It is recommended that the high-risk medication Case Finding indicators listed in Appendix E of this guideline are used as a basis to monitor the effect of polypharmacy medication reviews. Given the large number of indicators, it is impractical to consider each indicator separately. The following strategies can be used to reduce the number of drug utilisation measures used:

• Measure the average number of high-risk medication Case Finding indicators triggered per person in the target population (as defined in Section 1 of this guideline, with further detail in Appendix E)
• Measure the proportion of patients triggering on any high-risk Case Finding medication indicator (overall composite)
• Measure the proportion of patients triggering on any high-risk Case Finding medication indicator targeting the same adverse event (event specific composites)

17 of the drug utilisation measures that can be used for both Case Finding and Clinical Outcomes are established indicators. In Scotland the National Therapeutic Indicators provide prescribing measures, which are closely related to the high-risk medication Case Finding indicators, and may be used to monitor Clinical Outcomes. A clear advantage of taking this approach is that they are mostly already built into the GP clinical systems, prescribing support tools and national dashboards.

The Information Services Division (ISD) prescribing team have produced standard reports on these indicators, which are available to authorised Prescribing Information System (PIS) users and will enable them to run summary and comparator reports.  For further details please go to: http://www.isdscotland.org/Health-Topics/Prescribing-and-Medicines/Community-Dispensing/Polypharmacy/ or contact nss.isdprescribing@nhs.net

An example of the dashboard which will be available to authorised PIS users is shown on the next page. The example show the number of patients ≥ 65 years prescribed a NSAID, ACEI/ARB and a diuretic. The dashboard show time series data showing the changes between  Q3 of 2012  and Q3 of 2017.

Hospitalisation data is routinely collected at national level in the Scottish (SMR01) record. Although the outcome of interest are hospital admissions that are explicitly drug-related (which is unfeasible to measure at national scale), for some types of hospital admissions, a drug-related aetiology may be sufficiently common to attribute the admission to that cause. Improvements in drug utilisation may be reflected in an overall reduction in these admissions among those targeted for polypharmacy medication reviews. Although the specific criteria used by different health boards to prioritise patients for review may differ, it is suggested that outcomes are measured among the subpopulation of patients aged 75 years older. Since the case finding criteria (nursing home residents, those on 10 or more drugs and those triggering high-risk medication indicators) are most commonly met in this subpopulation, and any effects of polypharmacy medication reviews are therefore likely to be most visible. The following Clinical Outcome hospital admission measures are recommended.

Proportion of patients 75 years or older with an emergency admission for:

• gastro-intestinal bleeding
• bleeding of any cause
• heart failure
• acute kidney injury
• falls and fractures
• stroke
• delirium
• clostridium difficile infection
• hypoglycaemia
• hyperglycaemia
• asthma
• COPD

Combining the measurement of specific types of hospital admissions with drug utilisation patterns may enhance the interpretation of any observed changes. For example, if a reduction in hospital admissions for gastro-intestinal bleeding was accompanied by a reduction in the prevalence of patients triggering high-risk medication use indicators targeting gastro-intestinal events, this would increase the confidence that the observed changes in clinical outcomes are attributable to improved medication use processes.

All plausibly beneficial health care interventions have the potential to have unintended consequences. Where such potential consequences can be identified, it is good practice to measure them to enable a balanced accounting of intervention effects. As part of polypharmacy medication reviews, patients and practitioners are encouraged to have informed discussions about omitting, discontinuing or de-intensifying prophylactic treatments (such as blood pressure lowering or antidiabetic treatment) that have doubtful benefits over the patient’s likely remaining life span. The following balancing measures are therefore recommended to provide reassurance that reviews do not adversely impact on the incidence of cardiovascular events.

Among patients 75 years or older:

• the proportion of patients with an emergency hospital admission for myocardial infarction
• the proportion of patients with an emergency hospital admission for stroke
• the proportion of patients with an emergency hospital admission for diabetes/hyperglycaemia

In addition to reductions in specific hospital admissions it is possible that polypharmacy medication reviews also impact on unscheduled health care utilisation more generally. However, ‘all cause health care utilisation’ may be more commonly influenced by non-drug-related causes and it is therefore likely to be a measure that is less responsive to the impact of polypharmacy medication reviews than hospital admissions for commonly drug-related causes. Nevertheless, the following outcome measures may usefully supplement the outcome measures specified in sections 1.1 and 1.2:

Among patients 75 years or older:

• the proportion of patients with an emergency hospital admission of any cause
• the number of unscheduled occupied bed days
• the proportion of patients discharged into dependent care