Outcome measures

The ultimate aims of polypharmacy medication reviews are to reduce drug-related harm and to achieve therapeutic objectives in line with patients’ preferences, rather than simply reducing the numbers of medicines patients are taking. However, establishing whether clinical outcomes are attributable to drug therapy or other underlying causes is not realistically possible at scale, and monitoring of the effect of polypharmacy medication reviews therefore requires the use of proxy outcome measures that can be implemented in routine data sources available at national level. These measures fall into two categories: drug utilisation and hospital admissions

 

Clinical Outcome - drug utilisation measures

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.

 

 

 

 

Polypharmacy Related Additional Prescribing Measures

2017-18

Desired change in indicator / measure

 

Cardiovascular

Oral anticoagulant: number of patients prescribed an antiplatelet also prescribed an oral anticoagulant but without gastroprotection as percentage of all patients prescribed an oral anticoagulant

 

Respiratory

Short Acting Beta-Agonist (SABA) Inhalers: number of patients prescribed more than 12 SABA inhalers in a year as a percentage of all patients prescribed SABAs

 

CNS - psychotropic

Antipsychotics: antipsychotic prescribing to patients aged ≥75 years as a percentage of all people aged ≥75 years

 

CNS - analgesic

Opioid analgesics: number of patients prescribed average daily dose of opioid equivalent to ≥ 120mg per day of morphine as a % of all patients prescribed step 2 and strong opioids††

↓↑

 

Opioid analgesics: number of patients prescribed strong opioids (including tramadol preparations) long term (>2 years) as a percentage of all patients prescribed strong opioids

 

Gabapentanoids: number of people prescribed more than the maximal recommended dose (>2 DDDs) per day of gabapentanoid as a percentage of all people prescribed a gabapentanoids (6 months) UPDATED

↓↑

 

CNS - adverse effects

Anticholinergics: number of patients aged ≥75 dispensed >10 items of strong or very strong anticholinergics (mARS 3&2) in 12 months as a percentage of all people aged ≥75 years

 

Antibiotics

Antibiotics: number of people > 4 antibiotics per annum per 1,000 LS

 

Antibiotics: number of adult women prescribed a 3-day course of acute UTI antibiotics as a percentage of all adult women prescribed acute UTI antibiotics

 
 

Antidiabetics

SMBG: number of patients prescribed blood glucose test strips who are not prescribed treatments for diabetes (insulins and/or antidiabetic drugs) or are only prescribed metformin as a percentage of all patients prescribed blood glucose test strips

 

SMBG: number of patients prescribed insulin not prescribed blood glucose test strips as a percentage of patients prescribed insulin

 

Musculoskeletal

NSAIDs: NSAID prescribing to patients aged  ≥65 years prescribed an ACE inhibitor/angiotensin receptor blocker and a diuretic as a percentage of all people aged  ≥65 years

 

NSAIDs: NSAID prescribing to patients aged ≥65 years prescribed an antiplatelet without gastroprotection as a percentage of all people aged  ≥65 years

 

NSAIDs: NSAID prescribing to patients aged ≥75 years without gastroprotection as a percentage of all people aged  ≥75 years

 

NSAIDs: NSAID prescription to patients prescribed an oral anticoagulant without gastroprotection as a percentage of all patients prescribed an oral anticoagulant

 

 

Clinical Outcomes - hospital admissions reduction measures

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.

Clinical Outcomes - undesirable increase in specific hospital admissions- balancing measures

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

Clinical Outcomes - reductions in all cause health care utilisation

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