Measuring blood pressure

Hierarchy of blood pressure measurement for diagnosis of high blood pressure in primary care

General considerations for BP measurement

1. Office/Surgery BP measurement* is fine for opportunistic screening (reassuring if normal but beware of false positives)
2. AOBP (Automated Office/Surgery BP) measurement)* is more reliable and preferred to surgery measurement for initial screening (but needs a room; see below)†
3. HBPM (Home BP Monitoring) is valuable for diagnosis (see indications for ABPM)
4. ABPM is the gold standard for diagnosis (and recommended by NICE)

Least reliable                \(\rightarrow\)                   Most reliable      

Office/Surgery  \(\rightarrow\)  AOBP  \(\rightarrow\)  HBPM  \(\rightarrow\)  ABPM

* Office and/or AOBP could be unncessary if HBPM is available

† AOBP involves fitting the individual with an automated monitor, sitting them in a quiet room, asking them to sit quietly and not read or use their phone, and then leaving them alone for around 5 minutes while the BP monitor make several automated measurements.

Indications for ABPM rather than HBPM in diagnosis:

This is available at WGH, RIE and SJH

1. Assessment of nocturnal BP values and dipping status. This should be normal practice for people with:

• Chronic kidney disease
• Diabetes mellitus (Type 1 or 2)
• Sleep apnoea
• Endocrine hypertension
• Autonomic dysfunction

2. Borderline HBPM (where ABPM refines risk)
3. Unable to perform HBPM or gets unreliable results
4. Anxiety about doing HBPM/seeing the results

Follow-up of people with high BP

1. Generally, HBPM will be suitable for follow up of patients with high BP, unless there is a poor correlation between HBPM and ABPM or there is a contraindication to HBPM (see above).
2. Surgery BP measurement is not a reliable way to follow up patients with high BP.
3. If HBPM cannot be provided by the surgery, reliable affordable BP monitors can be purchased by for around £15 (see: Validated BP Monitors for Home Use)