Figures
- Figure 1–
Summary of literature search and study selection.
Tables
- Table 1– Study and population characteristics of the selected studies of the systematic review
First author [ref.] Year Country Setting Patient population Study design Follow-up weeks Subjects n Female % Age mean±sd FEV1 % predicted mean±sd ≥3 measurement properties assessed Agusti [9] 2012 Spain Primary care and hospital Inpatient and outpatient Prospective cohort 4 377 7.2 NR NR da Silva [10] 2013 Brazil Hospital Outpatient Prospective cohort 1 50¶ 52.0 62.2±8.4 44.0±13.8 Dodd [11] 2011 England Primary and secondary care NR Prospective cohort 8 297 37.4 69.2±9.3 50.9±18.9 Jones [5] 2009 USA Primary care and pulmonary clinics Outpatient Prospective cohort 2 229 47.0 66.0±8.9 52.30±18.9 Jones [12] 2012 Canada and USA Primary care and pulmonary clinics Outpatient Prospective cohort 6 131 45.0 64.0±9.0+ 47.0±21.0+ Miravitlles [13] 2013 Spain Primary care and hospital Inpatient and outpatient Prospective cohort 6 486 11.8 69.4±9.5 47.7±17.4 Tsiligianni [14] 2012 Greece Primary and secondary care NR Prospective cohort 6 90 10.0 67.0 (58–75)§ NR Tsuda [15] 2012 Japan Patient database and panel Database or panel registrants Cross-sectional 301 22.9 55.9±10.6 NR 2 measurement properties assessed Dodd [16] 2012 England Pulmonary rehabilitation clinic Outpatient Prospective cohort 24 118 49.2 73.0±8.0 47.0 (33–67)§ Ghobadi [17] 2012 Iran NR NR Cross-sectional 105 0 59.6±11.9 71.0±26.7 Horita [18] 2014 Japan Hospital Outpatient Cross-sectional 85 17.6 71.9±8.9 45.8±14.7 Hwang [19] 2013 South Korea Primary care and hospital Outpatient Cross-sectional 100 3.0 69.2±8.4 63.6±21.1 Jones [20] 2011 Belgium, France, Germany, Italy, Netherlands, Spain and UK Primary care Outpatient Cross-sectional 1817 28.2 64.9±9.6 56.7±20.1 Jones [21]# 2012 Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey and UAE General population survey Survey participants Cross-sectional 6469 53.5 NR NR Jones [22] 2012 Belgium, France, Germany, Netherlands and Spain Primary care Outpatient Cross-sectional 2294 30.7 64.6±10.0 59.0±21.1 Kelly [23] 2012 England Hospital clinics Outpatient Prospective cohort NR 224 35.7 63.5±10.3 40.1±17.9 Kon [24] 2013 England Hospital Outpatient Prospective cohort 8 255 39.2 69.5±9.4 45.8±20.3 Kwon [25] 2013 Indonesia, Korea, Vietnam and Hong Kong Primary and secondary care Outpatient Cross-sectional 333 2.4 69.3±9.4 52.1±20.3 Mackay [26] 2012 England Previously existing COPD cohort study Outpatient Prospective cohort 5 161 39.8 71.3±9.4 50.3±16.9 Marchand [27] 2012 Belgium Tertiary care Outpatient Cross-sectional 213 37.0 63.0±10.0 47.0±20.0 Miyazaki [28] 2014 Japan Hospital Outpatient Prospective cohort NR 403 9.0 72.4±8.0 61.6±21.6 Zhou [29] 2013 China Pulmonary clinics, secondary and tertiary care NR Cross-sectional 6437 25.1 64.9±10.0 NR 1 measurement property assessed Al Moamary [30] 2011 Saudi Arabia Pulmonary rehabilitation clinic and pulmonary clinic Outpatient Prospective cohort 2 45 20.0 61.0±8.7 49.7±13.6 Al Moamary [31] 2012 Saudi Arabia, Kuwait, Bahrain, and UAE Pulmonary clinic Outpatient Cross-sectional 120 19.2 63.3±7.3 49.3±13.4 Feliz-Rodriguez [32] 2013 Spain Hospital Inpatient Prospective cohort 12 45 31.1 71.0±10.0 51.0±17.0 Gao [33] 2013 China Hospital Inpatient and outpatient Cross-sectional 263 15.2 66.7±7.4 47.43±14.3 Idrees [34]# 2012 Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey, UAE and Pakistan General population survey Survey participants Cross-sectional 1014 23.6 NR NR Kon [35] 2014 England Hospital and pulmonary clinics Inpatient and outpatient Prospective cohort 8 565ƒ 42.1 70.0±9.0 47.6 (45.9–49.3)## Nishimura [36] 2013 Japan Secondary care Healthy industrial workers Cross-sectional 1333 34.7 56.0±8.2 95.8±14.8 Okutan [37] 2013 Turkey Hospital Outpatient Cross-sectional 90 NR 68.5±10.9 NR Papaioannou [38] 2013 Greece Tertiary care Inpatient Prospective cohort 6 230 11.7 71.2±8.8 52.8±20.1 Polatli [39]# 2012 Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey, UAE and Pakistan General population survey Survey participants Cross-sectional 1392 24.4 NR NR Raghavan [40] 2012 Canada Random sample of general population Random sample participants Cross-sectional 532 53.0 60.1±11.4 98.0±17.0 Ringbaek [41] 2012 Denmark Secondary care Outpatient Cross-sectional 90 64.4 69.5±8.7 38.7±12.9 Uzaslan [42]# 2012 Algeria, Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, Syria, Tunisia, Turkey, UAE and Pakistan General population survey Survey participants Cross-sectional 1392 24.4 NR NR Varol [43] 2014 Turkey Hospital NR Cross-sectional 165 9.7 65.1±9.9 43.7±14.8 FEV1: forced expiratory volume in 1 s; NR: not reported; COPD: chronic obstructive pulmonary disease. #: references [21, 34, 39, 42] come from the same cross-sectional cohort (the BREATHE study); however, each reference evaluates different psychometric properties with varying subcohorts. ¶: reported population characteristics for face-to-face questionnaire group only, where the CAT was completed in a face-to-face interview. +: reported age and FEV1 for 67 subjects participating in study 1 of Jones [12]. §: data are presented as median (interquartile range). ƒ: reported population characteristics for 565 subjects participating in study 1 of Kon [35]. ##: data are presented as mean (95% CI).
- Table 2– COPD assessment test (CAT) nonresponse rate, floor and ceiling effect, internal consistency and test–retest reliability
Completed CATs and missing items 0 missing items % 1 missing item % Subjects n Agusti [9] 99.7 0.3 377 Ghobadi [17] 100 0.0 105 Jones [21]# 99.3 0.7 6469 Mackay [26] 98.3 1.7 161 Ringbaek [41] 98.9 1.1 90 Tsuda [15] 100 0.0 301 Floor¶ and ceiling+ effect Floor effect % Ceiling effect % Subjects n Agusti [9] 0.5 0.3 377 Nishimura [36] 0.0 7.6 145## Internal consistency§ Cronbach’s α Subjects n p-value Agusti [9] 0.86 NR NR da Silva [10] 0.98 50 0.001 Horita [18] 0.85 85 NR Hwang [19] 0.85 100 NR Jones [5] 0.88 1490 NR Jones [21] Arabic version 0.85 4807 NR Jones [21] Turkish version 0.86 1590 NR Tsiligianni [14] 0.86 90 NR Tsuda [15] 0.89 301 NR Test–retestƒ ICC n Administration duration weeks p-value 1 2 3 Agusti [9] 0.83 NR NR NR NR NR Al Moamary [30] 0.90 45 0 2 NA 0.00008 da Silva [10] 0.96 50 0 1 NA 0.93–0.97¶¶ Jones [5] 0.80 53 0 1 NA NR Tsiligianni [14] 0.94 90 0 2 6 0.92–0.96¶¶ COPD: chronic obstructive pulmonary disease; ICC: intra-class correlation coefficient; NR: not reported; NA: not applicable. #: missing defined as more than one item not completed so the questionnaire was considered unusable; if the score was missing for only one item, this was replaced by the mean value of the remaining seven items. ¶: percentage of patients with the minimum possible CAT total score (0/40). +: percentage of patients with the maximum possible (40/40). §: interrelatedness of the items within the CAT. ƒ: ability of the CAT to provide consistent scores over time when administered repeatedly under stable disease condition. ##: floor and ceiling effect of the CAT for COPD participants defined by fixed ratio. ¶¶: 95% CI for ICC estimate.
- Table 3– COPD assessment test (CAT) convergent and longitudinal validity
Instrument Studies n Convergent validity# Longitudinal validity¶ with study details Pearson’s correlation range Spearman’s correlation range Pearson’s correlation range Type of intervention/event Duration weeks Disease-specific questionnaires SGRQ-C 7 0.69–0.82 0.64 0.63 Exacerbation recovery 4 CCQ 4 NA NA 0.60 Exacerbation recovery 6 0.68–0.78 0.64–0.76 0.13 Pulmonary rehabilitation 8 SGRQ 5 0.72–0.74 0.65–0.84 0.36 Pulmonary rehabilitation 8 CRQ 5§ -0.48– -0.33 NA -0.50– -0.38 Pulmonary rehabilitation 6–8 General quality of life questionnaires SF-36 (general health) 1 0.58 NA SF-12 (physical component) 2 -0.60 -0.65 SF-12 (mental component) 2 -0.34 -0.58 SF-6D 1 -0.53 NA Clinical and physiological measures mMRC 11 0.29–0.61 0.42–0.61 0.20 Pulmonary rehabilitation 8 6MWT 4 -0.37– -0.27 -0.37– -0.24 FEV1 % predicted 10 -0.55– -0.17 -0.56– -0.23 COPD: chronic obstructive pulmonary disease; SGRQ: St George’s Respiratory Questionnaire; SGRQ-C: SGRQ for COPD; CCQ: Clinical COPD Questionnaire; CRQ: Chronic Respiratory Questionnaire; SF: Short Form; mMRC: modified Medical Research Council dyspnoea scale; 6MWT: 6-min walk test; FEV1: forced expiratory volume in 1 s; NA: not applicable. #: correlation between the total CAT score and the score of another instrument that measures a similar construct. ¶: correlation between the change in total CAT score and the change in score of another instrument over time with an intervention/event. §: Jones [12], Kon [24] and Al Moamary [31] had individual CRQ domain scores correlated to the total CAT score; therefore, individual correlations of the different domains were averaged to give a total CRQ correlation to the total CAT score.
- Table 4– COPD assessment test (CAT) known groups validity#
COPD GOLD grades GOLD I GOLD II GOLD III GOLD IV p-value Agusti [9] 12.4±NR 14.4±NR 20.9±NR 20.9±NR 0.01 Ghobadi [17] 14.6±NR 21.1±NR 25.1±NR 28.4±NR 0.001 Jones [20] 16.2±8.8 16.3±7.9 19.3±8.2 22.3±8.7 0.0001¶ Jones [22] 15.9±8.6 16.5±8.0 19.2±8.1 22.4±9.0 0.0001¶ Kwon [25] 16.5±NR 16.0±NR 19.0±NR 21.3±NR 0.001 Marchand [27] 14.3±NR 16.6±NR 19.1±NR 23.7±NR 0.0001¶ Okutan [37] 9.2±6.2 18.2±8.1 20.9±8.2 22.5±0.79 0.001+ Tsiligianni [14] 10.1±NR 10.5±NR 13.0±NR 26.0±NR 0.0023¶ Healthy individuals versus COPD No COPD COPD p-value Gao [33] 4.0±2.1 10.0±5.3 0.001 Jones [21] Turkey 8.1 (7.6–8.6)§ 20.9 (19.6–22.2)§ 0.0001 Jones [21] Arabic countries 5.4 (5.2–5.6)§ 16.6 (15.5–16.8)§ 0.0001 Miyazaki [28] 9.4±6.6 12.4±8.3 0.01 Nishimura [36] 5.8±4.4 7.3±5.2 0.001 Raghavan [40] 6.9±6.2 9.2±6.6 0.01 COPD status state Stable Exacerbation p-value Agusti [9] 15.8±8.1 22.4±8.4 0.01 Jones [5] 16.0±NR 20.7±NR 0.0001 Jones [20] 17.2±8.3 21.3±8.4 0.0001 mMRC score 0 1 2 3 4 p-value Agusti [9] 8.7±NR 14.8±NR 18.3±NR 24.9±NR 28.1±NR 0.01 Marchand [27] NA 12.7±NRƒ 19.9±NR 25.5±NR 25.2±NR 0.0001 Okutan [37] 7.7±2.2 13.9±6.1 21.7±5.9 27.5±2.2 27.3±9.7 0.021## Data are presented as subcategory total CAT score mean±sd, when available from the study, unless otherwise stated. COPD: chronic obstructive pulmonary disease; GOLD: Global Initiative for Chronic Obstructive Lung Disease; mMRC: modified Medical Research Council dyspnoea scale; NR: not reported; NA: not applicable. #: ability of the CAT to differentiate scores between subcategories known to vary on health status; ¶: GOLD I and GOLD II are not significant; +: GOLD II, GOLD III and GOLD IV are not significant; §: data are presented as mean (95% CI); ƒ: total CAT score for 0–1 mMRC score subcategory; ##: mMRC scores 2, 3 and 4 are not significant.
- Table 5– COPD assessment test (CAT) responsiveness# to pulmonary rehabilitation and exacerbation recovery on treatment
Study Duration weeks Study defined groups CAT score p-value Pre Post Change¶ Pulmonary rehabilitation Dodd [11] 8 NA 20.5±7.4 17.5±7.7 -2.9±NR 0.001 Dodd [16] 8 NA 22.1±7.5 19.2±7.6 -2.9±NR 0.001 Jones [12] 6 NA 17.9±6.5 15.7±6.9 -2.2±NR 0.002 Kon [24] 8 NA 21.8±7.2 18.8±7.4 -3.0±NR 0.001 Exacerbation recovery on treatment Agusti [9]+ 2 Much better NR NR -8.9±9.1 NR Considerably improved NR NR -4.8±6.0 NR Slightly improved NR NR -4.6±4.7 NR No change NR NR 0 NR Slightly worse NR NR 1.6±NR NR Quite a lot worse NR NR 4.7±NR NR Feliz-Rodriguez [32] 12 NA 22.8±4.9 15.6±4.5 -6.5±3.9 0.001 Jones [12] 4 NA 21.4±7.7 19.9±7.7 -1.4±5.3 0.03 Miravitlles [13] 6 NA 22.0±7.0 12.1±5.9 -9.9±5.1 0.001 Papaioannou [38] 6 Depressive symptoms NR NR -7.0±NR 0.012 No depressive symptoms NR NR -11.0±NR 0.012 Data are presented as mean±sd, when available from the study, unless otherwise stated. COPD: chronic obstructive pulmonary disease; NA: not applicable; NR: not reported. #: ability of the CAT to detect a change in score over time between interventions. ¶: negative change in CAT score is an improvement in CAT score (or health-related quality of life (HRQoL)); positive change in CAT score is a deterioration in CAT score (or HRQoL). +: categories of change determined based on the HRQoL transition.
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