Comorbidity among Danish lung cancer patients before and after initial cancer diagnosis

Abstract

Objective: Lung cancer is the leading cause of cancer-related death worldwide. This populationbased longitudinal study investigates survival rates and the burden of comorbidity before and after being diagnosed with lung cancer in Denmark. Methods: From the Danish National Patient Registry (NPR) and the Danish Civil Registration System (CPR), 53,749 patients with lung cancer were identified and matched with 214,304 controls on age, gender, region of residence and marital status in the period 1998-2010. From the NPR, data on survival and comorbidity, registered as ICD-10 diagnoses, were extracted. Comorbidity was assessed using the Deyo-Charlson comorbidity score (DCcs) and mortality using Kaplan-Meier survival curves. Results: 1-year survival rate for Danish lung cancer patients was 51.7 % (CI 51.3-52.1) and 5-year survival rate was 14.7 % (CI 14.3-15.0) compared to 96.8 % (CI 96.7-96.8) and 84.0 % (CI 83.9-84.2) for controls respectively. Overall, cases had significantly more comorbidity compared to controls before being diagnosed with lung cancer. Prior to being diagnosed with lung cancer, more cases than controls had been diagnosed with other malignancies (11.4 % vs 6.0 % p<0.005), diseases of the circulatory system (16.4 % vs 13.0 % p<0.005) and respiratory diseases (12.2 % vs 4.8 % p<0.005). Among lung cancer patients 21.8 % had a DCcs ≥ 1 compared to 13.3 % among controls (P<0.005). The 1-year survival for DCcs =0 was 54.8 % 3) for lung cancer patients and 97.8 % (CI 97.7-97.9) for controls. Decreasing survival with increasing DCcs was found in both groups. Conclusion:This study provides unique nationwide comorbidity data on patients before and after being diagnosed with lung cancer. We found increased mortality with increasing comorbidity, however more pronounced among controls compared to patients with lung cancer.

Direct and indirect economic burden of lung cancer in Denmark a nationwide study

“…More than 99% of the observations in the two groups were successfully matched. Age distribution, marital status, survival and comorbidity of lung cancer patients and matched controls have previously been published [ 13 ]. Lung cancer was associated with significantly higher rates of health care related costs, medication use and lower income rates compared to the matched control group before and increasingly so after being diagnosed with lung cancer ( Table 1 ).…”

“…Public funded sick pay was substantially higher for lung cancer patients compared to controls even before, but increasingly so after diagnosis. This corresponds to lung cancer patients higher burden of comorbidity [13,19,20]. Few studies have included indirect costs in economic evaluations of lung cancer.…”