Monitoring adherence to drug treatment by using change in cholesterol concentration: Secondary analysis of trial data

Katy J L Bell, Adrienne Kirby, Andrew Hayen, Les Irwig, Paul Glasziou

Research output: Contribution to journalArticleResearchpeer-review

13 Citations (Scopus)
83 Downloads (Pure)

Abstract

Objective: To estimate the accuracy of monitoring cholesterol concentration for detecting non-adherence to lipid lowering treatment. Design: Secondary analysis of data on cholesterol concentration in the LIPID (long term intervention with pravastatin in ischaemic disease) study by using three measures of non-adherence: discontinuation of treatment, allocation to placebo arm, less than 80% of pills taken. Setting: Randomised placebo controlled trial in Australia and New Zealand. Participants: 9014 patients with previous coronary heart disease. Interventions: Pravastatin 40 mg or placebo daily. Main outcome measures: Sensitivity, specificity, area under the receiver operating characteristics (ROC) curve, post-test probability. Results: Monitoring of cholesterol concentration had modest ability for detecting complete non-adherence. One year after the start of treatment, half (1957/3937) of the non-adherent patients and 6% (253/3944) of adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was reasonable (area under the curve 0.89). Cholesterol monitoring, however, had weak ability for detecting partial non-adherence. One year after the start of treatment,16%(34/213) of partially adherent and 4% (155/3585) of fully adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was poor (area under the curve 0.65). For typical pre-test probabilities of non-adherence ranging from low (25%) to high (75%), the post-test probabilities indicate continuing uncertainty after lipid testing. A patient with no change in low density lipoprotein cholesterol concentration has a post-test probability of being completely non-adherent of between 67% and 95% and a post-test probability of being partially non-adherent of between 48% and 89%. A patient with a decrease in concentration of 1.0 mmol/L has a post-test probability of being completely non-adherent of between 7% and 40% and a post-test probability of being partially non-adherent of between 21% and 71%. Conclusions: Monitoring concentration of low density lipoprotein (or total) cholesterol has modest ability to detect complete non-adherence or non-persistence with pravastatin treatment and weak ability to detect partial non-adherence. Results of monitoring should be considered as no more than an adjunct to careful discussion with patients about adherence.

Original languageEnglish
Article numberd12
Pages (from-to)269
Number of pages1
JournalBritish Medical Journal
Volume342
Issue number7791
DOIs
Publication statusPublished - 29 Jan 2011

Fingerprint

Cholesterol
Aptitude
Pravastatin
Pharmaceutical Preparations
LDL Cholesterol
Placebos
Therapeutics
Area Under Curve
Lipids
Patient Compliance
New Zealand
LDL Lipoproteins
ROC Curve
Uncertainty
Coronary Disease
Randomized Controlled Trials
Outcome Assessment (Health Care)
Sensitivity and Specificity

Cite this

Bell, Katy J L ; Kirby, Adrienne ; Hayen, Andrew ; Irwig, Les ; Glasziou, Paul. / Monitoring adherence to drug treatment by using change in cholesterol concentration : Secondary analysis of trial data. In: British Medical Journal. 2011 ; Vol. 342, No. 7791. pp. 269.
@article{9b9e7cdd725443628ba9d8ede21055aa,
title = "Monitoring adherence to drug treatment by using change in cholesterol concentration: Secondary analysis of trial data",
abstract = "Objective: To estimate the accuracy of monitoring cholesterol concentration for detecting non-adherence to lipid lowering treatment. Design: Secondary analysis of data on cholesterol concentration in the LIPID (long term intervention with pravastatin in ischaemic disease) study by using three measures of non-adherence: discontinuation of treatment, allocation to placebo arm, less than 80{\%} of pills taken. Setting: Randomised placebo controlled trial in Australia and New Zealand. Participants: 9014 patients with previous coronary heart disease. Interventions: Pravastatin 40 mg or placebo daily. Main outcome measures: Sensitivity, specificity, area under the receiver operating characteristics (ROC) curve, post-test probability. Results: Monitoring of cholesterol concentration had modest ability for detecting complete non-adherence. One year after the start of treatment, half (1957/3937) of the non-adherent patients and 6{\%} (253/3944) of adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was reasonable (area under the curve 0.89). Cholesterol monitoring, however, had weak ability for detecting partial non-adherence. One year after the start of treatment,16{\%}(34/213) of partially adherent and 4{\%} (155/3585) of fully adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was poor (area under the curve 0.65). For typical pre-test probabilities of non-adherence ranging from low (25{\%}) to high (75{\%}), the post-test probabilities indicate continuing uncertainty after lipid testing. A patient with no change in low density lipoprotein cholesterol concentration has a post-test probability of being completely non-adherent of between 67{\%} and 95{\%} and a post-test probability of being partially non-adherent of between 48{\%} and 89{\%}. A patient with a decrease in concentration of 1.0 mmol/L has a post-test probability of being completely non-adherent of between 7{\%} and 40{\%} and a post-test probability of being partially non-adherent of between 21{\%} and 71{\%}. Conclusions: Monitoring concentration of low density lipoprotein (or total) cholesterol has modest ability to detect complete non-adherence or non-persistence with pravastatin treatment and weak ability to detect partial non-adherence. Results of monitoring should be considered as no more than an adjunct to careful discussion with patients about adherence.",
author = "Bell, {Katy J L} and Adrienne Kirby and Andrew Hayen and Les Irwig and Paul Glasziou",
year = "2011",
month = "1",
day = "29",
doi = "10.1136/bmj.d12",
language = "English",
volume = "342",
pages = "269",
journal = "BMJ (Clinical research ed.)",
issn = "0959-535X",
publisher = "BMJ Publishing Group",
number = "7791",

}

Monitoring adherence to drug treatment by using change in cholesterol concentration : Secondary analysis of trial data. / Bell, Katy J L; Kirby, Adrienne; Hayen, Andrew; Irwig, Les; Glasziou, Paul.

In: British Medical Journal, Vol. 342, No. 7791, d12, 29.01.2011, p. 269.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Monitoring adherence to drug treatment by using change in cholesterol concentration

T2 - Secondary analysis of trial data

AU - Bell, Katy J L

AU - Kirby, Adrienne

AU - Hayen, Andrew

AU - Irwig, Les

AU - Glasziou, Paul

PY - 2011/1/29

Y1 - 2011/1/29

N2 - Objective: To estimate the accuracy of monitoring cholesterol concentration for detecting non-adherence to lipid lowering treatment. Design: Secondary analysis of data on cholesterol concentration in the LIPID (long term intervention with pravastatin in ischaemic disease) study by using three measures of non-adherence: discontinuation of treatment, allocation to placebo arm, less than 80% of pills taken. Setting: Randomised placebo controlled trial in Australia and New Zealand. Participants: 9014 patients with previous coronary heart disease. Interventions: Pravastatin 40 mg or placebo daily. Main outcome measures: Sensitivity, specificity, area under the receiver operating characteristics (ROC) curve, post-test probability. Results: Monitoring of cholesterol concentration had modest ability for detecting complete non-adherence. One year after the start of treatment, half (1957/3937) of the non-adherent patients and 6% (253/3944) of adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was reasonable (area under the curve 0.89). Cholesterol monitoring, however, had weak ability for detecting partial non-adherence. One year after the start of treatment,16%(34/213) of partially adherent and 4% (155/3585) of fully adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was poor (area under the curve 0.65). For typical pre-test probabilities of non-adherence ranging from low (25%) to high (75%), the post-test probabilities indicate continuing uncertainty after lipid testing. A patient with no change in low density lipoprotein cholesterol concentration has a post-test probability of being completely non-adherent of between 67% and 95% and a post-test probability of being partially non-adherent of between 48% and 89%. A patient with a decrease in concentration of 1.0 mmol/L has a post-test probability of being completely non-adherent of between 7% and 40% and a post-test probability of being partially non-adherent of between 21% and 71%. Conclusions: Monitoring concentration of low density lipoprotein (or total) cholesterol has modest ability to detect complete non-adherence or non-persistence with pravastatin treatment and weak ability to detect partial non-adherence. Results of monitoring should be considered as no more than an adjunct to careful discussion with patients about adherence.

AB - Objective: To estimate the accuracy of monitoring cholesterol concentration for detecting non-adherence to lipid lowering treatment. Design: Secondary analysis of data on cholesterol concentration in the LIPID (long term intervention with pravastatin in ischaemic disease) study by using three measures of non-adherence: discontinuation of treatment, allocation to placebo arm, less than 80% of pills taken. Setting: Randomised placebo controlled trial in Australia and New Zealand. Participants: 9014 patients with previous coronary heart disease. Interventions: Pravastatin 40 mg or placebo daily. Main outcome measures: Sensitivity, specificity, area under the receiver operating characteristics (ROC) curve, post-test probability. Results: Monitoring of cholesterol concentration had modest ability for detecting complete non-adherence. One year after the start of treatment, half (1957/3937) of the non-adherent patients and 6% (253/3944) of adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was reasonable (area under the curve 0.89). Cholesterol monitoring, however, had weak ability for detecting partial non-adherence. One year after the start of treatment,16%(34/213) of partially adherent and 4% (155/3585) of fully adherent patients had a rise in concentration of low density lipoprotein cholesterol. Accuracy was poor (area under the curve 0.65). For typical pre-test probabilities of non-adherence ranging from low (25%) to high (75%), the post-test probabilities indicate continuing uncertainty after lipid testing. A patient with no change in low density lipoprotein cholesterol concentration has a post-test probability of being completely non-adherent of between 67% and 95% and a post-test probability of being partially non-adherent of between 48% and 89%. A patient with a decrease in concentration of 1.0 mmol/L has a post-test probability of being completely non-adherent of between 7% and 40% and a post-test probability of being partially non-adherent of between 21% and 71%. Conclusions: Monitoring concentration of low density lipoprotein (or total) cholesterol has modest ability to detect complete non-adherence or non-persistence with pravastatin treatment and weak ability to detect partial non-adherence. Results of monitoring should be considered as no more than an adjunct to careful discussion with patients about adherence.

UR - http://www.scopus.com/inward/record.url?scp=79251568625&partnerID=8YFLogxK

U2 - 10.1136/bmj.d12

DO - 10.1136/bmj.d12

M3 - Article

VL - 342

SP - 269

JO - BMJ (Clinical research ed.)

JF - BMJ (Clinical research ed.)

SN - 0959-535X

IS - 7791

M1 - d12

ER -