Implementation and dissemination WHO regional and country offices, through their contacts with ministries of health, will encourage implementation at country level. WHO will provide technical assistance if substantial country adaptation is required. The HEARTS technical package, which is currently being implemented in 18 countries and has significant partner endorsement, membership and engagement, will be the platform used to implement and disseminate this guideline. The package will be revised to include the implementation tools from this guideline. Separate implementation aspects are being considered as implementation or derivative tools for nonphysician treatment and the treatment of hypertension in areas of humanitarian crises, following publication of the guideline. Implementation support will be extended to countries through all three levels of WHO. 5.3 Evaluation WHO will monitor uptake and implementation of the guideline in national policies and programmes by reviewing the number of countries that have adapted or endorsed the guideline nationally. 5.4 Future updating of the guideline The guideline is expected to be valid for a period of five years. This period reflects the fact that new research findings are likely to become available in the meantime but also represents a feasible time frame, considering the costs, time and other resources that are needed for the updating process. If the evidence base or user needs change before the five-year mark, consideration will be given to producing updates sooner. 5.5 Research gaps Several research gaps were identified by the GDG according to the theme of the PICOs. Thresholds to determine initiation of therapy and targets to achieve for control [ More evidence is required regarding treatment of those in the SBP 130–139 range who fall into one or more of the following subgroups: diabetes, chronic kidney disease, heart failure, 65 years or older. [ There is a need for better outcomes data from, for example, trials that include heart failure and cognitive impairment among outcomes. [ Clinical significance of adverse events registered in clinical trials needs greater clarity. [ There is a need to quantify the difference in estimates between blinded, placebo-controlled trials and unblinded, active control trials using a standard framework. 24 [ There is a need for periodic analysis of trials in order to capture effects of changes over time in background epidemiology of CVD, non-BP treatments, competing risks, etc. [ More evidence is needed in LICs, MICs and other non-North American/European countries. [ An assessment of the feasibility, resource needs, and costs of intensive treatment in real clinical practice is needed. The resource commitment required for more intensive treatment in LMICs needs to be quantified.