RESUMEN
Introduction: Conservative estimates suggest that the cost of poor medication adherence (MA) to healthcare systems in the UK is close to 800Mn annually, however figures may be as high as 920Mn to 224Bn across larger parts of Europe and the US.(1) This may be attributed to the relationship between poor MA and an increased risk of hospital admission.(2) Often, cases are preventable and hence present an opportunity for avoidable costs if appropriately identified and managed, such as in the case of early readmissions (admissions occurring within 30 days of discharge). However, despite the association between MA and admissions, to date no predictive model has been developed that integrates a holistic Patient-Reported Outcome Measure (PROM) of MA. This study evaluated one such PROM, known as SPUR, as a predictor of general admission and early readmission in patients living with Type 2 Diabetes (T2D). Aim(s): This study sought to develop a predictive model of early readmission and general admission risk using the SPUR tool as a PROM of MA in patients living with T2D. Method(s): Using an observational study design, 6-month retrospective and prospective patient monitoring were conducted to assess the number of admissions and early readmissions during the observational period. Outcomes were reported as binary and count variables. Patients were previously recruited from a large London NHS Trust as part of a cross-sectional study to validate SPUR. Covariates of interest included: age, ethnicity, gender, education level, income, the number of medicines and medical conditions, and Covid-19 diagnoses. A Poisson or negative binomial model was employed for count outcomes, with the exponentiated coefficient indicating incident ratios (IR) [95% CI]. For binary outcomes (Coefficient, [95% CI]), a logistic regression model was developed. Result(s): Data were available for 200 patients. The modal age range was 70-79 years (n=74/200, 37.0%). Most participants were GCSE educated (42.5%), white (76.0%), and over a third female (36.0%) identified as female. For general admission risk as a count variable, a higher SPUR score (increased adherence) was significantly associated with a lower number of admissions (IR = 0.98, [0.96, 1.00]). Other factors associated with an increased risk of admission included: age >=80 years (IR = 5.18, [1.01, 26.55]), GCSE education (IR = 2.11, [1.15 - 3.87]), number of medical conditions (IR = 1.07, [1.01, 1.13]), and a positive Covid- 19 diagnosis during follow-up (IR = 1.83, [1.11, 3.02]). SPUR remained significant when modelled as a binary variable (-0.048, [-0.094, -0.003]). For early readmission, only the SPUR score was significantly predictive of the outcome as a binary variable (-0.051, [-0.094, -0.007]), indicating that those with a higher SPUR score were at less risk of an early readmission. Conclusion(s): The study successfully developed a predictive model for both general admission and early readmissions in patients living with T2D using the SPUR tool and several covariates of clinical relevance. However, a small sample size is noted as a limitation. Future work may look to integrate SPUR as a holistic PROM of MA to support the development of tailored interventions to reduce patients' risk of admission.
RESUMEN
Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a respiratory condition characterised by a progressive and irreversible decline in lung function. COPD prevalence increased by 44.2% between 1990 and 2015, resulting in 3.2 million deaths globally in 2015.(1) Inhalers are an essential treatment for people living with COPD. However, poor adherence to inhaled medicines is associated with worsening symptom severity, increased hospitalisation, comorbidity, and mortality.(2) Patient Reported Outcome Measures (PROMs) have been designed to examine the factors that contribute to poor medication adherence (MA). To date, none provide a holistic assessment that could be used to design tailored MA interventions. This study sought to address this by evaluating a novel PROM that holistically assesses four key factors of MA referred to as Social, Psychological, Usage, and Rationale, in short, SPUR. Aim(s): To explore the validity of the SPUR model as a holistic PROM of MA in patients living with COPD Methods: This cross-sectional study surveyed adults living with COPD from a large London NHS Trust between January and December 2021. Participants were eligible if they had >=1 inhaler prescribed for a minimum of 6 months prior to the study and were able to read and write in English. Participants who were too clinically unwell to independently complete the survey were excluded, which often included those with a Covid-19 diagnoses. Convenience sampling was used to recruit participants from in-patient wards and the acute admissions unit prior to administration of face-to-face surveys. Survey questions related to socio-clinical data, the SPUR tool, and a previously validated PROM known as the Inhaler Adherence Scale (IAS) that was included as a comparator. The Medication Possession Ratio (MPR), a measure of a patient's pill count in a given time period, was used as an objective comparator of MA. MPR, IAS, and SPUR scores were compared using Spearman's rank correlation coefficient (p). Symptom severity was examined using the COPD Assessment Test (CAT), with a Chi-square analysis (chi2) conducted to explore the relationship between the CAT and SPUR. Result(s): From 123 patients approached for this study, 100 participated providing a response rate of 81.3%. The modal age range was 70-79 years. Participants were predominantly white (90%), educated to GCSE level (51%), and identified as female (52%). Over two thirds (67%) were ex-smokers. SPUR was significantly (p<0.01) and positively correlated with IAS (p=0.65) and MPR (p=0.30), demonstrating that SPUR is a valid measure of MA. Chi-Square analysis identified a significant (p<0.01) relationship between CAT and SPUR scores (chi2=8.570);hence SPUR could reliably identify patients with poorer adherence, which was associated with worsening symptom severity. Conclusion(s): A study strength includes the implementation of an objective measure (MPR) and PROM (IAS) as part of validating SPUR. However, the results should be treated cautiously given the small sample size, which was limited due to Covid-19. This study provides early evidence of SPUR as a reliable holistic measure of MA with significant associations to COPD symptom severity, which could be applied in clinical practice to prospectively address patient outcomes linked to poor MA.