Trends in prescriptions and costs of inhaled medications in chronic obstructive pulmonary disease: a 19-year population-based study from Canada

Figures & data

Table 1 Characteristics of patients in the study cohort. Number of patients (and percent of cohort) are reported unless otherwise indicated

Patient-related variables	Study cohort (N=176,338)
Female sex (%)	85,507 (48.5%)
Age (SD^a)	68.7 (12.5)
Year from COPD Diagnosis	6.1 (4.3)
Death	75,997 (43.1%)
Socioeconomic scale (%)
Quantile 1	46,924 (26.6%)
Quantile 2	37,549 (21.3%)
Quantile 3	32,610 (18.5%)
Quantile 4	29,695 (16.8%)
Quantile 5	25,416 (14.4%)
Unknown	4144 (2.35%)
Rural area	30,153 (17.1%)
Patient-year-related variables
COPD hospitalization	179,912 (15.5%)
COPD-related outpatient visits
No outpatient visit	566,648 (48.8%)
≥1 GP visit	470,329 (40.6%)
≥1 Specialist visit	121,798 (10.5%)
Charlson comorbidity score (SD)	1.2 (2.4)
History of asthma diagnosis	180,926 (15.6%)
Pulmonary function test (PFT)	132,047 (11.4%)

Note: ^aStandard deviation.

Abbreviation: COPD, chronic obstructive pulmonary disease.

Figure 1 Trends in the proportion of patients filling at least one prescription (left) and average dose-adjusted number of canisters (right*) for major COPD inhaled therapies, from 1997 to 2015.

Notes: *Numbers in brackets on the right panel legend give the average change between consecutive years. The baseline year for the trend is the first year of the medication’s presence in BC: 1997 for ICS, SABA, SAMA, LABA, and SAMA/SABA, 1999 for ICS/LABA, 2002 for LAMA, 2013 for LAMA/LABA (which is not presented in the figure due to the short duration).
Abbreviations: ICS, inhaled corticosteroids; LABA, long-acting beta-2 adrenoceptor agonists; LAMA, and long-acting muscarinic agents; SABA, short-acting beta-agonists; SAMA, short-acting muscarinic agents.

Figure 2 Trends in annual per-patient costs of COPD inhaled therapies from 1997 to 2015*.

Notes: *Numbers in brackets in the legend give the average change between consecutive years. The baseline year for the trend is the first year of the medication’s presence in BC: 1997 for ICS, SABA, SAMA, LABA, and SAMA/SABA, 1999 for ICS/LABA, 2002 for LAMA, 2013 for LAMA/LABA (which is not presented in the figure due to the short duration).
Abbreviations: ICS, inhaled corticosteroids; LABA, long-acting beta-2 adrenoceptor agonists; LAMA, and long-acting muscarinic agents; SABA, short-acting beta-agonists; SAMA, short-acting muscarinic agents.

Figure 3 Trends in the percent of users on combination therapies (left), and (right*) average medication possession ratio per patient-year from 1997 to 2015.

Notes: *Numbers in brackets in the legend of the right panel give the average change between consecutive years. The baseline year for the trend is the first year of the medication’s presence in BC: 1997 for ICS, SABA, SAMA, LABA, and SAMA/SABA, 1999 for ICS/LABA, 2002 for LAMA, 2013 for LAMA/LABA (which is not presented in the figure due to the short duration).
Abbreviations: ICS, inhaled corticosteroids; LABA, long-acting beta-2 adrenoceptor agonists; LAMA, and long-acting muscarinic agents; ICS/LABA/LAMA, triple therapy.

Table 2 Factors associated with the number of dispensed canisters of inhaled therapy in COPD patients

	ICS	LABA	LAMA	SAMA	SABA
Age (per 10 years)	8.26% (7.61, 8.90%)*	9.66% (8.85, 10.47%)*	13.17% (8.93, 17.58%)*	16.48% (14.93, 18.04%)*	−5.06% (−5.75, −4.38%)*
Sex (Female vs Male)	2.62% (1.16, 4.09%)*	1.05% (−0.79, 2.93%)	−7.63% (−14.91, 0.26%)	−1.11% (−4.07, 1.94%)	−7.62% (−9.25, −5.97%)*
Rural vs Urban	8.72% (6.62, 10.86%)*	2.42% (−0.15, 5.05%)	40.74% (19.55, 65.68%)*	26.92% (21.90, 32.15%)*	14.03% (11.43, 16.69%)*
Socioeconomic status^a
Quantile 1	Reference
Quantile 2	−2.26% (−4.28, −0.21%)*	1.61% (−1.12, 4.42%)	0.74% (−12.09, 15.45%)	−8.86% (−12.60, −4.96%)*	−9.31% (−11.50, −7.07%)*
Quantile 3	−4.17% (−6.20, −2.10%)*	1.93% (−0.90, 4.85%)	−0.96% (−12.34, 11.90%)	−11.88% (−15.82, −7.74%)*	−13.37% (−15.62, −11.07%)*
Quantile 4	−3.26% (−5.42, −1.06%)*	3.91% (0.98, 6.92%)*	11.08% (−5.80, 30.97%)	−12.63% (−16.72, −8.34%)*	−16.65% (−18.89, −14.35%)*
Quantile 5	−2.79% (−5.04, −0.49%)*	6.19% (3.11, 9.37%)*	7.52% (−5.53, 22.38%)	−19.36% (−23.35, −15.16%)*	−20.09% (−22.63, −17.47%)*
Unknown	0.16% (−4.50, 5.05%)	−4.40% (−10.51, 2.12%)	−19.09% (−33.70, −1.25%)*	0.72% (−7.28, 9.42%)	1.82% (−3.48, 7.41%)
Calendar year	−1.14% (−1.29, −0.99%)*	2.85% (2.66, 3.04%)*	4.09% (2.41, 5.79%)*	−8.48% (−8.76, −8.20%)*	−5.22% (−5.39, −5.06%)*
Year from COPD diagnosis	5.88% (5.71, 6.05%)*	6.38% (6.18, 6.58%)*	6.93% (6.37, 7.51%)*	9.00% (8.59, 9.42%)*	5.23% (5.01, 5.45%)*
Death	4.68% (3.21, 6.18%)*	−7.77% (−9.32, −6.20%)*	−1.04% (−12.71, 12.19%)	48.83% (45.09, 52.67%)*	14.97% (13.22, 16.75%)*
COPD hospitalization	37.94% (36.44, 39.47%)*	24.04% (22.38, 25.73%)*	25.85% (16.77, 35.63%)*	98.80% (94.07, 103.64%)*	52.77% (50.83, 54.73%)*
COPD-related outpatient visits
No outpatient visit	Reference
≥1 GP visit	84.63% (82.39, 86.89%)*	103.28% (100.00, 106.62%)*	219.58% (191.32, 250.59%)*	131.10% (125.52, 136.82%)*	100.04% (97.26, 102.85%)*
≥1 Specialist visit	127.54% (124.13, 131.00%)*	206.95% (201.02, 212.99%)*	606.43% (521.80, 702.59%)*	169.62% (161.40, 178.11%)*	129.02% (125.02, 133.09%)*
Charlson comorbidity score	−1.80% (−2.03, −1.56%)*	−1.71% (−2.01, −1.41%)*	−2.72% (−4.02, −1.39%)*	−2.18% (−2.66, −1.70%)*	−2.04% (−2.31, −1.77%)*
History of asthma diagnosis	93.06% (90.92, 95.22%)*	67.40% (65.00, 69.84%)*	−0.19% (−6.54, 6.59%)	42.04% (38.37, 45.81%)*	93.82% (91.15, 96.54%)*
Pulmonary function test	17.14% (15.85, 18.44%)*	32.58% (30.74, 34.45%)*	51.16% (40.39, 62.76%)*	−1.45% (−3.81, 0.97%)	1.29% (−0.07, 2.68%)

Notes: *Significant at 0.05 level. ^aAccording to neighborhood income levels individuals in BC are categorized into five categories based on the total income quantile.

Abbreviations: COPD, chronic obstructive pulmonary disease; GP, general practitioner; ICS, inhaled corticosteroids; LABA, long-acting beta-agonists; LAMA, and long-acting muscarinic agents; SABA, short-acting beta-agonists; SAMA, short-acting muscarinic agents.