On the crest of a wave: Danish prevalence of hospitalisation-required COPD 2002-2009

Trends in assisted ventilation and outcome for obstructive pulmonary disease exacerbations. A nationwide study

BACKGROUND

Non-invasive ventilation (NIV) has been used for decades in treatment of exacerbations of chronic obstructive pulmonary disease (COPD). The impact of the changing use of assisted ventilation in acute exacerbations on outcomes has not been fully elucidated and we aimed to describe these changes in the Danish population and describe their consequences for mortality.

METHODS

A register-based study was conducted of a cohort of 12,847 patients admitted for acute exacerbation of COPD (AECOPD) from 2004 through 2011, treated with invasive mechanical ventilation (IMV) or NIV for the first time. Age, sex, in-hospital mortality rates, time to death or readmission for AECOPD were established and changes over time tracked.

RESULTS

The number of admissions for AECOPD where assisted ventilation was used was 1,130 in 2004 and had increased by 145% in 2011. First time ventilations increased by 88%. This was mainly due to an increase in use of NIV accounting for 36% of the total number of assisted ventilations in 2004 and 67% in 2011. The number of IMV with or without NIV treatments remained constant. The mean age of NIV patients increased from 71.5 to 73.6 years, but remained constant at 70.0 years in IMV patients. Mortality rates both in hospital and after discharge for patients receiving NIV remained constant throughout the period. In-hospital mortality following IMV increased from 30% to 38%, but mortality after discharge remained stable.

CONCLUSION

Assisted ventilation has been increasingly used in a broader spectrum of AECOPD patients since the introduction of NIV. The changes in treatment strategies have been followed by shifts in in-hospital mortality rates following IMV.

Chronic obstructive pulmonary disease in Denmark: Age-period-cohort analysis of first-time hospitalisations and deaths 1994-2012

BACKGROUND

During the 80s and 90s the mortality and number of hospitalisations due to chronic obstructive pulmonary disease (COPD) in the country of Denmark almost doubled. Since then there has been a plateau.

OBJECTIVE

To analyse age, period, and cohort effects on rates of deaths and first-time hospitalisations with COPD in Denmark during the period from 1994 to 2012 and to make a forecast of these parameters.

METHODS

By use of national registers, two separate age-period-cohort analyses were made, one on COPD-specific mortality rates and the other on incidence rates of first-time hospitalisations with COPD.

RESULTS

Both analyses found that high risk of developing severe COPD is associated with being born for women around year 1930 and for men around year 1925. The model has solid predictive ability and projections of future death- and hospitalisation rates due to COPD were made.

CONCLUSION

Long-term cohort effects rather than present exposure and treatment explain the recent rise and fall in the epidemic of COPD in Denmark. In the near future ageing of birth cohorts with lower COPD-specific mortality and hospitalisation rates will most likely lead to a substantial decrease in severe COPD in Denmark. However, rising trends for cohorts born after year 1948 calls for concern.

Trends in long-term oxygen therapy for COPD in Denmark from 2001 to 2010

OBJECTIVES

To evaluate changes in demographics, incidence, prevalence, treatment modalities, and survival of COPD patients on long-term oxygen therapy (LTOT) from year 2001-2010 in Denmark.

METHODS

All 14,965 COPD patients with COPD treated LTOT in Denmark in the period 2001-2010.

RESULTS

During the study period, the incidence and prevalence of COPD patients on LTOT increased from 30.5 to 32.2 per 100.000, and from 42.0 to 48.1 per 100.000, respectively. Mean age of patients increased from 73.4 to 74.8 years, P < 0.001. An increasing number of patients were prescribed LTOT in connection with discharge after hospitalisation for an exacerbation (2001 vs. 2010: 76.5% vs. 91.7%, P < 0.001); were prescribed oxygen 15-24 h/day (85.8% vs. 89.5%, P < 0.001); had mobile oxygen (56.4% vs. 94.2%, P < 0.001), and stopped LTOT alive within 6 months (20.6% vs. 30.8%, P < 0.001). Ninety-nine percent of the patients received oxygen concentrator or liquid oxygen with no change in the study period (P = 0.66). The median survival on LTOT increased insignificantly from 16.5 to 17.8 months (P = 0.12). Women had a lower risk of dying compared with men, with an adjusted hazard ratio of 0.81 (95% confidence interval (CI) 0.78-0.84), P < 0.001). During the study period, the risk of death for women, compared to men, decreased significantly with a hazard ratio of 0.978 (95% CI: 0.964-0.992) per calendar year.

CONCLUSIONS

The incidence of COPD patients on LTOT in Denmark has levelled of during recent years, and the quality of prescribing LTOT and follow up has improved. Women had better survival than men, and this difference has increased during the study period.