Open Access

Trends in adult asthma hospitalization: gender-age effect

  • Francisco J Gonzalez-Barcala1Email author,
  • Jorge Aboal2,
  • Luis Valdes3,
  • José M Carreira4,
  • Jose M Alvarez-Dobaño3,
  • Amalia Puga5,
  • María Teresa Garcia-Sanz1 and
  • Bahi Takkouche6
Multidisciplinary Respiratory Medicine20116:82

DOI: 10.1186/2049-6958-6-2-82

Received: 8 June 2010

Accepted: 6 September 2010

Published: 30 April 2011

Abstract

Background

Hospital admissions due to asthma are a reliable source of information on the morbidity of the disease which, after the increase observed in the last quarter of the last century, shows a declining trend in the last few years. The aim of this study was to look at hospital admission trends due to asthma in our community and analyze some of its associated factors.

Methods

Retrospective analysis of all hospital admissions involving adults aged 15 years and older with asthma as the primary or secondary diagnosis (if the first diagnosis was respiratory failure or respiratory infection) in Public Health Service hospitals in the Galician region of Spain between the years 1995-2009 (total 24,766 admissions).

Results

The majority of patients admitted were female (71%), over 60 years of age (64%), and admission occurred predominantly in the winter months. The hospitalization rate due to asthma tripled over the period studied, this being mainly accounted for by women aged over 60 years. Mean hospital stay was 9.2 days, longer in older patients or those admitted over the weekend.

Conclusions

A significant increase in hospital admissions due to asthma over the last few years has been observed in our community, mainly involving older women. The mean stay seems long, increasing with patients' age and admission over the weekend.

Keywords

Asthma hospital admission hospitalization trends

Trend di ospedalizzazione nell’asma dell’adulto: effetto di età e genere

Riassunto

Razionale

I ricoveri ospedalieri dovuti ad asma sono una fonte d’informazione attendibile sulla morbilità della patologia che, dopo un incremento osservato nell’ultimo quarto del secolo scorso, è in fase di declino negli ultimi anni. Scopo di questo studio era descrivere i trend di ospedalizzazione per asma nella nostra comunità ed analizzare alcuni dei fattori associati.

Metodi

Analisi retrospettiva di tutte le ospedalizzazioni di adulti dai 15 anni in su per asma come diagnosi primaria, o come diagnosi secondaria in caso la prima diagnosi fosse insufficienza respiratoria o un’infezione respiratoria, in ospedali pubblici della regione Galizia della Spagna tra gli anni 1995 e 2009 (totale dei ricoveri: 24.766).

Risultati

La maggioranza dei pazienti ricoverati erano femmine (71%), di età superiore a 60 anni (64%) e la maggior parte degli accessi avveniva nella stagione invernale.

Il tasso di ospedalizzazione per asma è triplicato nel periodo studiato, soprattutto per le donne di età superiore a 60 anni. La durata media del ricovero era di 9,2 giorni, più prolungata nei pazienti più anziani ed in coloro che erano ricoverati nel fine settimana.

Conclusioni

Un significativo incremento delle ospedalizzazioni per asma negli ultimi anni è stato osservato nella nostra comunità, soprattutto a carico delle donne più anziane. La durata media del ricovero appare lunga ed aumenta con l’età del paziente e nei ricoveri del fine settimana.

Keywords

Asthma hospital admission hospitalization trends

Parole chiave

Asma ospedalizzazione ricovero trend

Introduction

Asthma affects 300 million people in the world, with a prevalence greater than 10% in developed countries and 180,000 deaths per year attributable to the disease [1]. Hospital admissions due to asthma are one of the best sources of information on trends and prognosis in the morbidity of the disease [2, 3], but there is no data available in many countries [2].

During the last quarter of the last century an increasing trend in asthma-related hospital admissions has been observed, although in the last few years this trend seems to be changing [4, 5]; however, there are significant differences between countries as well as between sexes and age groups [2, 5]. Hospital admissions due to asthma are affected by various interacting factors. Firstly, there can be changes in the diagnosis and coding systems, although when this is the cause, it is usually obvious as a drastic change is seen in trends. Secondly, changes in health care can have an influence: these can be in terms of access to the health system or treatment availability, or the education of the population. Lastly, changes in hospital admissions due to asthma may be caused by changes in the prevalence or severity of the disease [2, 6, 7].

The purpose of this study was to describe, in the adult population of our community, hospital admission trends due to asthma. Another aim was to characterize the epidemiology of this condition, analyzing differences due to age and sex, as well as the duration of the hospital stay, and identify some of the determining factors of these.

Material and methods

We retrospectively analyzed all the admissions due to asthma occurring in Public Health Service hospitals in our region (Galician Health Service, Spain), between the years 1995 and 2009. From the information collected from the Clinical Records Department, all patients with asthma as the primary or secondary diagnosis (if the first diagnosis was respiratory failure or respiratory infection) were included. The age and sex, date of admission and length of hospital stay of each patient was analyzed. To evaluate the effect of admissions over the weekend, the days of the week were grouped into two categories, one with admissions occurring between Monday and Thursday, the other with admissions from Friday to Sunday.

In our Autonomous Community, according to the 2002 population census, there were 2,420,303 inhabitants (47.6% males) aged 15 years or over [8]. Around 98% of these had public health system cover, leaving a small percentage excluded, with private health insurance.

The Review Board on Human Studies at our institution approved the protocol.

Statistical analysis

The data were tested for normal distribution using the Kolmogorov-Smirnov test. Student's t test was used for the comparison of the two category continuous variables when these had a normal distribution, and the Mann Whitney U test when they had a non-parametric distribution. For the comparison of continuous variables of more than two categories we used ANOVA for the normal distribution variables and the Kruskal Wallis test when the distribution was non-Gaussian. Comparison of the categorical variables was performed using the chi-squared test. The adjusted odds ratios of the increase in mean hospital stay were calculated as a function of sex, age, and admission during the week or weekend. All statistical analyses were performed using the SPSS 15 statistics program.

Results

During the 15-year period under analysis, there were 24,766 admissions (70.9% female) to our hospitals with asthma as the primary or secondary diagnosis (Table 1). About two thirds of the patients were over 60 years old (Table 2). The mean age of the females was 64 years, significantly higher than the 54 years for males (data not shown). The hospitalization rates per 100,000 inhabitants increased progressively throughout the period studied, from 38.2/100,000 in 1995 to 81.8/100,000 in 2009 (Table 1). The most significant increase was seen in women over 60 years, although an increasing trend was observed in all the age and sex groups (Figure 1). There was a clear predominance in admissions during the winter months, with an admission maximum in January, followed by December. Admissions were least during the months of July and August (Figure 2).
Table 1

Number of asthma-related hospital admissions in the galician region of spain 1995-2009, by year

 

Total admissions

Total rate

Male admissions (%)

Male rate

Female admissions (%)

Female rate

p

1995

925

38.22

317 (34.3)

27.47

608 (65.7)

48.01

0.0001

1996

1103

45.57

392 (35.5)

33.97

711 (64.5)

56.14

0.0001

1997

1269

52.43

413 (32.5)

35.79

856 (67.5)

67.59

0.0001

1998

1241

51.27

393 (31.7)

34.06

848 (68.3)

66.96

0.0001

1999

1703

70.36

528 (31.0)

45.76

1175 (69)

92.77

0.0001

2000

1803

74.49

573 (31.8)

49.66

1230 (68.2)

97.12

0.0001

2001

1352

55.86

440 (32.5)

38.14

912 (67.5)

72.01

0.0001

2002

1646

68.01

457 (27.8)

39.61

1189 (72.2)

93.88

0.0001

2003

1850

76.44

541(29.2)

46.89

1309 (70.8)

103.35

0.0001

2004

1646

68.01

437 (26.5)

37.88

1209 (73.5)

95.46

0.0001

2005

1801

74.41

452 (25.1)

39.18

1349 (74.9)

106.51

0.0001

2006

1720

71.07

466 (27.1)

40.39

1254 (72.9)

99.01

0.0001

2007

1803

74.49

458 (25.4)

39.70

1345 (74.6)

106.20

0.0001

2008

1830

75.61

444 (24.3)

38.48

1386 (75.7)

109.43

0.0001

2009

1979

81.77

522 (26.4)

45.24

1457 (73.6)

115.04

0.0001

Total

24766

1023.26

7212 (29.1)

625.07

17554 (70.9)

1386.01

0.0001

p: comparison male vs female.

Rate: rate per 100,000 population.

Table 2

Number of asthma-related hospital admissions in the galician region of spain 1995-2009, by age group

 

Admissions age 15-39 years n (%)

Rate

Admissions 40-59 years n (%)

Rate

Admissions ≥ 60 years n (%)

Rate

p

1995

207 (22.4)

20.84

214 (23.1)

30.08

504 (54.5)

70.43

0.0001

1996

263 (23.8)

26.48

257 (23.3)

36.12

583 (52.9)

81.47

0.0001

1997

327 (25.8)

32.92

262 (20.6)

36.82

680 (53.6)

95.03

0.0001

1998

300 (24.2)

30.21

237 (19.1)

33.31

704 (56.7)

98.38

0.0001

1999

341 (20.0)

34.33

369 (21.7)

51.86

993 (58.3)

138.77

0.0001

2000

361 (20.0)

36.35

351 (19.5)

49.33

1091 (60.5)

152.47

0.0001

2001

289 (21.4)

29.10

246 (18.2)

34.57

817 (60.4)

114.17

0.0001

2002

274 (16.6)

27.59

297 (18.0)

41.74

1075 (65.3)

150.23

0.0001

2003

380 (20.5)

38.26

317 (17.1)

44.55

1153 (62.3)

161.13

0.0001

2004

263 (16.0)

26.48

288 (17.5)

40.47

1095 (66.5)

153.02

0.0001

2005

248 (13.8)

24.97

301 (16.7)

42.30

1252 (69.5)

174.97

0.0001

2006

235 (13.7)

23.66

272 (15.8)

38.23

1213 (70.5)

169.51

0.0001

2007

236 (13.1)

23.76

251 (13.9)

35.27

1316 (73.0)

183.91

0.0001

2008

244 (13.3)

24.57

263 (14.4)

36.96

1323 (72.3)

184.89

0.0001

2009

321 (16.2)

32.32

309 (15.6)

43.43

1349 (68.2)

188.52

0.0001

Total

4289 (18.1)

431.85

4234 (17.9)

595.04

15148 (64.0)

2116.91

0.0001

p: comparison between age groups.

n (%): number of admissions (percentage for each year).

Rate: rate per 100,000 population.

https://static-content.springer.com/image/art%3A10.1186%2F2049-6958-6-2-82/MediaObjects/40248_2010_Article_258_Fig1_HTML.jpg
Figure 1

Trends in asthma hospital admissions from 1995 to 2009, by age and sex group.

https://static-content.springer.com/image/art%3A10.1186%2F2049-6958-6-2-82/MediaObjects/40248_2010_Article_258_Fig2_HTML.jpg
Figure 2

Asthma hospital admissions by month. Mean: monthly mean of admission.

The mean hospital stay was 9.2 days, with a median of 7 days (Table 3). Increased age and weekends were associated with longer stays (Table 3).
Table 3

Table 3a. Asthma-related hosiptal stay in the galician region of spain, univariate analysis.

  

Mean Hospital Stay* (SD)

p

Sex

Male

8.6 (8.8)

0.0001

 

Female

9.4 (8.7)

 

Age (years)

15-39

5.7 (5.5)

0.0001

 

40-59

8.4 (10.5)

 
 

≥ 60

10.4 (8.6)

 

Weekday

Monday-Thursday

9.1 (8.9)

NS

 

Friday-Sunday

9.3 (8.4)

 
 

Total

9.2 (8.7)

 

Table 3b. Adjusted odds ratio of hospital stay over the mean, by sex, age group and weekday of admission

  

Odds Ratio

CI 95%

Sex

Male

1

 
 

Female

1.05

0.99-1.12

Age

15-39

1

 
 

40-59

2.93

2.62-3.29

 

≥ 60

5.59

5.07-6.17

Weekday

Monday-Thursday

1

 
 

Friday-Sunday

1.33

1.25-1.40

Comparison by sex, age group and weekday of admission

*Hospital stay in days.

Definition of abbreviations: SD, standard deviation; NS, not significant.

Definition of abbreviation: Cl, Confidence interval.

Discussion

Hospital admissions due to asthma can be a reliable indicator of how the morbidity of this disease is evolving, although many countries still do not have such data available [2]. In our region of Spain, there has been a significant increase in hospital admissions due to asthma over the last 15 years, mainly accounted for by women over 60 years of age. This is the opposite of what is seen in most developed countries, where there is a decreasing trend [3]. Another exception among developed countries is Holland, where hospital admissions due to acute exacerbation of asthma continue to rise, despite the high sales of inhaled corticosteroids [2].

The admission rates (from 18.1/100,000 inhabitants in the population aged 15-39 years, to 64.0/100,000 in the population aged over 60 years) are particularly high compared with other populations in the western world [5, 9, 10].

The reasons for the increase in hospitalizations could be related to several factors. One could be an increase in the prevalence or severity of the disease, which seems very likely, based on data available for the Spanish population, both in children and young adults, which show an increase over the last few years [11, 12]. Another possible cause could be the increase in exacerbations of asthma due to poor control of the disease. In this sense, the level of control of asthma in the Spanish population still appears to be insufficient, as only 36.1% of the Spanish asthmatic population are said to be adequately controlled, although we do not know the situation during the initial period of our study [13]. A third factor could be changes in medical practice in making the decision to admit to hospital. We have no data available on this aspect, but the widespread use of asthma management guidelines should, on the contrary, produce a decrease in asthma-related admissions [14]. Lastly, the increase in hospitalizations could be due to there being a wider classification of patients with asthma due to an increase in knowledge of the disease, as has been pointed out in various studies [12].

The admission peaks in the winter period are in agreement with other observations in the literature, associated mainly with viral infections, which are the most common cause of acute exacerbation of asthma [3, 15, 16].

The mean hospital stay in our population is not a very positive finding, being much higher than that observed by other authors [5, 9, 17, 18]. Older age and weekend admissions are independent predictors of longer hospital stays. Being female is associated with longer hospital stays (than for males), but this significance is lost in the multivariate analysis, probably due to the higher mean age of the women admitted.

The increased morbidity (testified both by the number of admissions and the longer hospital stays) of asthma in women is in line with what is seen in other countries. Several factors may lead to a higher rate of female admissions: a higher prevalence of asthma in women than in males [19, 20]; a greater expression of symptoms of the disease in females [21]; the fact that women are normally more exposed than men to cleaning products and other irritants [22, 23]; higher female life expectancy, making their admission due to asthma more likely [18], despite adjustment for age and severity [24].

The increase in hospital stay with age has been described in other populations [9, 25]. Increased morbidity [15, 26] or the claim that these patients have a poorer response to treatment are also mentioned as causes [17].

The negative influence of weekend admissions has been associated with longer stays in other illnesses [27, 28], and even with a higher mortality [29, 30]. Possible causes could be the fact that fewer people work in hospitals on weekends than on weekdays, and those who do work on weekends often have less seniority and experience than those who work on weekdays [29]. The patients may also have different characteristics that might complicate their progression, such as a higher frequency of drugs taken abusively [30].

A limitation of this study is that the diagnosis and severity of asthma were not checked individually. In any case, the data used in this study are based on the diagnosis reached by the treating specialist. This should not affect the admission trends or hospital stays, since the same methodology was used for all subjects throughout the study period.

In conclusion, the main findings of our study are: 1) the progressive increase in the number of hospital admissions due to asthma throughout the period studied, mainly accounted for by women over 60 years; 2) that hospital stays in our population - particularly for older patients or those admitted at the weekend - are longer than in other populations.

Conflict of interest statement

None of the authors has any conflict of interest to declare in relation to the subject matter of this manuscript.

Authors’ Affiliations

(1)
Servicio de Neumologia, Hospital de Pontevedra
(2)
Servicio de Admision y Documentacion Clinica, Hospital Clinico Universitario
(3)
Servicio de Neumologia, Hospital Clinico Universitario
(4)
Departamento de Radiología, Universidad de Santiago de Compostela, Santiago de Compostela
(5)
Departamento de Enfermeria, Universidad de Santiago de Compostela, Santiago de Compostela
(6)
Departamento de Medicina Preventiva, Universidad de Santiago de Compostela

References

  1. Braman SS: The global burden of asthma. Chest. 2006, 130 (1 Suppl): 4S-12S.View ArticlePubMedGoogle Scholar
  2. Gupta R, Anderson HR, Strachan DP, Maier W, Watson L: International trends in admissions and drug sales for asthma. Int J Tuberc Lung Dis. 2006, 10: 138-145.PubMedGoogle Scholar
  3. Sears MR: Epidemiology of asthma exacerbations. J Allergy Clin Immunol. 2008, 122: 662-668. 10.1016/j.jaci.2008.08.003.View ArticlePubMedGoogle Scholar
  4. Anderson HR, Gupta R, Strachan DP, Limb ES: 50 years of asthma: UK trends from 1955 to 2004. Thorax. 2007, 62: 85-90. 10.1136/thx.2006.066407.PubMed CentralView ArticlePubMedGoogle Scholar
  5. Singleton RJ, Holman RC, Cobb N, Curns AT, Paisano EL: Asthma hospitalizations among American Indian and Alaska Native people and for the general US population. Chest. 2006, 130: 1554-1562. 10.1378/chest.130.5.1554.View ArticlePubMedGoogle Scholar
  6. Wilson DH, Tucker G, Frith P, Appleton S, Ruffin RE, Adams RJ: Trends in hospital admissions and mortality from asthma and chronic obstructive pulmonary disease in Australia, 1993-2003. Med J Aust. 2007, 186: 408-411.PubMedGoogle Scholar
  7. Morrison DS, McLoone P: Changing patterns of hospital admission for asthma, 1981-97. Thorax. 2001, 56: 687-690. 10.1136/thorax.56.9.687.PubMed CentralView ArticlePubMedGoogle Scholar
  8. [http://www.ine.es]
  9. Pascal L, Fuhrman C, Durif L, Nicolau J, Charpin D, Dujols P, Delmas MC: Trends in hospital admissions for asthma in France, 1998-2002. Rev Mal Respir. 2007, 24: 581-590. 10.1016/S0761-8425(07)91125-0.View ArticlePubMedGoogle Scholar
  10. Haahtela T, Tuomisto LE, Pietinalho A, Klaukka T, Erhola M, Kaila M, Nieminen MM, Kontula E, Laitinen LA: A 10 year asthma programme in Finland: major change for the better. Thorax. 2006, 61: 663-670. 10.1136/thx.2005.055699.PubMed CentralView ArticlePubMedGoogle Scholar
  11. García-Marcos L, Quirós AB, Hernández GG, Guillén-Grima F, Díaz CG, Ureña IC, Pena AA, Monge RB, Suárez-Varela MM, Varela AL, Cabanillas PG, Garrido JB: Stabilization of asthma prevalence among adolescents and increase among schoolchildren (ISAAC phases I and III) in Spain. Allergy. 2004, 59: 1301-1307. 10.1111/j.1398-9995.2004.00562.x.View ArticlePubMedGoogle Scholar
  12. Urrutia I, Aguirre U, Sunyer J, Plana E, Muniozguren N, Martínez-Moratalla J, Payo F, Maldonado JA, Anto JM, Estudio de Salud Respiratoria de la Comunidad Europea: Changes in the prevalence of asthma in the Spanish cohort of the European Community Respiratory Health Survey (ECRHS-II). Arch Bronconeumol. 2007, 43: 425-430.View ArticlePubMedGoogle Scholar
  13. González Barcala FJ, de la Fuente-Cid R, Alvarez-Gil R, Tafalla M, Nuevo J, Caamaño-Isorna F: Factors associated with asthma control in primary care patients: the CHAS study. Arch Bronconeumol. 2010, 46: 358-363.View ArticlePubMedGoogle Scholar
  14. Rowe BH, Chahal AM, Spooner CH, Blitz S, Senthilselvan A, Wilson D, Holroyd BR, Bullard M: Increasing the use of anti-inflammatory agents for acute asthma in the emergency department: experience with an asthma care map. Can Respir J. 2008, 15: 20-26.PubMed CentralPubMedGoogle Scholar
  15. Watson L, Turk F, James P, Holgate ST: Factors associated with mortality after an asthma admission: a national United Kingdom database analysis. Respir Med. 2007, 101: 1659-1664. 10.1016/j.rmed.2007.03.006.View ArticlePubMedGoogle Scholar
  16. Sykes A, Johnston SL: Etiology of asthma exacerbations. J Allergy Clin Immunol. 2008, 122: 685-688. 10.1016/j.jaci.2008.08.017.View ArticlePubMedGoogle Scholar
  17. Banerji A, Clark S, Afilalo M, Blanda MP, Cydulka RK, Camargo CA: Prospective multicenter study of acute asthma in younger versus older adults presenting to the emergency department. J Am Geriatr Soc. 2006, 54: 48-55. 10.1111/j.1532-5415.2005.00563.x.View ArticlePubMedGoogle Scholar
  18. Chen Y, Stewart P, Johansen H, McRae L, Taylor G: Sex difference in hospitalization due to asthma in relation to age. J Clin Epidemiol. 2003, 56: 180-187. 10.1016/S0895-4356(02)00593-0.View ArticlePubMedGoogle Scholar
  19. Butland BK, Strachan DP, Rudnicka AR: C-reactive protein, obesity, atopy and asthma symptoms in middle-aged adults. Eur Respir J. 2008, 32: 77-84. 10.1183/09031936.00077207.View ArticlePubMedGoogle Scholar
  20. Sunyer J, Antó JM, Kogevinas M, Barceló MA, Soriano JB, Tobías A, Muniozguren N, Martínez-Moratalla J, Payo F, Maldonado JA: Risk factors for asthma in young adults. Spanish Group of the European Community Respiratory Health Survey. Eur Respir J. 1997, 10: 2490-2494. 10.1183/09031936.97.10112490.View ArticlePubMedGoogle Scholar
  21. Schatz M, Clark S, Camargo CA: Sex differences in the presentation and course of asthma hospitalizations. Chest. 2006, 129: 50-55. 10.1378/chest.129.1.50.View ArticlePubMedGoogle Scholar
  22. Mendonça EM, Algranti E, de Freitas JB, Rosa EA, dos Santos Freire JA, de Paula Santos Ud U, Pinto J, Bussacos MA: Occupational asthma in the city of São Paulo, 1995-2000, with special reference to gender analysis. Am J Ind Med. 2003, 43: 611-617. 10.1002/ajim.10210.View ArticlePubMedGoogle Scholar
  23. Dimich-Ward H, Camp PG, Kennedy SM: Gender differences in respiratory symptoms-does occupation matter?. Environ Res. 2006, 101: 175-183. 10.1016/j.envres.2005.02.008.View ArticlePubMedGoogle Scholar
  24. Baibergenova A, Thabane L, Akhtar-Danesh N, Levine M, Gafni A, Leeb K: Sex differences in hospital admissions from emergency departments in asthmatic adults: a population-based study. Ann Allergy Asthma Immunol. 2006, 96: 666-672. 10.1016/S1081-1206(10)61063-0.View ArticlePubMedGoogle Scholar
  25. Skobeloff EM, Spivey WH, St Clair SS, Schoffstall JM: The influence of age and sex on asthma admissions. JAMA. 1992, 268: 3437-3440. 10.1001/jama.1992.03490240045034.View ArticlePubMedGoogle Scholar
  26. Thomas SD, Whitman S: Asthma hospitalizations and mortality in Chicago: an epidemiologic overview. Chest. 1999, 116 (4 Suppl 1): 135S-141S.View ArticlePubMedGoogle Scholar
  27. Ananthakrishnan AN, McGinley EL, Saeian K: Outcomes of weekend admissions for upper gastrointestinal hemorrhage: a nationwide analysis. Clin Gastroenterol Hepatol. 2009, 7: 296-302e1. 10.1016/j.cgh.2008.08.013.View ArticlePubMedGoogle Scholar
  28. Chow KM, Szeto CC: Impact of enforcing the Labour Ordinance, with 1-in-7-day off for hospital doctors, on weekend hospital discharge rate. J Public Health (Oxf). 2005, 27: 189-191. 10.1093/pubmed/fdi022.View ArticleGoogle Scholar
  29. Saposnik G, Baibergenova A, Bayer N, Hachinski V: Weekends: a dangerous time for having a stroke?. Stroke. 2007, 38: 1211-1215. 10.1161/01.STR.0000259622.78616.ea.View ArticlePubMedGoogle Scholar
  30. Bell CM, Redelmeier DA: Mortality among patients admitted to hospitals on weekends as compared with weekdays. N Engl J Med. 2001, 345: 663-668. 10.1056/NEJMsa003376.View ArticlePubMedGoogle Scholar

Copyright

© Novamedia srl 2011