Dataset Information

Impact on glycated haemoglobin of a biological response-based measure of medication adherence.

ABSTRACT:

Aims

The aim of this study was to examine the relationship between a specific glycated haemoglobin (HbA1c) measurement and a pharmaceutical dispensings-based measure of adherence calculated over the 90 days before each HbA1c measure among patients who have newly initiated metformin therapy.

Methods

We identified 3109 people with type 2 diabetes who initiated metformin as their first-ever antihyperglycaemic drug, analysing all 9918 HbA1c measurements that were taken over the next 2 years. We used an adaptation of the 'proportion of days covered' method for assessing medication adherence that corresponded to an ?90-day interval preceding an HbA1c measurement, terming the adaptation the 'biological response-based proportion of days covered' (BRB-PDC). To account for multiple observations per patient, we analysed the association between HbA1c and BRB-PDC within the generalized estimating equation framework. Analyses were stratified by HbA1c level before metformin initiation using a threshold of 8% (64 mmol/mol).

Results

After multivariable adjustment using 0% adherence as the reference category, BRB-PDC in the range 50-79% was associated with HbA1c values lower by -0.113 [95% confidence interval (CI) -0.202, -0.025] among patients with pre-metformin HbA1c <8%, and by -0.247 (95% CI -0.390, -0.104) among those with HbA1c ?8% at metformin initiation. Full adherence (?80%) was associated with HbA1c values lower by -0.175% (95% CI -0.257, -0.093) and by -0.453% (95% CI -0.586, -0.320).

Conclusions

Using this novel short-interval approach that more closely associates adherence with the expected biological response, the association between better adherence and HbA1c levels was considerably stronger than has been previously reported; however, the strength of the impact was dependent upon the HbA1c level before initiating metformin.

SUBMITTER: Nichols GA

PROVIDER: S-EPMC5033018 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature

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Impact on glycated haemoglobin of a biological response-based measure of medication adherence.

Nichols G A GA Rosales A G AG Kimes T M TM Tunceli K K Kurtyka K K Mavros P P Steiner J F JF

Diabetes, obesity & metabolism 20150520 9

<h4>Aims</h4>The aim of this study was to examine the relationship between a specific glycated haemoglobin (HbA1c) measurement and a pharmaceutical dispensings-based measure of adherence calculated over the 90 days before each HbA1c measure among patients who have newly initiated metformin therapy.<h4>Methods</h4>We identified 3109 people with type 2 diabetes who initiated metformin as their first-ever antihyperglycaemic drug, analysing all 9918 HbA1c measurements that were taken over the next 2 ...[more]

PMID: 25880136

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Project description:PurposeTo assess possible changes in medication adherence to prostaglandin analog (PGA) regimens among patients with open-angle glaucoma (OAG) after the initial introduction of generic PGAs.DesignLongitudinal cohort analysis.ParticipantsPatients older than 40 years with OAG continuously enrolled in a nationwide managed-care network during 2009-2012 who used PGAs.MethodsMean adherence rates were calculated for topical PGA use during the 18 months before the introduction of generic latanoprost (September 2009-February 2011) and the 18 months after generic latanoprost became available (July 2011-December 2012). The rates were compared between persons who continued to use brand-name PGAs once generic latanoprost became available and others who switched to generic latanoprost. Multivariable logistic regression identified variables associated with an improvement or worsening of adherence of ≥25%.Main outcome measuresMean adherence rates and odds of 25% or more improved or worsened adherence (with 95% confidence intervals [CIs]).ResultsA total of 8427 patients met the study eligibility criteria. Compared with persons switching to generic latanoprost, patients who continued taking brand name PGAs were 28% less likely to have improved adherence (odds ratio [OR], 0.72; 95% CI, 0.55-0.94) and 39% more likely to have reduced adherence (OR, 1.39; 1.04-1.86) of ≥25%. Improved adherence after the generic drug's introduction was also associated with higher monthly medication copay in the pregeneric period (P = 0.02), lower copay after introduction of the generic drug (P < 0.0001), and black race (OR, 1.25; 95% CI, 1.04-1.50). Six-hundred twelve patients (7.3%) discontinued all antiglaucoma interventions when generic latanoprost became available.ConclusionsGiven that cost can significantly deter adherence, switching patients to generic medications may help improve patients' drug-regimen adherence. A considerable number of patients discontinued glaucoma drug use altogether when generic latanoprost became available. Ophthalmologists should work with insurers and pharmacists to prevent such discontinuation of use as generic forms of other PGA agents become available.

Project description:OBJECTIVE:To determine the economic impact of medication non-adherence across multiple disease groups. DESIGN:Systematic review. EVIDENCE REVIEW:A comprehensive literature search was conducted in PubMed and Scopus in September 2017. Studies quantifying the cost of medication non-adherence in relation to economic impact were included. Relevant information was extracted and quality assessed using the Drummond checklist. RESULTS:Seventy-nine individual studies assessing the cost of medication non-adherence across 14 disease groups were included. Wide-scoping cost variations were reported, with lower levels of adherence generally associated with higher total costs. The annual adjusted disease-specific economic cost of non-adherence per person ranged from $949 to $44?190 (in 2015 US$). Costs attributed to 'all causes' non-adherence ranged from $5271 to $52?341. Medication possession ratio was the metric most used to calculate patient adherence, with varying cut-off points defining non-adherence. The main indicators used to measure the cost of non-adherence were total cost or total healthcare cost (83% of studies), pharmacy costs (70%), inpatient costs (46%), outpatient costs (50%), emergency department visit costs (27%), medical costs (29%) and hospitalisation costs (18%). Drummond quality assessment yielded 10 studies of high quality with all studies performing partial economic evaluations to varying extents. CONCLUSION:Medication non-adherence places a significant cost burden on healthcare systems. Current research assessing the economic impact of medication non-adherence is limited and of varying quality, failing to provide adaptable data to influence health policy. The correlation between increased non-adherence and higher disease prevalence should be used to inform policymakers to help circumvent avoidable costs to the healthcare system. Differences in methods make the comparison among studies challenging and an accurate estimation of true magnitude of the cost impossible. Standardisation of the metric measures used to estimate medication non-adherence and development of a streamlined approach to quantify costs is required. PROSPERO REGISTRATION NUMBER:CRD42015027338.

Dataset Information

Impact on glycated haemoglobin of a biological response-based measure of medication adherence.

Aims

Methods

Results

Conclusions

Publications

Impact on glycated haemoglobin of a biological response-based measure of medication adherence.

Similar Datasets

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