that neither individual reading nor keyword search can reveal, quantifies lexical, thematic or sentiment orientation, and derives variables that enter subsequent models. The text stops being a qualitative appendix and becomes a source of analysable variables. What the service provides is not a narrative summary of what the text says, but its conversion into metrics you can work with statistically.

What kinds of analysis do you run on the text?

Three main lines today: sentiment analysis, topic modelling and document classification, on a corpus that has been preprocessed and represented numerically. This applies if you need to characterise the content or orientation of a set of health or scientific documents. Sentiment analysis uses published, documented lexicons such as NRC or Bing, always checking that they suit the language, domain and aim of the corpus, rather than hand-crafted rules that only work on one particular corpus. Topic modelling uses LDA models, with the number of topics selected by coherence and perplexity, to propose latent thematic groupings without prior labelling. Before modelling, the text is preprocessed through tokenisation, removal of standard and custom stop words, and lemmatisation, and is represented as a document-term matrix weighted by frequency and TF-IDF. What you get are replicable, documentable methods that are more defensible under review than ad hoc rules.

Is the result a report describing the text, or something I can put into my models?

Variables and interpretive documentation, not just a narrative report: the output is a set of numeric metrics derived from the text, such as the dominant topic, the sentiment score or the assigned category, which go straight into subsequent analyses as predictors or outcomes. They come with the topic labelling, the term review and the preprocessing documentation needed to interpret them. This applies when the text has to be integrated with the rest of a study's quantitative analysis, rather than left as a separate qualitative appendix. These derived variables are fed into regression models, clustering or network analysis, so the content of the text becomes part of the statistical model as derived variables, with the caveats of the method that generates them. This makes it possible, for example, to relate a record's dominant topic to an outcome variable, or to use the sentiment score as a predictor. The work is documented in Quarto with reproducible code. What you receive is text converted into analysable data and integrated into the pipeline, not a description of what the text says.

My health text is full of technical vocabulary and abbreviations. Can you handle it, or do you struggle with it the way generic tools do?

The preprocessing is adapted to the health domain, precisely because generic preprocessing can mishandle its technical vocabulary, abbreviations and structures. This applies to health and scientific text corpora, where a generic treatment introduces noise or loses relevant terms. The adaptation includes custom stop words for the field, handling of controlled vocabularies such as MeSH where the corpus justifies it, and tokenisation that respects clinical and epidemiological terms, along with lemmatisation tuned to the domain. On that basis the representations are built, with a document-term matrix, TF-IDF, n-grams and term co-occurrence networks, which then feed the analysis. One point of scope: this adaptation applies to aggregated health text, such as abstracts, records or documentation, not to the quirks of a particular health record system. What you get is preprocessing that respects the domain's terminology, not a generic pipeline that treats it as noise.

Do you analyse individual health records? Do you extract diagnoses from each patient's notes?

No: the service is NLP on aggregated health and scientific text, such as abstracts, intervention records, aggregated clinical documentation, field notes or open-ended responses, not clinical NLP on individual health records. This limit needs stating because "health text" can be read both ways, and they are different jobs. What is out of scope: patient-by-patient extraction of clinical entities from individual records, using named entity recognition and coding to terminologies such as SNOMED-CT, which is a line of work with its own technical, ethical and data governance requirements. What is in scope: quantitative analysis of health and scientific text corpora to uncover themes, quantify orientation or derive variables. The boundary is clear: analysis of aggregated health text corpora, yes; mining of individual health records with NER and clinical coding, no. If you need that second line of work, you will find an explicit limit here, not a vague promise.

Is analysing text with NLP the same as doing bibliometrics?

No. Bibliometrics studies the literature as a field: who publishes, how authors and institutions are connected, and how the thematic structure changes; its result is a map of that field. Text mining examines the content of the corpus and turns it into variables, such as topics, sentiment or categories, that can be used in statistical analysis. Both can be applied to the same set of abstracts, but they answer different questions. If you want to understand how a scientific field is organised and evolving, you need bibliometrics; if you want to know what the texts say and quantify that content, you need text mining. When the question calls for both perspectives, we combine the bibliometric map with content analysis while keeping their conclusions distinct.

Do you use large language models and AI techniques such as embeddings or entity extraction?

Today the service relies on validated, published methods, such as lexicon-based sentiment analysis (NRC, Bing) and topic modelling with LDA; techniques based on language models are being incorporated and are not yet offered as an established capability. Being transparent about this matters, because the line between what is available and what is planned affects your decision. We are exploring and progressively incorporating techniques such as embeddings, zero-shot classification and biomedical entity extraction, which will extend the service's capabilities once they are validated. The criterion holds in both cases: validated techniques applied to real health research problems, not experimenting with tools for novelty's sake. If a project specifically requires one of those techniques, the scope should be defined case by case, according to how far the technique has been validated internally and how methodologically demanding the study is. What we offer today are the established methods; what is coming is described as what it is, ongoing development.

What do I need to provide, and what do I receive at the end?

You need the text corpus to be analysed, such as abstracts, text records, field notes or open-ended responses, with an indication of its language and context, so that the corpus can be defined and the preprocessing strategy designed. The client provides and owns the text; the service defines the corpus, assesses its language and quality, designs the preprocessing, builds the numerical representation, applies sentiment analysis or topic modelling and derives the variables. What you receive is the set of text-derived variables, such as the dominant topic, the sentiment score or the categories, ready to integrate into the statistical analysis, together with interpretable visualisations (of sentiment, thematic evolution and topic distributions) and the documented Quarto code that regenerates the result. What is delivered is text converted into reproducible data that fits into the study's pipeline, on a corpus that remains the client's.

Shall we talk?

Tell us what you are working on and we will give you a straight answer on how we can help.