This measure assesses the percentage of patients diagnosed with bipolar disorder and treated with lithium who have evidence of a lithium serum medication level within 12 weeks of beginning treatment.
Clinical Rationale:
Side Effects of Lithium
Up to 75% of patients on lithium experience some side effects, but most are minor (polyuria; polydipsia, weight gain, cognitive problems, sedation or lethargy) and can be reduced or eliminated by dose adjustment or dosage schedule (1)
Tremor affects up to 65% of patients treated with lithium and a severe tremor may be a sign of toxicity. Nausea and diarrhea or blurred vision may also be side effects of toxicity (1,2)
Lithium Levels
Target lithium levels are generally 0.8-1.1 mmol/L (3)
Serum concentrations of 0.5 to 1.2 meq/L may be therapeutic according to individual patient response and side effects (1)
Patients can experience toxic effects with levels above 1.5 meq/L such as marked tremor, nausea and diarrhea, or blurred vision; levels above 2.0 meq/L are have been associated with life-threatening side effects, such as neurotoxicity, delirium and encephalopathy (1,2)
Monitoring of Serum Lithium Levels
Lithium level monitoring is required due to the medication’s narrow therapeutic index (1,2)
Check lithium level after initial dosage and after each dosage increase (1)
It is recommended to obtain serum levels approximately 5 days after a dosage adjustment as this is when the steady state is reached (1,3)
Long-term monitoring recommendations are to check every 3-6 months in patients with stable lithium levels and whenever the clinical status changes (1,3)
Denominator Population:
Patients diagnosed and treated for bipolar disorder with a lithium agent
Data Sources:
Administrative data
Medical Record
Numerator Population:
Patients with a serum medication level within 12 weeks of beginning treatment with lithium
Data Source:
Medical Record
Initial Case-finding Guidance:
Patients with a diagnosis involving bipolar disorder
ICD9CM or DSM IV TR: 296.0x; 296.1x; 296.4x; 296.5x; 296.6x; 296.7; 296.80-82; 296.89; or 301.13
References:
Practice Guideline for the Treatment of Patients with Bipolar Disorder (2002 Revision); American Psychiatric Association; Am J Psychiatry 159:4, April 2002 Supplement
Freeman M, Freeman S, Lithium: Clinical Considerations in Internal Medicine, The American Journal of Medicine (2006) 119, 478-481
Yatham LN, Kennedy, SH, et al.; Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines for the managements of patients with bipolar disorder: consensus and controversies, Bipolar Disorders 2005: 7(Suppl. 3): 5-69
