Use of antibiotics and asthma medication for acute lower respiratory tract infections in people with and without asthma: retrospective cohort study

Table 2 Episode and measures of practice variance in medication prescribed within 3 days of ALRTI^a diagnosis, stratified by asthma^b status

	Patients with asthma	Patients without asthma
ALRTI episodes, n = 127,976 (n, %)
No treatment	3374 (16.1)	20,293 (19.0)
Antibiotics only^c	8985 (42.8)	70,944 (66.3)
^d Asthma medication only	508 (2.4)	1803 (1.7)
Oral steroid^e	298 (1.4)	808 (0.8)
Antibiotics^c and asthma medication^d	8123 (38.7)	13,946 (13.0)
Antibiotics^c and oral steroids^e	5341 (25.4)	6318 (5.9)
Practice variance, n = 513 (95% mid-range OR, 95% CI) ^f
No treatment	3.09 (2.41, 4.23)	2.04 (1.81, 2.36)
Antibiotics only^c	1.63 (1.46, 1.88)	1.89 (1.72, 2.13)
Asthma medication only^d	7.46 (4.00, 18.46)	17.18 (10.08, 33.1)
Oral steroid^e	17.76 (6.55, 81.91)	93.92 (33.15, 362.72)
Antibiotics^c and asthma medication^d	1.62 (1.45, 1.87)	2.46 (2.14, 2.91)
Antibiotics^c and oral steroids^e	2.94 (2.37, 3.84)	5.81 (4.39, 8.11)

IQR Interquartile range
^a Acute lower respiratory tract infection
^b Defined as ever diagnosed and asthma medication prescribed in the 12 months prior to ALRTI
^c Antibiotics limited to oral formulations and includes amoxicillin, doxycycline, clarithromycin, co-amoxiclav, azithromycin, erythromycin, tetracycline, cefalexin, cefradine
^d Among patients without asthma, asthma medication refers to any asthma medication, including oral corticosteroids. Among patients with asthma, asthma medication refers to an increase in the dose of current treatment and/or additional asthma medication (including oral corticosteroids) prescribed compared to the prior month
^e Oral steroids refer to oral corticosteroids
^f Practice variance was calculated from the variance of the random effect (σ2) and is given by e2 × 1.96 × σ and represents the odds ratio comparing a practice at the 2.5th percentile of the distribution of practices to one at the 97.5th percentile for the treatment outcome of interest. For example, amongst patients without asthma, practices who most frequently prescribed no treatment were 2.14 times more likely to prescribe no treatment compared to practices who prescribed no treatment the least

ISSN: 1465-993X