Pain scales: VAS, numeric, faces and PAINAD, which to use and when

Why pain is measured with a scale

Pain does not show up in a blood test or on a monitor. What there is, is what the person says, and what the team observes when the person can no longer say it. Pain scales put that into a record that someone else on the team can read the same way on the next shift.

In Portugal, Circular Normativa no. 9/DGCG from the Directorate-General of Health, dated 14 June 2003, made pain the 5th vital sign. It asks for pain intensity to be recorded systematically with one of four validated scales: the visual analogue scale, the numeric scale, the verbal rating scale or the faces scale. It also sets two rules that are still at the heart of it all: intensity is what the person reports, and each patient should always be assessed with the same scale.

Visual analogue scale (VAS)

The visual analogue scale is a 10 cm line. One end reads "no pain", the other "worst pain". The person marks the point that matches their pain, and the distance from the start of the line is measured.

Its advantage is that it does not force a number, and some people find pointing easier than counting. Its limits are just as clear. It needs paper or a ruler, good eyesight and enough dexterity to make a mark. For the record, the Portuguese circular converts it into a numeric score.

Numeric pain rating scale

On the numeric scale, the person gives their pain a number from 0 to 10, where 0 is no pain and 10 is the worst pain imaginable. It is one of the most used because it can be done out loud, at the bedside, with nothing at all, and the number goes straight into the record.

Its weak point is abstraction. Asking for "a number from 0 to 10" from someone very tired, anxious, with little schooling or with mild cognitive impairment does not always give an answer that means the same thing from one time to the next. In those cases it is worth changing scale, and then keeping the new one.

Verbal rating scale

The verbal rating scale asks the person to choose a word: no pain, mild, moderate, severe or worst pain. It is less fine-grained than the numeric scale, but many people answer a word with more confidence than a number, older people especially. For those who use it every day the rule is the same as for the others: always the same words, in the same order.

Faces pain scale

A faces pain scale shows a row of drawn faces, from a calm face to one in the worst pain, and the person points to the one that fits. The best known are the Faces Pain Scale-Revised (FPS-R), with six faces scored 0, 2, 4, 6, 8 and 10, and the Wong-Baker scale.

They were designed for children, who are not yet comfortable with numbers, but they are also used with adults who find reading or abstraction hard. It helps to explain first that you choose the pain you feel, not the face you are making. A frightened child with no pain may point to a sad face, and that is information for the team too, just a different kind.

When the person can no longer say it: PAINAD

All the scales above are self-report, and the Portuguese circular itself says they apply to conscious, cooperative people over 3 years of age. That leaves out people with advanced dementia, people who are very confused and people who no longer speak. That is where pain is most easily missed.

The PAINAD scale was developed for these situations (Warden, Hurley and Volicer, 2003). The rater observes the person for a few minutes and scores five signs from 0 to 2: breathing, negative vocalisation, facial expression, body language and consolability. The total runs from 0 to 10. There is a European Portuguese version, adapted and studied in 99 older inpatients with or without dementia.

The PAINAD does not diagnose the cause of pain. It shows that there are signs worth attention, and it is most useful when repeated: before and after a change of position, a dressing, a painkiller. We wrote more about this in pain in dementia, when the person does not say it hurts.

How to choose

No scale is better than the others. There is the one that suits that person, at that moment:

• Speaks, understands numbers and is cooperative: numeric scale, or VAS if they prefer to point.
• Speaks, but numbers confuse them: verbal rating scale or faces scale.
• A child: faces scale, with the right explanation first.
• Can no longer say they are in pain: an observational scale, such as the PAINAD.

Once chosen, the scale stays the same for that person. Switching scales halfway makes it impossible to compare one record with the next, which is exactly what measuring is for.

Where RVer fits

RVer is used as a non-pharmacological complement during procedures, in moments of anxiety and through long days on a ward or in a care home, always with the team close by. It does not measure pain and does not replace clinical assessment. When a team wants to see whether a session helps a patient manage pain or anxiety, the way to see it is the usual one: the same scale, before and after.

For hospital settings, see the solution for hospitals and clinics; for care homes, the one for care homes and residential care. On needle procedures, we have an article on virtual reality for fear of needles and procedures.