“Increasing the effectiveness of adherence interventions may have a far greater impact on the health of the population than any improvement in specific medical treatments.”

— World Health Organisation

Taking medicine as prescribed is not easy

Life happens, and there are many both intentional and unintentional reasons for not taking your medicine, here are some of them.

  • Remembering if you took your medication

  • Fear of side-effects

  • Changing habits

  • Being unsure about getting the right treatment

  • Simply forgetting

  • Life gets in the way

Adherence statistics

Average cost savings with 1% improved adherence in clinical trials (US dollar)

Around 40% of participants enrolled in clinical studies do not take their medicine as prescribed after the first 150 days. This leads to longer more costly trials and an increased number of participants required to keep statistical power. As shown in the table, a one per cent improvement in adherence can result in a saving of 423.000$ in costs in all trial phases. Being informed about the participant's adherence level enables a faster dose selection. The dosing regimen selection is a leading reason for delays in the regulatory approval of a drug.

References: M.Alsumidaie (2017) Non-Adherence: A Direct Influence on Clinical Trial Duration and Cost

Clinical trials

Today’s cost of non-adherence

Poor adherence leads to fewer days of treatment, unnecessary treatment switches and large financial losses. On a global scale, non-adherence is estimated to reach an avoidable cost of 171 billion US dollars per year for the healthcare system. 

References: T.Aitken et al. (2012) Advancing the Responsible Use of Medicines: Applying Levers for Change

Medical treatment

“
Without any objective measurement of drug compliance, physicians have become used to opting almost always...for enhancing doses or prescribing new drug combinations... However, there is usually no rational basis for this decision.

As Burnier et al.

33%-69% of medication-related hospital admission are caused by non-adherence.

Patient health

Not taking medication as prescribed leads to poor health outcomes. Only in the United States, non-adherence is associated with 125 000 deaths, 10% of hospitalisations and $100 billion in healthcare services annually. Globally,
non-adherence is estimated to cause 33% to 69% of medication-related hospital admission.

References: V.Kini and P.M Ho (2018) Interventions to Improve Medication Adherence: A review, L.Osterberg and T.Blaschke (2005) Adherence to Medication

 Among patients with chronic illnesses, 50% do not take medications as prescribed.

Chronic diseases

Treatment of chronic illnesses commonly includes long-term medication. Although these medications are effective, their full benefits are often not realised because approximately 50% of patients do not take their medicine as prescribed. This leads to increased illness and death and is estimated to result in costs of $100 billion per year.

References: M.T Brown and J.K Bussell (2011) Medication Adherence: WHO Cares?  

Failure to confirm efficacy,
example: HIV therapy

When self-reporting, 90% of patients reported that they adhere to treatment. When pill counting it was revealed that only 86% of the patients were adhering to their treatment. After taking plasma samples through blood tests the percentage of patients that were adherent dropped to 30%. A far less percentage than what was reported by the patients themselves originally.

Reference: M.Burnier (2019) Is there a threshold for medication adherence? Lessons learnt from electronic monitoring of drug Adherence

Adherence based on self-reports

Adherence based on returned products counts

Adherence-based plasma samples through blood tests