BACKGROUND

Studies have shown that self-monitoring of blood pressure
(BP) is effective when combined with co-interventions, but its efficacy varies
in the presence of some co-morbidities. This study examined whether
self-monitoring can reduce clinic BP in patients with hypertension-related
co-morbidity.

METHODS

A systematic review was conducted of articles published in
Medline, Embase, and the Cochrane Library up to January 2018. Randomized
controlled trials of self-monitoring of BP were selected and individual patient
data (IPD) were requested. Contributing studies were prospectively categorized
by whether they examined a low/high-intensity co-intervention. Change in BP and
likelihood of uncontrolled BP at 12 months were examined according to number
and type of hypertension-related co-morbidity in a one-stage IPD meta-analysis.

RESULTS

A total of 22 trials were eligible, 16 of which were able to
provide IPD for the primary outcome, including 6,522 (89%) participants with
follow-up data. Self-monitoring was associated with reduced clinic systolic BP
compared to usual care at 12-month follow-up, regardless of the number of
hypertension-related co-morbidities (−3.12 mm Hg, [95% confidence intervals
−4.78, −1.46 mm Hg]; P value for interaction with number of morbidities = 0.260).
Intense interventions were more effective than low-intensity interventions in
patients with obesity (P < 0.001 for all outcomes), and possibly stroke (P
< 0.004 for BP control outcome only), but this effect was not observed in
patients with coronary heart disease, diabetes, or chronic kidney disease.

CONCLUSIONS

Self-monitoring lowers BP regardless of the number of
hypertension-related co-morbidities, but may only be effective in conditions
such obesity or stroke when combined with high-intensity co-interventions.