Low rates of participation and completion of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease in primary health care

Background: Only 6% of patients with chronic obstructive pulmonary disease (COPD) participate in pulmonary rehabilitation programs (PR) and only 50% of those who participate, complete these programs. Aim: To determine rates of PR program participation and completion among patients with COPD in Chile. Material and Methods: Analysis of a database available at the Ministry of Health, which included data of 277491 patients with COPD (55% females) and their participation in PR programs, between 2014 and 2016. Results: Forty percent of patients were over 75 years of age. Participation rates in PR programs ranged from 2.4 to 2.9%. Rates of completion ranged from 26 to 36%. Conclusions: There is a low rate of participation in PR programs among patients with COPD. Approximately one third of participants complete these programs. (Rev Med Chile 2018; 146: 1304-1308)

C hronic Obstructive Pulmonary Disease (COPD) is a chronic pulmonary condition that affects the quality of life.It is characterized by airflow obstruction, inflammation and emphysema 1 .COPD is the third cause of death in the world 2 .Its prevalence is 4-10% 3 and 14.5% in Chile 4 .
COPD is considered a systemic inflammatory disease, with a poor correlation between airflow limitation, symptoms and prognosis 5,6 .Thus, incorporation of resources as PR, that improves tolerance of exercise, function of peripheral musquality of life, and reduces hospitalizations, is needed [6][7][8] .Therefore, the Ministry of Health in 2013 adapted a protocol of PR for Primary Health Care which consists on behavioral education and physical training 2 or 3 times a week for 3 months 9 .
Although PR is effective, studies have shown that it is not widely used.In Canada, 1.2% of patients with COPD had access to PR 10 .In Spain, 1-2% of hospitalizations by COPD had access to PR 11 .In the UK, 64% of patients with COPD fulfilled criteria to attend at PR 12 , similar to Denmark, where 67% fulfilled criteria 13 , however, solely 6% of patients were referred 12 .In France, 86% of patients with COPD had never participated in PR 14 .In addition, completion of PR in the UK reaches 40-60% of patients that begin PR 8,12 .In Canada, 80% of referred patients completed PR 10 .However, participation and completion of PR in Chile have not been determined.
Therefore, we aimed to determine participation and completion of patients with COPD in PR, in Chile, 2014-2016.

Study
A descriptive, observational, retrospective study was designed.

Population
National database of patients with COPD in treatment in Primary Health Care, obtained from Health Statistics and Information Department (DEIS), was used.Registers of patients with COPD between 2014-2016, and patients that attended and completed PR were included.Diseases different of COPD and activities in other programs of rehabilitation were excluded.

Measures
Variables were collected from an on line database, which included: patients with COPD in treatment, participation in PR, attendance assessment, age, gender, year of register and localization of patients.Attendance assessment was obtained in categories "completion" and "drop-out", being drop-out an attendance inferior to 17 sessions.Age in years was obtained in categories 40-54, 55-64, 65-74, and 75+.Localization of patients was determined in two dimensions: "region" and "Service of Health".

Statistic analysis
Measurement of the variables participation in PR, and attendance assessment was performed by absolute and relative frequency, depending on age, gender, year of register and localization.
Shapiro-Wilk Test was used to determine distribution of data at national level.For parametric data, mean±standard desviation were used.For nonparametric data, median and interquartile range were used.Outliers were deleted by software, specifically percentages of participation in PR over 15%, considering the maximum participation reported (14%) 14 .
Analyses were performed by SPSS 24 Software (IBM Corporation, Armonk, NY, USA) and Prism GraphPad 7.0 Software (GraphPad Software Inc, San Diego, CA, USA).

Patients with COPD in treatment between 2014-2016 were mainly 75+ years, female.
To characterize the population of patients with COPD, frequency of patients depending on age and gender was determined.A higher frequency in 75+ in 2014-2016 was observed (38.9, 39.5 and 40.4%, respectively), and a higher frequency of female patients in 2014-2016 was observed (54.7, 55.0 and 54.9%, respectively) [Table 1].

Percentage of patients with COPD that participated in PR between 2014-2016 was 2.9-2.4% at national level.
Considering the total of patients admitted in PR related to total of patients with COPD in treatment, at national level, we observed that 2.9% of patients with COPD participated in PR (IR= 2.0-4.7%) in 2014, 2.6% (IR= 2.0-3.6%) in 2015, and 2.4% (IR= 1.5-3.9%) in 2016 [Figure 1A].
The highest percentages of patients that participated in PR were observed in the north of Chile, with the highest percentage in Arica and Parinacota region in 2015 (9.5%) [Figure 2] and Arica Service of Health in 2015 (9.5%) (data not shown).

Discussion
These findings show that patients with COPD in treatment in Primary Health Care in Chile, between 2014-2016, were mainly 75+ years, female.At national level, the percentage of patients with COPD that participated in PR was 2.9-2.4%, and the percentage of patients that completed PR was 26.6-36.1%.
A study characterized these patients, indicating that 55.4% were female 15 , and a study performed in Chile indicated that 61.1% were > 60 years old 16 , which is similar to the current investigation.However, this differs from patients who attend RP, who are 65-74 years and male 8,12 .
International studies show low rates of referral to PR.In the UK, 6.0% of patients with COPD was referred 12 .In France, 14% of patients with COPD had participated in PR 14 .This results of participation are higher than the present results.Studies accomplished in Canada and Spain that show 1.2% and 1-2% of access to PR, respectively 10,11 , were performed 7 and 10 years ago, therefore, they are not current.This finding suggests the necessity of increasing the referral of patients with COPD to PR. Obstacles to refer have not been studied in Chile, therefore, these results support the necessity of studying these factors.
The current investigation showed a decreasing tendency in participation in PR.This could be related to professional training and characteristics of training 17 .
A study from the UK reported that 40-60% of patients completed PR 8,12 , which is higher to our results.In Canada, the reasons of drop-out were respiratory exacerbations and low rate of satisfaction 10 .In Argentina, a low adherence was reported (26.3%) and this was related to socioeconomic variables 18 .In Chile, reasons of drop-out have not been studied.These findings suggest the necessity of knowing those factors.
The present study has some weaknesses related to use of retrospective database and low accuracy of statistical registers, however, this information bias would have been reduced by studying total population and careful register.The availability of information related to characteristics of patients who participated in RP was a limitation of this study.
In conclusion, these findings are the first evidence of participation and completion of PR in COPD at national level.These results are relevant because they allow to evaluate the perfomance, utilisation and adherence to PR, and to focus the efforts towards improving the access.
Participación y adherencia a programas de rehabilitación pulmonar en pacientes con EPOC en Chile Participation and completion of pulmonary rehabilitation -A.Méndez et al Rev Med Chile 2018; 146: 1304-1308

figure 1 :figure 2 .
figure 1: Participation, completion and drop-out of PR at national level.A. Percentage of patients with COPD that participated in PR at national level depending on year of register.Data is presented as median and interquartile range.B. Percentage of patients with COPD who completed PR at national level depending on year of register.Data is presented as mean±SD.C. Percentage of patients with COPD who dropped out of PR at national level depending on year of register.Data is presented as median and interquartile range.All of data were calculated from percentage of patients with COPD admitted, who completed and who dropped out of PR in every region, therefore n=15.

Table 1 .
Demographic characterization of patients with COpD in treatment, Chile, 2014-2016