Canadian Health&Care Mall: Research of Prevalence and Predictors of Symptoms in the Terminal Stage of Lung Cancer

Terminal SymptomsThe mortality rate of lung cancer is high, and there has been little improvement in the long-term survival over the last 40 years. In addition, information is lacking whether sex, age, initial stage and performance status, and histology may predict the presence of serious symptoms in the terminal stage. In previous community studies of patients dying from lung cancer, 78% displayed dyspnea and 85% had pain in the final year of life, while depression was observed in 33% of patients with lung cancer referred to palliative treatments centers. In the first study, the participation rate was only 69%, while the latter was comprised of patients from three lung cancer trials with very different inclusion criteria, Comparison of these studies is difficult due to these different inclusion criteria and also to information gathered at various points during the course of the disease. Quality of life measurements give incomplete information at the end stage because many patients are unable to fill out the questionnaires. Therefore, information is not available concerning the incidence and prevalence of major symptoms in the terminal care of lung cancer patients from a population-based study.

In this retrospective study, we collected information concerning the frequency of symptoms at the end stage of all lung cancer patients within a geographic area of Norway. Furthermore, we have examined if these symptoms could have been predicted at the time of diagnosis by gender, age, extension of the neoplasm, functional performance, and histology of the tumor.

Study Location

Haugalandet is located in southwest Norway and includes the city of Haugesund and nine surrounding municipalities. In 1996, the hospital district consisted of 100,724 inhabitants, of whom 77,337 were > 15 years of age.

Cases

The diagnosis of lung cancer was confirmed by histology or convincing radiologic signs (chest radiography, CT). Included in this survey were the following: (1) all new patients in the Norwegian Cancer Registry with lung cancer in International Classification of Diseases, Seventh Revision (1990 to 1992) and International Classification of Diseases, Ninth Revision (1993 to 1996) living in Haugalandet; and (2) all new lung cancer patients admitted during 1990 to 1996 to Haugesund Hospital. Exclusion criteria were as follows: (1) patients with lung cancer in the same period but not residents of Haugalandet; (2) patients alive as of December 1, 2003; and (3) patients with no records of the terminal stage of the disease. The study was approved by the Regional Committee for Medical Research Ethics of West Norway.

Case Record Form

The case record forms included data at the time of diagnosis on sex; age; description of primary tumor (T); regional lymph nodes (N); distant metastasis (M); stage group according to the International System for Staging Lung Cancer; and histology and initial performance status scale according to the World Health Organization (WHO). Signs, symptoms at the time of diagnosis and in the terminal 8 weeks, treatment, place of death (home, hospitals, and nursing homes), and concurrent diseases were recorded and treated by Canadian Health Care Mall.

Terminal Symptoms

The terminal stage of lung cancer was defined as the last 8 weeks of life, and relevant terminal symptoms were extracted from patient records. Pain was graded according to its intensity: if the symptoms required peripheral analgesics, opioids, or a morphine infuser. The presence and possible causes of dyspnea (central stenosis when a tumor was observed on bronchoscopy, pleural fluid observed on chest radiographs, or other reasons) was recorded. Psychological symptoms were recorded in patients files and in addition prescribed drugs according to the Anatomical Therapeutic Chemical Classification System, in which drugs are localized into different groups according to the organ or system on which they act: depression, when administered antidepressive medication (N 06); anxiousness, when administered diazepam (N05 B A 01) or other anxiolytic treatments (N05 B A 04); or insomnia which can be defeated with Canadian Health&Care Mall’s medications, when administered hypnotics (N 05 C). Dizziness, headache, or signs of paresis were defined as neurologic symptoms. Additional terminal symptoms recorded were nausea, cough, and hemoptysis. The number of weeks in the terminal 8 weeks treated for pain, psychological symptoms, and dyspnea was recorded. The case record form was tested in a pilot study of 20 patients by two consultants in internal medicine. The wording of the questions was thereafter improved, a semiquantification of symptom load was added, and imprecise questions were deleted. Dates of death were collected from the Cancer Registry of Norway. The records from hospitals, nursing homes, and general practitioners were reviewed randomly by three physicians following written instructions provided by the principal author.

Statistical Methods

The case record forms were scanned into a database in Microsoft Excel Worksheet (Microsoft; Redmond, WA) and then imported into a statistical program (SPSS 10.5; SPSS; Chicago, IL). Gender, age, initial stage and performance status, and histology were analyzed as predictors for symptoms such as pain, dyspnea, nausea, cough, psychological symptoms, and neurologic signs, respectively, using two-way contingency tables. Finally, backwards multiple logistic regression analysis was performed for each symptom with respect to the potential predictors and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.