A valuable tool for research in clinical literature

by 184yw8rhwhr
July 26, 2024

«Go later PICO scheme This is the recommendation of many reviewers and reviewers, as well as some regulatory documents (such as the MDCG and MEDDEV 2.7/1 rev.4 guidelines) when it comes to precise searches of medical literature.

Read in this article,

what is PICO scheme and what variations you should know,
in which tasks (even apart from bibliographic research) does the PICO scheme help you e
how to successfully create and apply a PICO scheme.

1. PICO scheme: basics

Fig. 1: The PICO scheme is an acronym for the most important aspects of a literature search.

1.1 Definition

The PICO framework is a tool for identifying key concepts in a topic and structuring literature reviews. It is used for topics that involve an intervention or treatment.

The topic is structured according to four aspects:

	I wait	Explanation
P	Patient/Population	Description of the patient group or problem
I	Intervention	Description of the main intervention or treatment
C	Comparison	Alternative treatment or control group
OR	Result	Desired outcome or target variable

Table 1: Explanation of the PICO scheme

1.2 Example

Case 1: Search of specialist literature

Your task is to research the relevant specialist literature for a heat pack, for example to determine the state of the art.

The intended purpose of this product states:

“Thermal compress for the treatment of back pain. The heat pack maintains a temperature of 40°C for 8 hours. It applies therapeutic heat deeply, thus relieving muscle tension and stimulating blood circulation in the tissues. The pain is reduced.”

From this purpose the following aspects can be adopted:

P	Patients with back pain
I	Heat compress, deep therapeutic heat, heat application, heat therapy
C	—
OR	Pain reduction

Table 2: Incomplete PICO scheme for thermal package example

In this example, aspect C (Comparison) is not considered.

Case 2: Evaluation of a comparative therapy

Your question refers to comparative therapy and is as follows:

“Is using a heat compress more effective than taking 1,200 mg of ibuprofen per day?”

This results in the complete PICO scheme. The aspects for the study of the thermal pack are:

P	Patients with back pain
I	Heat compress, deep therapeutic heat, heat application, heat therapy
C	1200 mg Ibuprofen, NSAR
OR	Pain reduction

Table 3: Completed PICO diagram for the thermal package example

1.3 Variants

Depending on the application and context, PICO can be expanded to include additional components.

1.3.1 PEAKS

The “S” add-on stands for Study Design. PICOS incorporates study design to narrow the search, e.g. B. on randomized controlled trials (RCTs), observational studies or systematic reviews.

PICOS aspects for an expanded thermal package study could be:

P	Patients with back pain
I	Heat compress, deep therapeutic heat, heat application, heat therapy
C	1,200 mg Ibuprofen, NSAR
OR	Pain reduction
S	Randomized controlled trials

Table 4: PICOS diagram for example of thermal package

1.3.2 PICOC

The add-on “C” indicates contextual factors, e.g. B. Patient comorbidities, environmental conditions, or settings that may affect results.

PICOC aspects for an expanded thermal package study could be:

P	Patients with back pain
I	Heat compress, deep therapeutic heat, heat application, heat therapy
C	1,200 mg Ibuprofen, NSAR
OR	Pain reduction
C	Chronic pain, frequent sedentary lifestyle, age > 75 years

Table 5: PICOC diagram for example of thermal package

1.3.3 Other variants

In addition to PICOS and PICOC, there are other extensions and variants developed for special fields of application:

PIPOH (Population, Intervention, Profession, Result, Healthcare context) for questions on the quality of care
SPIDER (Sample, Phenomenon of Interest, Design, Evaluation, Type of Research) for qualitative studies in nursing
PICO-D (Population, Problem, Context, Study Design) for psychological issues

The choice of the appropriate PICO variant depends on the specific question and information needs.

The more precise the question, the more focused the search will be and the less effort will be needed to evaluate the literature.

2. Scopes of application of the PICO scheme

2.1 Bibliographic research

People working in scientific fields such as doctors, clinical affairs managers, medical writers and pharmacologists mainly use the PICO scheme to find clinical literature quickly and accurately.

These bibliographic searches are necessary for the approval of drugs and medical devices in the context of clinical evaluation:

The PICO scheme is used to formulate search strings for the search masks of scientific databases. PICO is therefore used at the very beginning of the literature search, particularly when the strategy for the literature search is developed.

2.2 Evidence-based medicine

In evidence-based medicine, the PICO framework helps answer evidence-based questions such as:

Is drug A more effective than drug B in treating disease
Does minimally invasive surgery produce better results than open surgery in patients with disease Y?
Does Z vaccination reduce the risk of W infection in children compared to no vaccination?
Is test A more accurate than test B in diagnosing disease V?
Does a specialized rehabilitation program improve mobility in post-stroke patients compared to standard rehabilitation?

The PICO scheme is also used in evidence-based medicine to make recommendations or create medical guidelines.

2.3 Formulate an expanded purpose

The PICO scheme is also useful in formulating the extended scope. It can be used, for example, as a “checklist” to check whether the intended scope covers all aspects.

3. Evaluation of the PICO scheme

3.1 Advantages

The PICO scheme has proven itself.

It is widely used and creates a shared mental model as a basis for collaboration.
It makes it easier to translate clinical questions into search terms and therefore helps to carry out bibliographic searches in a faster, more structured and more precise way.
It helps you get better (especially more relevant) search results faster.
Speeds up evaluation because fewer irrelevant sources need to be read, evaluated, and excluded.

3.2 Regulatory obligation?

There is no explicit regulatory requirement for using the PICO scheme. However, it is considered best practice in evidence-based medicine and recommended by many organizations.

When writing the clinical evaluation, manufacturers should consider relevant guidance documents such as MEDDEV 2.7/1 rev 4 and the MDCG guideline MDCG 2020-13. Both propose the PICO scheme. Therefore, many clinical evaluation researchers consider the PICO scheme mandatory and state-of-the-art.

3.3 Lack of alternatives(?)

Neither MEDDEV 2.7/1 rev 4 nor MDCG mention an alternative to the PICO scheme for the task of finding relevant keywords and search strings.

4. Creating a PICO scheme

To ensure you can successfully create and use the PICO scheme for your scientific research, please note the following:

4.1 Adapt the PICO scheme to the task

The following categories and classifications have been established:

State of the art research
- Purpose (= intervention)
- Indications (patient population)
- Generic product group (= no comparison)
- Clinical benefit/performance/safety (outcome)
Product search
- Name of your product
- Company Name
Search for reference products
- Name of similar/equivalent product
- Name of the associated company

4.2 Database search in five steps

Once you have identified specific keywords, you should do the following:

Identify question/purpose
Identify synonyms by category
Translate it into English (in scientific databases the language is English.)
Connect synonyms within a category with the Boolean operator OR and place them in parentheses
Connect the categories with AND

This creates a search string that is used in search forms of databases such as PubMed, Embase or Cochrane for bibliographic searches.

Example: Search string for Hotpack

P	Patients with back pain
I	Heat compress, deep therapeutic heat, heat application, heat therapy
C	—
OR	Pain reduction, VAS score
Back pain AND (hot compress OR therapeutic heat OR heat application OR heat therapy) AND (pain reduction OR VAS score)

Table 6: Interaction between PICO and the database query string

4.3 The most common errors

Typical errors when using PICO schema and database lookup are:

The wrong Boolean operators are used.
The brackets are positioned incorrectly.
Inappropriate keywords are used, such as product specifications that are not detailed in publications.
Inconsistencies arise between the PICO elements and the actual research question.
PICO is used in the wrong context, e.g. B. in security databases.

Too many results in the literature search (> 1,000) or too few results (< 5) may be an indicator that the PICO scheme has not been applied correctly.

4.4 Further suggestions

The following approaches have proven effective:

Use precise and specific terms.
Consider relevant synonyms for each PICO component.
If necessary, adapt the scheme to the specific question (e.g. PICOT or PICOS).
Use “Advanced Search” in PubMed, which supports bracketing and Boolean operators.
When looking for synonyms, use medical dictionaries, well-known publications in the field, and the mesh database on PubMed.

4.5 Use the support

The scientific and clinical experts at the Johner Institute will help you with all tasks related to clinical evaluation and post-market clinical follow-up, e.g. B. from:

Review of your PICO scheme
Review of your literature research
Bibliographic research laboratory; The application of the PICO scheme is explained and demonstrated in detail here
Creation of the PICO scheme and conduct of bibliographic research

Simply contact us, for example via Contact pageif you need help or want advice.

5. conclusion

The PICO scheme is a proven and indispensable tool for formulating research questions and scientific investigations.

For medical device, IVD and pharmaceutical manufacturers, PICO especially supports all scientific and medical experts.

The PICO scheme and its variants constitute the state of the art.