A rapid desktop theophylline assay. Evaluation of use in clinical management.
OBJECTIVE
To assess the practicality and precision of a simple desktop theophylline assay (Biotrack 516TM) in comparison to a standard laboratory assay system (Abbott TDxTM).


METHODS
A prospective blinded paired sample study.


METHODS
The respiratory ward and outpatient clinics, the pulmonary function and biochemistry laboratories of a university teaching hospital.


METHODS
Sixty patients with asthma or COPD attending the respiratory service.


RESULTS
Paired specimens for theophylline assay were collected simultaneously for analysis. There was a highly significant (p < 0.001) correlation between the two assay systems for both the total range studied (1.2-39.1 micrograms/mL; r = 0.98), and the clinically important range of 5-15 micrograms/mL (r = 0.95). The limits of agreement for the data by the Bland and Altman method indicated a +/-2 micrograms/mL limit for the 5-15 micrograms/mL range and a +/-2.7 micrograms/mL limit for the total range studied.


CONCLUSIONS
The Biotrack 516 is an easy-to-use system, which provides rapid and reasonably precise measurements of serum theophylline levels. The device should be of particular value in smaller centers without an on-site laboratory assay system.
Kiely
J L
JL
Department of Respiratory Medicine, St. Vincent's Hospital, Dublin, Ireland.
Lawless
G
G
Cunningham
S
S
McNicholas
W T
WT
D005069:Evaluation Studies as Topic; D006801:Humans; D007118:Immunoassay / Q000191:economics / Q000379:methods*; D011446:Prospective Studies; D016037:Single-Blind Method; D013806:Theophylline / Q000097:blood*
D013806:Theophylline