Diffusion of new medication across different income groups under a universal health insurance program: an example involving newly enlisted nonsteroidal anti-inflammatory drugs for elderly osteoarthritis patients.
OBJECTIVE
The aim of this research was to determine whether socioeconomic status, as measured by income level, impacts on the diffusion to patients of newly reimbursed nonsteroidal anti-inflammatory drugs (NSAIDs) under the National Health Insurance program in Taiwan.


METHODS
We used income tax records to identify the income levels of 324 male and 551 female randomly sampled osteoarthritis patients aged over 60 years in 2000. The study period was 2 years (t (1) = April 2001-March 2002 and t (2) = April 2002-March 2003). Generalized estimating equation models were used to analyze the impact of income level on being prescribed one of the newly reimbursed NSAIDs.


RESULTS
The impact of income level on being treated with the new drug was positive and significant for females (OR = 2.11, p < 0.01) but not for males. The interaction term between income groups and the time trend was insignificant. Other factors associated with being treated with the new drug include age, habit of health-care utilization, and residential characteristics.


CONCLUSIONS
Diffusion of new drugs still depends on income level despite the presence of a universal national health insurance system in Taiwan.
Wang
Pen-Jen
PJ
Bureau of National Health Insurance, Department of Health, Taipei, Taiwan.
Chou
Yiing-Jenq
YJ
Lee
Cheng-Hua
CH
Pu
Christy
C
D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D004059:Diffusion of Innovation; D005260:Female; D006297:Health Services Accessibility / Q000191:economics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data*; D016017:Odds Ratio; D010003:Osteoarthritis / Q000188:drug therapy*; D012737:Sex Factors; D012923:Social Class; D013624:Taiwan
D000894:Anti-Inflammatory Agents, Non-Steroidal