ORIGINAL ARTICLE
Does type D personality affect symptom control and quality of life in asthma patients? Sung Reul Kim, Hyun Kyung Kim, Jeong Hee Kang, Seok Hee Jeong, Hye Young Kim, So Ri Kim and Mi Young Kim
Aims and objectives. This study aims to identify the effects of type D personality on symptom control and quality of life and to explore factors influencing quality of life among asthma patients in Korea. Background. Psychological factors such as depression and stress are well known to be related to medical outcomes and quality of life in asthma patients. People with type D personality are vulnerable to stress, show poor prognosis in disease and experience low quality of life. Design. A descriptive cross-sectional design was used. Methods. A total of 144 patients with asthma participated in this study. Data were collected through face-to-face interviews using structured questionnaires: the Type D Personality Scale-14, Asthma Control Test and Asthma-Specific Quality of Life. Results. About 33% of participants were classified into the type D personality group. The type D personality group showed statistically significantly lower symptom control and asthma-specific quality of life compared to the non-type D personality group. Based on forward stepwise multiple regression, the most significant factor of quality of life was symptom control, followed by type D personality, hospitalisation within the previous one year, and lifetime hospitalisation experiences. Conclusions. The prevalence of type D personality in asthma patients was high, and type D personality was significantly associated with poor symptom control and low quality of life. Psychosocial interventions might be beneficial to improve symptom control and quality of life in asthma patients with type D personality. Relevance to clinical practice. Nurses should be aware of the high prevalence of type D personality and the effects on symptom control and quality of life in asthma patients. Nurses should also provide personality-specific interventions to improve quality of life in such patients.
What does this paper contribute to the wider global clinical community?
• Type D personality is associated
•
with poor symptom control and low quality of life in asthma patients. Nurses need to provide personality-specific nursing interventions for asthma patients.
Authors: Sung Reul Kim, PhD, RN, Assistant Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Hyun Kyung Kim, PhD, RN, Associate Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Jeong Hee Kang, PhD, RN, Associate Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Seok Hee Jeong, PhD, RN, Assistant Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Hye Young Kim, PhD, RN, Assistant Professor, College of Nursing, Chonbuk Research
Institute of Nursing Science, Chonbuk National University, Jeonju; So Ri Kim, PhD, MD, Assistant Professor, Department of Internal Medicine, Research Center for Pulmonary Disorders, Chonbuk National University Medical School, Jeonju; Mi Young Kim, MSN, RN, Coordinator Nurse, Department of Nursing, Chonbuk National University Hospital, Jeonju, Korea Correspondence: Hyun Kyung Kim, Associate Professor, College of Nursing, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756, Korea. Telephone: +82 63 270 3121. E-mail: [email protected]
© 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748, doi: 10.1111/jocn.12667
739
SR Kim et al.
Key words: asthma, personality, quality of life, symptom Accepted for publication: 24 June 2014
Introduction Approximately 7–10% of people in the world suffer from asthma (Rowe et al. 2009). Asthma is a chronic inflammatory airway disease characterised by recurring and episodic wheezes, dyspnoea, chest tightness and cough (Global Initiative for Asthma, National Heart, Lung and Blood Institute 2006). Asthma is considered to be heterogeneous because its predisposing factors, symptoms and reactions to treatment vary across patients (Lazarus 2010). Psychological factors such as depression, anxiety and stress are well known to be related to medical outcomes including asthma symptoms, asthma attack and hospitalisation (Bosley et al. 1996, Trueba & Ritz 2013). In particular, stress has been reported as an important factor that predisposes individuals to asthma or aggravates its symptoms (Drummond & Hewson-Bower 1997, Turner Cobb & Steptoe 1998). Although the mechanism is not clear, stress has been estimated to increase inflammatory action and change sensitivity to infectious and systematic diseases by modifying the function of immune cells (Haczku et al. 2010, Trueba & Ritz 2013). In a previous study, perceived stress was a significant risk factor for self-reported onset of asthma and was highly related to hospitalisation of asthma patients (Rod et al. 2012). Another prospective population-based cohort study also found that various stressful life events, such as death or illness of a family member, marital problems, conflict with a supervisor, or financial difficulties, were associated with onset of asthma (Lietze0 n et al. 2011). In addition, intervention for stress reduction has been shown to be essential to symptom control and quality of life in asthma patients (Pokladnikova & Selke-Krulichova 2013). In this respect, identifying the level of stress in asthma patients or screening those who are vulnerable to stress should be conducted for stress management. Given that type D personality is related to higher levels of depression and anxiety as well as vulnerability to stress, and that asthma symptoms are affected by these psychosocial factors, asthma patients with type D personality are likely to be relatively susceptible to these factors. Because predisposing factors and symptoms of asthma are diverse across patients, identifying stress-related personality type could provide an essential cue for symptom control and quality of life in asthma patients.
740
Therefore, identifying the effects of type D personality on symptom control and quality of life in asthma patients could help nurses develop personality-specific interventions; however, little is known about these effects.
Background Research on the effects of stress-related personality type on chronic diseases has been steadily performed over the past several decades. Since type A personality, characterised by aggression, time-urgency, competitiveness, and sense of achievement, has been reported to be highly related to onset of cardiac diseases (Jenkins et al. 1974, Haynes & Feinleib 1982), its relations with other chronic diseases, such as asthma, liver diseases, tuberculosis, and kidney disease, have been explored (Rime et al. 1989). Type D personality was recently reported, and studies on its effects on cardiac and chronic diseases have been conducted (Song & Son 2008, Son et al. 2012). Type D personality, characterised by tendency to experience negative emotions (negative affectivity) and to inhibit expression (social inhibition), is vulnerable to negative affect including depression and anxiety (Denollet 2005). According to previous studies, people with type D personality are susceptible to chronic stress (Denollet 2000) and show poor prognosis in disease and low quality of life (Schiffer et al. 2008, Song & Son 2008). Martens et al. (2010) reported that type D personality was a strong predictor of adverse cardiac outcome after acute myocardial infarction (MI). Specifically, they saw a two-fold increased risk of death and/or recurrent MI and a more than threefold increased risk of late death and/or recurrent MI in such patients after adjustment for disease severity and depression. According to a meta-analysis, type D personality in cardiovascular patients was associated with two-fold increased odds for impaired physical health status and 25fold increased odds for impaired mental health status (Versteeg et al. 2012). In addition, type D personality was an independent predictor of health-related quality of life in patients with end-stage renal disease after adjustment for patient characteristics and depressive symptoms (Son et al. 2012). Type D patients with irritable bowel syndrome (IBS) showed significantly lower health-related quality of life compared to those with non-type D personality after © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
Original article
controlling for the influence of severity of IBS and duration of treatment (Sararoudi et al. 2011). Although asthma is highly related to stress, the prevalence of type D personality and medical outcomes and quality of life according to personality type have not been explored in asthma patients.
Study aims The aims of this study were to describe the prevalence of type D personality, to identify symptom control and quality of life according to personality type and to determine factors influencing quality of life in asthma patients.
Methods Study design A descriptive cross-sectional design was used.
Participants A convenience sample was recruited from the outpatient pulmonary medicine clinic of a tertiary hospital in Jeonju, Korea. The inclusion criteria were (1) 18 years of age or older and (2) asthma as a primary diagnosis confirmed by a pulmonologist according to the International Classification of Diseases and Related Health Problems 10th Revision (ICD-10). The exclusion criteria were (1) other major health problems that could influence the asthma condition and quality of life, such as active cancer, heart failure and renal failure, (2) COPD confirmed or suspected by a pulmonologist, and (3) surgery within the previous two months. A total of 144 patients with asthma participated in this study.
Measurements Type D personality Type D personality was measured using the Type D Personality Scale-14 (DS 14) developed by Denollet (2005) and translated into Korean by Lim et al. (2011). The scale included 14 items, each ranging from zero to four points. The scale consisted of two domains: negative affectivity and social inhibition. Participants who had a subtotal score equal to or greater than 10 for both domains were classified as type D personality. The reliability and validity of the Korean version of DS 14 have been well documented (Lim et al. 2011). Cronbach’s alpha of the original instrument was 088 for negative © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
Type D personality in asthma patients
affectivity and 082 for social inhibition (Denollet 2005). Cronbach’s alpha for the Korean version of the scale was 085 for negative affectivity and 087 for social inhibition (Lim et al. 2011). In the current study, Cronbach’s alpha was 084 for negative affectivity and 088 for social inhibition. Symptom control of asthma Symptom control of asthma was measured by the asthma control test (ACT), a patient-based index of asthma control (Nathan et al. 2004). The ACT has been cross-culturally validated (El Hasnaoui et al. 2009, Grammatopoulou et al. 2011, Uysal et al. 2013). The scale consisted of five items, and each item value ranged from one to five points. Lower scores indicated better control of asthma. Because there was no Korean version, the original instrument was translated after receiving permission from the original researcher. Forward translation from English to Korean was performed by two bilingual translators. Two sets of translations were integrated into a single survey by consensus of the two translators. Three bilingual nursing faculty members verified all items for semantic, empirical, and conceptual cross-cultural equivalence and revised them if needed. Finally, one pulmonary physician and one pulmonary nurse reviewed the instrument for clinical relevance and clarity. Cronbach’s alpha for the scale was 084 when developed (Nathan et al. 2004) and 067 in the present study. Asthma-specific quality of life Quality of life was measured using the Asthma-specific Quality of Life (A-QoL) scale developed for assessing health-related quality of life in Korean asthma patients (Lee et al. 2009). The scale consists of six subscales: physical and social activities, difficulties associated with cough, emotional status, breath-related symptoms, uncertain future and environmental distress. A total of 36 items were ranked on a five-point Likert scale. Higher scores indicated higher quality of life. Cronbach’s alpha for the scale was 095 when developed (Lee et al. 2009) and 096 in this study. Demographic and clinical characteristics Questions about demographic characteristics addressed sex, age, marital status, family living situation, and job conditions. Clinical characteristics included duration of asthma, number of oral medications, use of inhalant, use of rescue inhaler, use of immune therapy, lifetime hospitalisation experience, and hospitalisation experience within the previous one year.
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SR Kim et al.
Data collection One of the researchers, the coordinator nurse in the outpatient pulmonary medicine clinic selected patients who met the inclusion criteria of this study and fully informed them of its aims and procedures. All participants included in this study provided informed written consent. Data were collected by two research assistants through face-to-face interviews using the structured questionnaires. The research assistants read the questionnaires for participants and completed them according to their responses. Medical records were reviewed by the coordinator nurse for clinical characteristics. Data were collected between February–April 2013.
Ethical considerations This study was approved by the Institutional Review Board (IRB) of the hospital where this study was conducted. Written informed consent was obtained from all participants after fully explaining the aims and procedures of the study. The participants were also informed that they could voluntarily withdraw from the study at any point, and that collected data would be kept strictly confidential.
Data analysis Statistical analyses were conducted using SPSS, version 21.0 (IBM SPSS Statistics for Windows, Armonk, NY: IBM Corporation). Prevalence of type D personality, levels of symptom control and quality of life and characteristics of participants were analysed to obtain descriptive statistics. To compare the ACT, A-QOL and various characteristics between the type D personality group and the non-type D group, Chi-square tests, Mann–Whitney U tests, and ANCOVA tests (controlling for duration of disease and number of oral medications) were performed. The normality of the continuous variables was analysed using the Kolmogorov–Smirnov test. To identify the factors influencing A-QoL, a forward stepwise multiple regression was performed. Only the statistically significant variables revealed by the univariate analyses were included in the regression model. The statistical significance level was set at p < 005.
Results Demographic and clinical characteristics of participants Table 1 shows the demographic and clinical characteristics of the participants. The mean age of the participants was
742
6052 years (range: 18–83), and 639% of them were women. Seventy-five percent of participants had a spouse and 868% lived with their family. Only 382% of participants were employed. The mean duration of asthma was 777 years (range: 01–550), and the mean number of oral medications used within the previous one month was 256. About 90% of participants used inhalants, and 771% used rescue inhalers. In addition, 78% of participants received immune therapy. About 40% had a hospitalisation experience in their lifetimes, and 133% had the experience within the previous one year.
The prevalence of type D personality The mean score of DS14 was 1727 1491. The subscale scores for negative affectivity and social inhibition were 890 820 and 833 762, respectively. Of the participants, 327% were classified as having type D personality.
Comparison of demographic and clinical characteristics between the type D personality group and non-type D personality group Participants with type D personality had significantly longer duration of asthma than those with non-type D personality (z = 2206, p = 0027). The number of oral medications that the type D personality group used was significantly higher than that used by the non-type D personality group (z = 2207, p = 0043). Other characteristics, such as sex, age, marital status, family living situation, job, use of inhalant, use of rescue inhaler, immune therapy, lifetime hospitalisation experience, and hospitalisation experience within the previous one year, were not significantly different between the two groups (p > 005) (Table 1).
Comparison of symptom control (ACT) and quality of life (A-QoL) between the type D personality group and non-type D personality group Comparison of the mean scores of ACT and A-QoL between the type D personality group and the non-type D personality group are presented in Table 2. The ACT score of the type D personality group was significantly higher than that of the non-type D personality group (z = 4779, p < 0001). The A-QoL score of the type D personality group was significantly lower than that of the non-type D personality group (z = 6834, p < 0001), including all A-QoL domains. © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
Original article
Type D personality in asthma patients
Table 1 Demographic and clinical characteristics between the type D personality group and non-type D personality group (n = 144)
Variables
Total Mean SD or n (%) or Median (IQR)
Type D (n = 44) Mean SD or n (%) or Median (IQR)
Demographic characteristics Sex Male 52 (361) 13 (90) Female 92 (639) 31 (215) Age (years) 6052 1646 6138 1660 Marital status Married 108 (750) 32 (222) Others 36 (250) 12 (83) Family living situation Living together 125 (868) 35 (243) Alone 19 (132) 9 (63) Job Yes 55 (382) 14 (97) No 89 (618) 30 (208) Clinical characteristics 70 (30–120)† Duration of asthma (years) 50 (20–103)† † 3 (2–4)† Number of oral medications 3 (2–4) (within one month) Inhalant (n = 141) Yes 127 (901) 41 (291) No 14 (99) 3 (21) Rescue inhaler (n = 141) Yes 111 (771) 39 (277) No 30 (229) 6 (43) Immune therapy (n = 141) Yes 11 (78) 3 (21) No 130 (922) 41 (291) Lifetime hospitalisation experience (n = 143) Yes 57 (399) 24 (168) No 86 (601) 19 (133) Hospitalisation experience within the previous one year (n = 143) Yes 19 (133) 7 (49) No 124 (867) 36 (252)
Non-type D (n = 100) Mean SD or n (%) or Median (IQR)
39 (271) 61 (424) 6014 1647
z or v2
1184 0460
p
0347 0646*
76 (528) 24 (167)
0175
0681
90 (625) 10 (69)
2916
0110
41 (285) 59 (410)
1091
0354
40 (1–100)† 2 (2–3)†
2206 2207
0027* 0043*
86 (610) 11 (78)
0692
0549
72 (510) 24 (170)
2788
0127
8 (57) 89 (631)
0086
1000
33 (231) 67 (468)
1626
0256
12 (84) 88 (615)
0478
0592
IQR, Inter Quartile Range. *Tested using Mann–Whitney U test. † Median (IQR).
Symptom control (ACT) and quality of life (A-QoL) according to demographic and clinical characteristics Symptom control (ACT) and quality of life (A-QoL) according to demographic and clinical characteristics are summarised in Table 3 and Table 4. The mean ACT score of women was significantly higher than that of men (z = 2076, p = 0038). The ACT score was significantly lower in participants who received immune therapy (z = 2688, p = 0007) but higher in those who used rescue inhalers (z = 3188, p = 0001) than for those who did not. Participants with lifetime © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
hospitalisation experience (z = 2261, p = 0025) or hospital experience within the previous one year (z = 2324, p = 0020) showed significantly higher ACT scores compared to those without hospitalisation experience. The ACT score was significantly correlated with older age (r = 0199, p = 0017), longer duration of asthma (r = 0176, p = 0037), and higher number of oral medications (r = 0250, p = 0003). The mean A-QoL score in participants with jobs was significantly higher than for those without jobs (z = 2825, p = 0005). The mean A-QoL score of the participants who used rescue inhalers was significantly lower than for those
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SR Kim et al. Table 2 Comparison of symptom control (ACT) and quality of life (A-QoL) between the type D personality group and non-type D personality group
Variables
Total Mean SD
Symptom control (ACT) Quality of life (A-QoL) Physical and social activities Difficulties related to cough Emotional status Breath-related symptoms Uncertain future Environmental distress
1462 279 269 306 309 282 248 240
386 096 119 105 106 113 130 128
Type D (n = 44) Mean SD 1697 197 190 247 215 221 146 139
338 084 118 110 114 124 110 107
Non-type D (n = 100) Mean SD 1358 315 303 332 350 310 293 284
360 077 102 092 071 096 111 108
z
p
4779 6834 5296 4992 6937 4195 6338 6258
Does type D personality affect symptom control and quality of life in asthma patients? Sung Reul Kim, Hyun Kyung Kim, Jeong Hee Kang, Seok Hee Jeong, Hye Young Kim, So Ri Kim and Mi Young Kim
Aims and objectives. This study aims to identify the effects of type D personality on symptom control and quality of life and to explore factors influencing quality of life among asthma patients in Korea. Background. Psychological factors such as depression and stress are well known to be related to medical outcomes and quality of life in asthma patients. People with type D personality are vulnerable to stress, show poor prognosis in disease and experience low quality of life. Design. A descriptive cross-sectional design was used. Methods. A total of 144 patients with asthma participated in this study. Data were collected through face-to-face interviews using structured questionnaires: the Type D Personality Scale-14, Asthma Control Test and Asthma-Specific Quality of Life. Results. About 33% of participants were classified into the type D personality group. The type D personality group showed statistically significantly lower symptom control and asthma-specific quality of life compared to the non-type D personality group. Based on forward stepwise multiple regression, the most significant factor of quality of life was symptom control, followed by type D personality, hospitalisation within the previous one year, and lifetime hospitalisation experiences. Conclusions. The prevalence of type D personality in asthma patients was high, and type D personality was significantly associated with poor symptom control and low quality of life. Psychosocial interventions might be beneficial to improve symptom control and quality of life in asthma patients with type D personality. Relevance to clinical practice. Nurses should be aware of the high prevalence of type D personality and the effects on symptom control and quality of life in asthma patients. Nurses should also provide personality-specific interventions to improve quality of life in such patients.
What does this paper contribute to the wider global clinical community?
• Type D personality is associated
•
with poor symptom control and low quality of life in asthma patients. Nurses need to provide personality-specific nursing interventions for asthma patients.
Authors: Sung Reul Kim, PhD, RN, Assistant Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Hyun Kyung Kim, PhD, RN, Associate Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Jeong Hee Kang, PhD, RN, Associate Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Seok Hee Jeong, PhD, RN, Assistant Professor, College of Nursing, Chonbuk Research Institute of Nursing Science, Chonbuk National University, Jeonju; Hye Young Kim, PhD, RN, Assistant Professor, College of Nursing, Chonbuk Research
Institute of Nursing Science, Chonbuk National University, Jeonju; So Ri Kim, PhD, MD, Assistant Professor, Department of Internal Medicine, Research Center for Pulmonary Disorders, Chonbuk National University Medical School, Jeonju; Mi Young Kim, MSN, RN, Coordinator Nurse, Department of Nursing, Chonbuk National University Hospital, Jeonju, Korea Correspondence: Hyun Kyung Kim, Associate Professor, College of Nursing, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756, Korea. Telephone: +82 63 270 3121. E-mail: [email protected]
© 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748, doi: 10.1111/jocn.12667
739
SR Kim et al.
Key words: asthma, personality, quality of life, symptom Accepted for publication: 24 June 2014
Introduction Approximately 7–10% of people in the world suffer from asthma (Rowe et al. 2009). Asthma is a chronic inflammatory airway disease characterised by recurring and episodic wheezes, dyspnoea, chest tightness and cough (Global Initiative for Asthma, National Heart, Lung and Blood Institute 2006). Asthma is considered to be heterogeneous because its predisposing factors, symptoms and reactions to treatment vary across patients (Lazarus 2010). Psychological factors such as depression, anxiety and stress are well known to be related to medical outcomes including asthma symptoms, asthma attack and hospitalisation (Bosley et al. 1996, Trueba & Ritz 2013). In particular, stress has been reported as an important factor that predisposes individuals to asthma or aggravates its symptoms (Drummond & Hewson-Bower 1997, Turner Cobb & Steptoe 1998). Although the mechanism is not clear, stress has been estimated to increase inflammatory action and change sensitivity to infectious and systematic diseases by modifying the function of immune cells (Haczku et al. 2010, Trueba & Ritz 2013). In a previous study, perceived stress was a significant risk factor for self-reported onset of asthma and was highly related to hospitalisation of asthma patients (Rod et al. 2012). Another prospective population-based cohort study also found that various stressful life events, such as death or illness of a family member, marital problems, conflict with a supervisor, or financial difficulties, were associated with onset of asthma (Lietze0 n et al. 2011). In addition, intervention for stress reduction has been shown to be essential to symptom control and quality of life in asthma patients (Pokladnikova & Selke-Krulichova 2013). In this respect, identifying the level of stress in asthma patients or screening those who are vulnerable to stress should be conducted for stress management. Given that type D personality is related to higher levels of depression and anxiety as well as vulnerability to stress, and that asthma symptoms are affected by these psychosocial factors, asthma patients with type D personality are likely to be relatively susceptible to these factors. Because predisposing factors and symptoms of asthma are diverse across patients, identifying stress-related personality type could provide an essential cue for symptom control and quality of life in asthma patients.
740
Therefore, identifying the effects of type D personality on symptom control and quality of life in asthma patients could help nurses develop personality-specific interventions; however, little is known about these effects.
Background Research on the effects of stress-related personality type on chronic diseases has been steadily performed over the past several decades. Since type A personality, characterised by aggression, time-urgency, competitiveness, and sense of achievement, has been reported to be highly related to onset of cardiac diseases (Jenkins et al. 1974, Haynes & Feinleib 1982), its relations with other chronic diseases, such as asthma, liver diseases, tuberculosis, and kidney disease, have been explored (Rime et al. 1989). Type D personality was recently reported, and studies on its effects on cardiac and chronic diseases have been conducted (Song & Son 2008, Son et al. 2012). Type D personality, characterised by tendency to experience negative emotions (negative affectivity) and to inhibit expression (social inhibition), is vulnerable to negative affect including depression and anxiety (Denollet 2005). According to previous studies, people with type D personality are susceptible to chronic stress (Denollet 2000) and show poor prognosis in disease and low quality of life (Schiffer et al. 2008, Song & Son 2008). Martens et al. (2010) reported that type D personality was a strong predictor of adverse cardiac outcome after acute myocardial infarction (MI). Specifically, they saw a two-fold increased risk of death and/or recurrent MI and a more than threefold increased risk of late death and/or recurrent MI in such patients after adjustment for disease severity and depression. According to a meta-analysis, type D personality in cardiovascular patients was associated with two-fold increased odds for impaired physical health status and 25fold increased odds for impaired mental health status (Versteeg et al. 2012). In addition, type D personality was an independent predictor of health-related quality of life in patients with end-stage renal disease after adjustment for patient characteristics and depressive symptoms (Son et al. 2012). Type D patients with irritable bowel syndrome (IBS) showed significantly lower health-related quality of life compared to those with non-type D personality after © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
Original article
controlling for the influence of severity of IBS and duration of treatment (Sararoudi et al. 2011). Although asthma is highly related to stress, the prevalence of type D personality and medical outcomes and quality of life according to personality type have not been explored in asthma patients.
Study aims The aims of this study were to describe the prevalence of type D personality, to identify symptom control and quality of life according to personality type and to determine factors influencing quality of life in asthma patients.
Methods Study design A descriptive cross-sectional design was used.
Participants A convenience sample was recruited from the outpatient pulmonary medicine clinic of a tertiary hospital in Jeonju, Korea. The inclusion criteria were (1) 18 years of age or older and (2) asthma as a primary diagnosis confirmed by a pulmonologist according to the International Classification of Diseases and Related Health Problems 10th Revision (ICD-10). The exclusion criteria were (1) other major health problems that could influence the asthma condition and quality of life, such as active cancer, heart failure and renal failure, (2) COPD confirmed or suspected by a pulmonologist, and (3) surgery within the previous two months. A total of 144 patients with asthma participated in this study.
Measurements Type D personality Type D personality was measured using the Type D Personality Scale-14 (DS 14) developed by Denollet (2005) and translated into Korean by Lim et al. (2011). The scale included 14 items, each ranging from zero to four points. The scale consisted of two domains: negative affectivity and social inhibition. Participants who had a subtotal score equal to or greater than 10 for both domains were classified as type D personality. The reliability and validity of the Korean version of DS 14 have been well documented (Lim et al. 2011). Cronbach’s alpha of the original instrument was 088 for negative © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
Type D personality in asthma patients
affectivity and 082 for social inhibition (Denollet 2005). Cronbach’s alpha for the Korean version of the scale was 085 for negative affectivity and 087 for social inhibition (Lim et al. 2011). In the current study, Cronbach’s alpha was 084 for negative affectivity and 088 for social inhibition. Symptom control of asthma Symptom control of asthma was measured by the asthma control test (ACT), a patient-based index of asthma control (Nathan et al. 2004). The ACT has been cross-culturally validated (El Hasnaoui et al. 2009, Grammatopoulou et al. 2011, Uysal et al. 2013). The scale consisted of five items, and each item value ranged from one to five points. Lower scores indicated better control of asthma. Because there was no Korean version, the original instrument was translated after receiving permission from the original researcher. Forward translation from English to Korean was performed by two bilingual translators. Two sets of translations were integrated into a single survey by consensus of the two translators. Three bilingual nursing faculty members verified all items for semantic, empirical, and conceptual cross-cultural equivalence and revised them if needed. Finally, one pulmonary physician and one pulmonary nurse reviewed the instrument for clinical relevance and clarity. Cronbach’s alpha for the scale was 084 when developed (Nathan et al. 2004) and 067 in the present study. Asthma-specific quality of life Quality of life was measured using the Asthma-specific Quality of Life (A-QoL) scale developed for assessing health-related quality of life in Korean asthma patients (Lee et al. 2009). The scale consists of six subscales: physical and social activities, difficulties associated with cough, emotional status, breath-related symptoms, uncertain future and environmental distress. A total of 36 items were ranked on a five-point Likert scale. Higher scores indicated higher quality of life. Cronbach’s alpha for the scale was 095 when developed (Lee et al. 2009) and 096 in this study. Demographic and clinical characteristics Questions about demographic characteristics addressed sex, age, marital status, family living situation, and job conditions. Clinical characteristics included duration of asthma, number of oral medications, use of inhalant, use of rescue inhaler, use of immune therapy, lifetime hospitalisation experience, and hospitalisation experience within the previous one year.
741
SR Kim et al.
Data collection One of the researchers, the coordinator nurse in the outpatient pulmonary medicine clinic selected patients who met the inclusion criteria of this study and fully informed them of its aims and procedures. All participants included in this study provided informed written consent. Data were collected by two research assistants through face-to-face interviews using the structured questionnaires. The research assistants read the questionnaires for participants and completed them according to their responses. Medical records were reviewed by the coordinator nurse for clinical characteristics. Data were collected between February–April 2013.
Ethical considerations This study was approved by the Institutional Review Board (IRB) of the hospital where this study was conducted. Written informed consent was obtained from all participants after fully explaining the aims and procedures of the study. The participants were also informed that they could voluntarily withdraw from the study at any point, and that collected data would be kept strictly confidential.
Data analysis Statistical analyses were conducted using SPSS, version 21.0 (IBM SPSS Statistics for Windows, Armonk, NY: IBM Corporation). Prevalence of type D personality, levels of symptom control and quality of life and characteristics of participants were analysed to obtain descriptive statistics. To compare the ACT, A-QOL and various characteristics between the type D personality group and the non-type D group, Chi-square tests, Mann–Whitney U tests, and ANCOVA tests (controlling for duration of disease and number of oral medications) were performed. The normality of the continuous variables was analysed using the Kolmogorov–Smirnov test. To identify the factors influencing A-QoL, a forward stepwise multiple regression was performed. Only the statistically significant variables revealed by the univariate analyses were included in the regression model. The statistical significance level was set at p < 005.
Results Demographic and clinical characteristics of participants Table 1 shows the demographic and clinical characteristics of the participants. The mean age of the participants was
742
6052 years (range: 18–83), and 639% of them were women. Seventy-five percent of participants had a spouse and 868% lived with their family. Only 382% of participants were employed. The mean duration of asthma was 777 years (range: 01–550), and the mean number of oral medications used within the previous one month was 256. About 90% of participants used inhalants, and 771% used rescue inhalers. In addition, 78% of participants received immune therapy. About 40% had a hospitalisation experience in their lifetimes, and 133% had the experience within the previous one year.
The prevalence of type D personality The mean score of DS14 was 1727 1491. The subscale scores for negative affectivity and social inhibition were 890 820 and 833 762, respectively. Of the participants, 327% were classified as having type D personality.
Comparison of demographic and clinical characteristics between the type D personality group and non-type D personality group Participants with type D personality had significantly longer duration of asthma than those with non-type D personality (z = 2206, p = 0027). The number of oral medications that the type D personality group used was significantly higher than that used by the non-type D personality group (z = 2207, p = 0043). Other characteristics, such as sex, age, marital status, family living situation, job, use of inhalant, use of rescue inhaler, immune therapy, lifetime hospitalisation experience, and hospitalisation experience within the previous one year, were not significantly different between the two groups (p > 005) (Table 1).
Comparison of symptom control (ACT) and quality of life (A-QoL) between the type D personality group and non-type D personality group Comparison of the mean scores of ACT and A-QoL between the type D personality group and the non-type D personality group are presented in Table 2. The ACT score of the type D personality group was significantly higher than that of the non-type D personality group (z = 4779, p < 0001). The A-QoL score of the type D personality group was significantly lower than that of the non-type D personality group (z = 6834, p < 0001), including all A-QoL domains. © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
Original article
Type D personality in asthma patients
Table 1 Demographic and clinical characteristics between the type D personality group and non-type D personality group (n = 144)
Variables
Total Mean SD or n (%) or Median (IQR)
Type D (n = 44) Mean SD or n (%) or Median (IQR)
Demographic characteristics Sex Male 52 (361) 13 (90) Female 92 (639) 31 (215) Age (years) 6052 1646 6138 1660 Marital status Married 108 (750) 32 (222) Others 36 (250) 12 (83) Family living situation Living together 125 (868) 35 (243) Alone 19 (132) 9 (63) Job Yes 55 (382) 14 (97) No 89 (618) 30 (208) Clinical characteristics 70 (30–120)† Duration of asthma (years) 50 (20–103)† † 3 (2–4)† Number of oral medications 3 (2–4) (within one month) Inhalant (n = 141) Yes 127 (901) 41 (291) No 14 (99) 3 (21) Rescue inhaler (n = 141) Yes 111 (771) 39 (277) No 30 (229) 6 (43) Immune therapy (n = 141) Yes 11 (78) 3 (21) No 130 (922) 41 (291) Lifetime hospitalisation experience (n = 143) Yes 57 (399) 24 (168) No 86 (601) 19 (133) Hospitalisation experience within the previous one year (n = 143) Yes 19 (133) 7 (49) No 124 (867) 36 (252)
Non-type D (n = 100) Mean SD or n (%) or Median (IQR)
39 (271) 61 (424) 6014 1647
z or v2
1184 0460
p
0347 0646*
76 (528) 24 (167)
0175
0681
90 (625) 10 (69)
2916
0110
41 (285) 59 (410)
1091
0354
40 (1–100)† 2 (2–3)†
2206 2207
0027* 0043*
86 (610) 11 (78)
0692
0549
72 (510) 24 (170)
2788
0127
8 (57) 89 (631)
0086
1000
33 (231) 67 (468)
1626
0256
12 (84) 88 (615)
0478
0592
IQR, Inter Quartile Range. *Tested using Mann–Whitney U test. † Median (IQR).
Symptom control (ACT) and quality of life (A-QoL) according to demographic and clinical characteristics Symptom control (ACT) and quality of life (A-QoL) according to demographic and clinical characteristics are summarised in Table 3 and Table 4. The mean ACT score of women was significantly higher than that of men (z = 2076, p = 0038). The ACT score was significantly lower in participants who received immune therapy (z = 2688, p = 0007) but higher in those who used rescue inhalers (z = 3188, p = 0001) than for those who did not. Participants with lifetime © 2014 John Wiley & Sons Ltd Journal of Clinical Nursing, 24, 739–748
hospitalisation experience (z = 2261, p = 0025) or hospital experience within the previous one year (z = 2324, p = 0020) showed significantly higher ACT scores compared to those without hospitalisation experience. The ACT score was significantly correlated with older age (r = 0199, p = 0017), longer duration of asthma (r = 0176, p = 0037), and higher number of oral medications (r = 0250, p = 0003). The mean A-QoL score in participants with jobs was significantly higher than for those without jobs (z = 2825, p = 0005). The mean A-QoL score of the participants who used rescue inhalers was significantly lower than for those
743
SR Kim et al. Table 2 Comparison of symptom control (ACT) and quality of life (A-QoL) between the type D personality group and non-type D personality group
Variables
Total Mean SD
Symptom control (ACT) Quality of life (A-QoL) Physical and social activities Difficulties related to cough Emotional status Breath-related symptoms Uncertain future Environmental distress
1462 279 269 306 309 282 248 240
386 096 119 105 106 113 130 128
Type D (n = 44) Mean SD 1697 197 190 247 215 221 146 139
338 084 118 110 114 124 110 107
Non-type D (n = 100) Mean SD 1358 315 303 332 350 310 293 284
360 077 102 092 071 096 111 108
z
p
4779 6834 5296 4992 6937 4195 6338 6258
