Self-monitoring of blood pressure in patients with hypertension related multi-morbidity: Systematic review and individual patient data meta-analysis.

Sheppard, J P; Tucker, K L; Davison, W J; Stevens, R; Aekplakorn, W; Bosworth, H B; Bove, A; Earle, K; Godwin, M; Green, B B; Hebert, P; Heneghan, C; Hill, N; Hobbs, F D R; Kantola, I; Kerry, S M; Leiva, A; Magid, D J; Mant, J; Margolis, K L; McKinstry, B; McLaughlin, M A; McNamara, K; Omboni, S; Ogedegbe, O; Parati, G; Varis, J; Verberk, W J; Wakefield, B J; McManus, R J

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. Randomised controlled trials of self-monitoring of BP were selected and individual patient data (IPD) were requested. Contributing studies were prospectively categorised 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 mmHg, [95%CI -4.78, -1.46 mmHg]; 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.