Abstract: Objective To explore the characteristics and dosing patterns of elderly patients who take Lianhua Qingwen capsules, and to provide data for drug monitoring or epidemiological studies on elderly patients. Methods The medical data on elderly patients who used Lianhua Qingwen capsules between September 30, 2004 and December 31, 2015 was retrieved from the information systems of 18 hospitals across China before being standardized and modeled with the Apriori algorithm. Clementine 18.0 software was used for association rule analysis. Results The age of the 2 247 patients mostly ranged from 65 to 70 (44.19%). There were slightly more males than females. The first diagnosis of these patients upon admission was mainly pulmonary infections (10.01%). These elders became more vulnerable around October 8 every year(7.43%). Oral medication was dominating (91.86%), and a single dose was equal or lesser than 3 g(70.05%). The duration of treatment was mostly between 15 and 28 d (41.88%). The commonly used western drugs included acetylsalicylic acid (3.65%), amiloride (2.47%), and levofloxacin (1.92%). And traditional Chinese medicines that were often used in combination with western drugs were danhong injection (3.68%) and Tanreqing injection (2.53%). Conclusion Elderly patients who use Lianhua Qingwen capsules are likely to have developed pulmonary infections, and the comorbidities are mostly cardiovascular and cerebrovascular diseases. Single-dose drug specifications need to be standardized while combined medication should comply with the guidelines.

Key words: Lianhua Qingwen capsules, elderly patients, lung infection, real world, modes of medication