Reference values of spirometry for Finnish adults.

BACKGROUND: Diagnostic assessment of lung function necessitates up-to-date reference values. The aim of this study was to estimate reference values for spirometry for the Finnish population between 18 and 80 years and to compare them with the existing Finnish, European and the recently published global GLI2012 reference values. METHODS: Spirometry was performed for 1380 adults in the population-based FinEsS studies and for 662 healthy non-smoking volunteer adults. Detailed predefined questionnaire screening of diseases and symptoms, and quality control of spirometry yielded a sample of 1000 native Finns (387 men) healthy non-smokers aged 18-83 years. Sex-specific reference values, which are estimated using the GAMLSS method and adjusted for age and height, are provided. RESULTS: The predicted values for lung volumes are larger than those obtained by GLI2012 prediction for the Caucasian subgroup for forced vital capacity (FVC) by an average 6·2% and 5·1% and forced expiratory volume in 1 s (FEV1) by an average 4·2% and 3·0% in men and women, respectively. GLI2012 slightly overestimated the ratio FEV1/FVC with an age-dependent trend. Most reference equations from other European countries, with the exception of the Swiss SAPALDIA study, showed an underestimation of FVC and FEV1 to varying degrees, and a slight overestimation of FEV1/FVC. CONCLUSION: This study offers up-to-date reference values of spirometry for native Finns with a wide age range. The GLI2012 predictions seem not to be suitable for clinical use for native Finns due to underestimation of lung volumes.

Smoking, respiratory symptoms, and diseases : a comparative study between northern Sweden and northern Finland: report from the FinEsS study.

STUDY OBJECTIVES: The influences of different smoking categories on the prevalence of respiratory symptoms, asthma, and chronic bronchitis have been examined in the most northern province of Sweden, Norrbotten, and in Lapland, Finland. The two areas have similar geographic and demographic conditions. METHODS AND STUDY POPULATION: The study is a part of the FinEsS studies, which are epidemiologic respiratory surveys in progress in Sweden, Finland, and Estonia. A random sample of 20- to 69-years-olds were invited to answer a postal questionnaire about respiratory symptoms, smoking habits, and occupation. In Norrbotten, 8,333 subjects were invited and 7,104 responded (85%). In Lapland, 8,005 were invited and 6,633 responded (83%). RESULTS: The participation by age and sex was similar in both countries. The prevalence of smokers in Lapland was 32% vs 26% in Norrbotten. Significantly more women than men in Norrbotten were smokers, while the opposite was true for Lapland. Sputum production was the most prevalent symptom in both areas, 25% in Lapland vs 19% in Norrbotten. The prevalence of chronic productive cough was 11% in Lapland and 7% in Norrbotten. Bronchitic symptoms were more prevalent in Lapland among both smokers and nonsmokers. A positive family history of chronic obstructive airway disease together with increased number of consumed cigarettes showed an additive effect for both chronic productive cough and wheezing. The odds ratio (OR) for wheezing during the last 12 months was 3.8 for subjects without a family history of obstructive airway disease who consumed > 14 cigarettes per day compared with nonsmokers, but if the subjects had a family history of obstructive airway disease, the risk for wheezing increased to OR 8.4. CONCLUSION: Bronchitic symptoms were more common in Finland. The difference remained also after correction for demographic variables including smoking habits, age and socioeconomic group, and family history of obstructive airway disease. Identical methods, sample composition, and the high participation rate contribute to the validity of the results. Air pollution, including environmental tobacco smoke, may contribute to the difference. To explain the difference, further analysis and investigations of social and environmental factors as well as genetic factors are needed.

Increase of asthma in adults in northern Finland?--a report from the FinEsS study.

BACKGROUND: According to previous studies, the prevalence of asthma has been lower in Finland than in other Nordic countries. In the present study, we assessed the prevalence of asthma and respiratory symptoms in northern Finland and calculated risk factors for these conditions. METHODS: In November 1995, 7937 randomly selected subjects, 20-69 years of age, in northern Finland were invited to participate in a postal questionnaire survey. Complete answers were received from 6633 subjects (83.6%). RESULTS: Asthma diagnosed by a physician was reported by 6.0%, while 6.3% were using asthma medicines. Asthma was most common in young adults and the elderly. The prevalence of wheezing during the previous 12 months was reported by 19.7%, while wheezing with shortness of breath apart form colds during the previous 12 months was reported by 7.1%. Only small differences between the sexes were found in prevalence of asthma and respiratory symptoms. All symptoms were strongly smoking-dependent. Sixty-three percent of men and 42% of women were current or ex-smokers. Family history of obstructive airway disease was the strongest risk factor for asthma (OR 2.9), while increasing age, smoking, and family history of obstructive airway disease were the most important risk factors for frequent wheeze. CONCLUSIONS: The results indicate that the prevalence of asthma and symptoms associated with asthma in adults in northern Finland is now similar to that observed in Sweden and the other Nordic countries.

Does non-responder bias have a significant effect on the results in a postal questionnaire study?

BACKGROUND AND AIM: In epidemiological questionnaire studies results can be influenced by non-responder bias. However, in respiratory epidemiology this has been analysed in very few recently published papers. The aim of our paper is to assess if the results found in our previous postal questionnaire study in an adult population in Northern Finland were biased by non-response. METHODS: A random sample of 385 persons from the 1,284 non-responders in a previous postal questionnaire study was examined. The same questionnaire as in the original study was again mailed to these persons, and those still not answering were contacted by phone. RESULTS: Totally 183 complete answers (48%) were collected. Lack of interest (56%) and forgetting to mail the response letter (22%) were the most common reasons to non-response. Typical non-responders were young men and current smokers who less frequently reported respiratory symptoms in exercise and asthma than the responders in the original study. Answers collected by phone gave for some questions higher prevalence rates than postal answers. CONCLUSION: Firstly, in this population the response rate (83.6%) in the original study was high enough to provide reliable results for respiratory symptoms and diseases, only the prevalence of current smoking was biased by non-response. Secondly, the methods used for collecting responses in a non-response study may influence the results.

Dependence of cold-related coronary and respiratory symptoms on age and exposure to cold.

Cold causes cardiopulmonary stress often perceived as shortness of breath or chest pain, and causes exacerbation of these symptoms in persons suffering heart or lung disease. We investigated the prevalence of these symptoms and their association with sex, age and cold exposure in a population-based sample of 1,785 persons who lived in three areas of Finland. The exposure to cold was measured by the annual number cold days (mean daily temperature below 0 degree C) in the resident locality and weekly hours spent in the cold in winter. Shortness of breath was 25% and chest pain 52% more common in females than in males, and their prevalence increased by 24% and 77%, respectively, for every 10 years of age. The prevalence of shortness of breath increased by 5% and chest pain by 6% for every 10 cold days in the resident locality, and by 6% and 7% for every 10 hours spent in the cold, respectively. We suggest that environmental cold, measured by the number of cold days throughout the year and weekly hours spent in the cold, may provoke cardiopulmonary symptoms independent of sex and age.

Increasing prevalence of asthma but not of chronic bronchitis in Finland? Report from the FinEsS-Helsinki Study.

To assess the prevalence of asthma, chronic bronchitis and respiratory symptoms, and to calculate risk factors for them, we performed a postal survey in Helsinki, the capital of Finland. During the spring of 1996, questionnaires were mailed to a random sample of 8000 individuals aged 20-69. The total response rate was 76%, with 6062 complete answers. The prevalence of having ever had asthma was 7.2%, physician-diagnosed asthma was 6.6% and physician-diagnosed chronic bronchitis was 3.7%. Asthma was significantly more common among women than men, but no gender differences existed in prevalence of chronic bronchitis. The most common respiratory symptom was sputum production when coughing, reported by 27%. During the previous 12 months, wheezing had occurred in 20% and attacks of shortness of breath in 13% of subjects. Generally, the prevalence of different respiratory symptoms were significantly higher among smokers. The most important risk factor for asthma was a family history of asthma (Odds ratio:OR 3.3). Multivariate analysis revealed that being a member of the socioeconomic group, manual workers, was associated with a significantly increased risk for chronic productive cough (OR 1.7), and for wheezing during the previous 12 months (OR 1.7). Manual workers of both genders had the highest prevalence of asthma, chronic productive cough and wheezing during the previous 12 months. The prevalence of asthma in Helsinki was higher than previously found in Finland, and was at a similar level to that of other Nordic countries. In contrast, prevalence of chronic bronchitis was lower than previously shown in Finland.

Comparison of terbutaline Turbuhaler and albuterol chlorofluorocarbon (CFC) inhaler in middle-aged and elderly patients with obstructive lung disease.

The aim of the present study was to compare the effect of terbutaline Turbuhaler (0.5 mg qid) with that of albuterol chlorofluorocarbon (CFC) inhaler (0.2 mg qid) in middle-aged and elderly patients with obstructive lung disease. The study was performed as an open cross-over (2 x 2 weeks) and randomized study in 85 patients. A significant increase in PEF was seen after inhalation from both devices (P less than .001). Baseline PEF values before inhalation were higher with Turbuhaler than with the CFC inhaler both in the mornings and in the evenings. Fifty-six percent of the patients preferred terbutaline Turbuhaler and 26% albuterol CFC inhaler (P = .004).

Inhaled bronchodilator's in asthma: low or high dose?

We studied the effect of regular inhalations of low-dose and high-dose fenoterol and low-dose and high-dose combinations of fenoterol and ipratropium bromide in maintenance treatment of 120 adults with moderately severe asthma. We used a double-blind, randomized, parallel group design comparing 12 weeks of treatment with four regimens: fenoterol, 100 micrograms/dose; fenoterol, 200 micrograms/dose; fenoterol, 50 micrograms; and ipratropium, 20 micrograms/dose in a single inhaler (Berodual) and fenoterol, 100 micrograms and ipratropium, 40 micrograms/dose in a single inhaler (Duovent). During the baseline and active treatment period the patients recorded PEFR in the morning and evening, symptoms and use of a rescue inhaler. Changes in twice daily peak expiratory flow rates or asthma symptoms did not show any significant differences among the four treatment regimens during the 12 weeks compared with the baseline period. Use of the rescue inhaler did not differ among the four groups during the active treatment. The patients' assessment of the efficacy of the active treatment favored the low-dose fenoterol and low-dose combination. More side effects were recorded in the high-dose combination group during the first 4 weeks compared with the other groups. We conclude that in maintenance therapy of chronic asthma high doses of fenoterol alone or in combination with ipratropium bromide offer no clinical advantage over low doses. On the contrary, the low-dose fenoterol and the low-dose combination are better accepted and tolerated by the patients.