The validity of rheumatoid arthritis diagnoses in Finnish biobanks.

OBJECTIVE: The aim of this study was to determine the validity of rheumatoid arthritis (RA) diagnoses in patients participating in Finnish biobanks. METHOD: We reviewed the electronic medical records of 500 Finnish biobank participants: 125 patients with at least one visit with a diagnosis of seropositive RA, 125 patients with at least one visit with a diagnosis of seronegative RA, and 250 age- and gender-matched controls. The patients were chosen from five different biobank hospitals in Finland. A rheumatologist reviewed the medical records to assess whether each patients' diagnosis was correct. The diagnosis was compared with the diagnostic codes in the Finnish Care Register for Health Care (CRHC) and special reimbursement data of the Social Insurance Institution of Finland. RESULTS: The positive predictive value (PPV) of CRHC diagnosis of RA (for seropositive and seronegative RA combined) was 0.82. For patients with a special reimbursement for anti-rheumatic medications for RA, the PPV was 0.89. The PPV was higher in patients with more than one visit. For one, two, five, and 10 visits, the PPV was 0.82, 0.85, 0.89, and 0.90, respectively, and for patients who also had the special reimbursement, the PPV was 0.89, 0.91, 0.93, and 0.94 for one, two, five, and 10 visits, respectively. In patients positive for anti-citrullinated protein antibodies, the PPV was 0.98. CONCLUSION: These results demonstrate that the validity of RA diagnoses in Finnish biobanks was good and can be further improved by including data on special reimbursement for medication, number of visits, and serological data.

Immunogenicity of subcutaneous TNF inhibitors and its clinical significance in real-life setting in patients with spondyloarthritis.

KEY MESSAGES: Considerable proportion of patients with SpA have been immunized to the subcutaneous anti-TNF drug they are using. Concomitant use of MTX protects from immunization, whereas SASP does not. Patients with SpA using subcutaneous anti-TNF drugs can benefit from monitoring of the drug trough levels. Immunization to biological drugs can lead to decreased efficacy and increased risk of adverse effects. The objective of this cross-sectional study was to assess the extent and significance of immunization to subcutaneous tumor necrosis factor (TNF) inhibitors in axial spondyloarthritis (axSpA) patients in real-life setting. A serum sample was taken 1-2 days before the next drug injection. Drug trough concentrations, anti-drug antibodies (ADAb) and TNF-blocking capacity were measured in 273 patients with axSpA using subcutaneous anti-TNF drugs. The clinical activity of SpA was assessed using the Bath AS Disease Activity Index (BASDAI) and the Maastricht AS Entheses Score (MASES). ADAb were found in 11% of the 273 patients: in 21/99 (21%) of patients who used adalimumab, in 0/83 (0%) of those who used etanercept, in 2/79 (3%) of those who used golimumab and in 6/12 (50%) of those who used certolizumab pegol. Use of methotrexate reduced the risk of formation of ADAb, whereas sulfasalazine did not. Presence of ADAb resulted in decreased drug concentration and reduced TNF-blocking capacity. However, low levels of ADAb had no effect on TNF-blocking capacity and did not correlate with disease activity. The drug trough levels were below the consensus target level in 36% of the patients. High BMI correlated with low drug trough concentration. Patients with low drug trough levels had higher disease activity. The presence of anti-drug antibodies was associated with reduced drug trough levels, and the patients with low drug trough levels had higher disease activity. The drug trough levels were below target level in significant proportion of patients and, thus, measuring the drug concentration and ADAb could help to optimize the treatment in SpA patients.

Antibodies to malondialdehyde-acetaldehyde modified low-density lipoprotein in patients with newly diagnosed inflammatory joint disease.

Objective:To assess antibodies to malondialdehyde-acetaldehyde-modified low-density lipoprotein (MAA-LDL) in patients with newly diagnosed inflammatory joint disease.Method: Patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), and undifferentiated arthritis (UA), participating in the Northern Savo 2010 Study, were evaluated for metabolic syndrome (MetS), metabolic and inflammatory markers, antibodies to MAA-LDL, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis.Results: Among 135 newly diagnosed untreated patients, of whom 53 (39%) were diagnosed to have RA, 44 (33%) SpA, and 38 (28%) UA, 49%, 30%, and 47%, respectively, had MetS. After adjusting for age and gender, anti-MAA-LDL immunoglobulin (Ig)A (p = 0.009), IgG (p = 0.031), and IgM (p = 0.001) levels differed between the diagnostic categories, but not in patients with MetS present or absent. All antibody classes to MAA-LDL correlated with erythrocyte sedimentation rate (ESR), and IgA and IgG antibodies with high-sensitivity C-reactive protein (hs-CRP). IgA antibodies to MAA-LDL correlated with rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPAs), fasting plasma glucose, IgA antibodies to A. actinomycetemcomitans, and in IgA and IgG antibodies to P. gingivalis.Conclusion: Among various arthritis groups, antibodies to MAA-LDL were most common in RA. Antibodies to modified lipoproteins were associated with inflammation measured by ESR and hs-CRP. IgA antibodies to MAA-LDL correlated with age, antibodies to periodontal bacteria, RF, ACPA, and fasting glucose. Associations between antibodies to MAA-LDL and antibodies to periodontal bacteria, RA-associated antibodies, inflammatory parameters, and plasma glucose already reflect cardiovascular burden in inflammatory joint diseases at diagnosis.

Incidence of inflammatory joint diseases in Finland: results from a population-based epidemiological study.

The objective of the study was to assess the incidence of inflammatory joint diseases and possible environmental factors contributing to their occurrence in a defined population in Finland. All rheumatologists practising in the Northern Savo rheumatological outpatient departments collected data on their newly diagnosed patients with an inflammatory joint disease in 2010. Antibodies to Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) were determined from patients with various arthritides. The incidence of all arthritis cases was 141.8/100,000 (95% CI 126.1-159.1). Eighty-six patients, 43 men and 43 women, satisfied the ACR/Eular 2010 classification criteria for rheumatoid arthritis (RA) yielding an annual incidence of 41.6/100,000 (33.3-51.4), 42.5 (30.8-57.3) for men and 40.8 (29.9-56.1) for women. The incidence of chronic spondyloarthritides was 36.3 (28.6-45.5), reactive arthritis 7.8 (4.4-12.6), undifferentiated arthritis 38.7 (30.7-48.2), and crystalline arthritis 15.0 (10.2-21.3). Immunoglobulin A (IgA) antibody levels to Pg were higher among men, patients with anti-cyclic citrullinated peptide antibodies (ACPA) or missing teeth and AaIgA antibody levels in patients with missing teeth. In RA, 67 % of men and 35% of women had a smoking history, p = 0.012. There was no difference between the genders in the incidence of RA, which might be explained by a higher carriage of periodontal bacteria and a higher smoking rate among men. In other disease categories, the incidences were comparable to those earlier reported. By influencing behavioral and environmental factors, it might be possible to reduce the burden of ACPA-positive RA.

Estimating the incidence of connective tissue diseases and vasculitides in a defined population in Northern Savo area in 2010.

Objective of the study was to evaluate the annual incidence and distribution of autoimmune connective tissue diseases and vasculitides during 2010. All units practicing rheumatology in the Northern Savo area, Finland, participated in the study by collecting data on newly diagnosed adult patients with autoimmune connective tissue disease or vasculitis over 1-year period. Seventy-two cases with autoimmune connective tissue disease were identified. The annual incidence rates were as follows: systemic lupus erythematosus 3.4/100,000 (95 % CI 1.4-7.0), idiopathic inflammatory myopathies 1.9 (0.5-5.0), systemic sclerosis 4.4 (2.0-8.3), mixed connective tissue disease 1.0 (0.1-3.5), Sjögren's syndrome 10.7 (6.7-16.1) and undifferentiated connective tissue disease 13.6 (9.0-19.6). The annual incidence rates among vasculitis category were as follows: antineutrophil cytoplasmic antibody-associated vasculitis 1.5/100,000 (95 % CI 0.3-4.3), central nervous system vasculitis 0.5 (0-2.7) and Henoch-Schönlein purpura 1.5 (0.3-4.3). The annual incidence of giant cell arteritis in the age group of 50 years or older was 7.5/100,000 (95 % CI 3.2-14.8). The longest delay from symptom onset to diagnosis occurred in systemic sclerosis. The incidences of autoimmune connective tissue diseases and vasculitides were comparable with those in published literature. The present study showed female predominance in all connective tissue diseases, excluding idiopathic inflammatory muscle diseases and mean age at onset of disease around 50 years of age. Despite improved diagnostic tools, diagnostic delay is long especially among patients with systemic sclerosis.

Drugs used in incident systemic lupus erythematosus - results from the Finnish nationwide register 2000-2007.

The objectives of the study were to examine the initial, first-year anti-rheumatic outpatient therapy in patients with incident SLE, as well as the concomitant use of drugs for certain comorbidities, compared to the use in the general population. The Finnish nationwide register data on special reimbursements for medication costs was screened to identify the inception cohort of 566 adult SLE patients (87% females, mean age 46.5 ± 15.9 years) over the years 2000-2007. The patients were linked to the national Drug Purchase Register. Of those, 90% had purchased at least once some disease-modifying anti-rheumatic drugs (DMARDs) during the first year. Hydroxychloroquine was the most common (76%), followed by azathioprine (15%) and methotrexate (13%). With the exception of increase in mycophenolate mofetil, the proportions remained stable over the whole study period 2000-2007. Drugs for cardiovascular diseases, dyslipidemia, diabetes mellitus, hypothyroidism and obstructive pulmonary disease were more frequently purchased than in the sex- and age-adjusted population, with rate ratios ranging from 1.6 to 7.8. Over the years 2000-2007, almost all the patients with incident SLE in Finland started with a DMARD. Higher percentages of SLE patients were on medication for several common chronic diseases than in the population as a whole.

Impact of physicians' adherence to treat-to-target strategy on outcomes in early rheumatoid arthritis in the NEO-RACo trial.

OBJECTIVES: It is well recognized that medication adherence of rheumatoid arthritis (RA) patients is often poor. As less attention has been paid to physicians' adherence to targeted treatment, we aimed to investigate how it affects outcomes in aggressively treated early RA patients. METHOD: In the new Finnish RA Combination Therapy (NEO-RACo) trial, 99 patients with early active RA were treated, targeting remission, with a combination of methotrexate, sulfasalazine, hydroxychloroquine, and low-dose prednisolone for 2 years, and randomized to receive infliximab or placebo for the initial 6 months. After 2 years, therapy was unrestricted while remission was still targeted. Patients were divided into tertiles by physicians' adherence to treat-to-target, which was evaluated with a scoring system during the initial 2 years. After 5 years of follow-up, the between-tertile differences in remission rates, 28-joint Disease Activity Score (DAS28) levels, radiological changes, cumulative days off work, and the use of anti-rheumatic medication were assessed. RESULTS: Follow-up data were available for 93 patients. Physicians' good adherence was associated with improved remission rates at 2-4 years and lower DAS28 levels throughout the follow-up. In a multivariable model, physicians' adherence was the most important predictor of remission at 3 months and 2 years (p < 0.001 for both). Between 2 and 5 years, biologics were used more often in the tertile of low adherence compared with the other two groups (p = 0.024). No significant differences were observed in radiological progression and cumulative days off work. CONCLUSIONS: Physicians' good adherence is associated with improved remission rates and lesser use of biologics in early RA.

Mortality and causes of death among incident cases of systemic lupus erythematosus in Finland 2000-2008.

The objectives of the study were to investigate mortality and causes of death in patients with recent-onset systemic lupus erythematosus (SLE) in Finland. Data for patients with SLE for the study were collected (2000-2007) from the nationwide register on decisions of special reimbursements for drugs, maintained by the Social Insurance Institution (SII) in Finland. Data on deaths of the patients were obtained from the official death certificate statistics of Statistics Finland until the end of 2008. Of the 566 incident SLE patients, median follow-up time was 5.4 (IQR 3.3, 7.1) years, and 30 patients (23 females, seven males) died in the years 2000 through 2008. Mean age at death was 67.8 ± 17.2 years for females and 62.3 ± 15.2 years for males. The 5-year survival rates were 94.8% (95%CI 92.0-96.6%) and 88.2% (95%CI 76.5-94.3%), respectively. The age- and sex-adjusted standardized mortality ratio was 1.48 (95%CI 1.01-2.12). Primary causes of death were cardiovascular diseases, malignancy and SLE itself. In conclusion, survival of the patients with SLE was inferior to that of the general population. Cardiovascular diseases were responsible for 37% of deaths.

Renal safety of initial combination versus single DMARD therapy in patients with early rheumatoid arthritis: an 11-year experience from the FIN-RACo Trial.

OBJECTIVE: To evaluate the renal safety of traditional disease-modifying antirheumatic drugs (DMARDs) in early rheumatoid arthritis (RA). METHODS: One hundred and ninety-five DMARD-naïve patients with recent-onset RA were randomised to receive combination DMARD therapy (n=97) starting with sulfasalazine, methotrexate, hydroxychloroquine, and prednisolone (COMBI) or monotherapy (n=98), initially with sulfasalazine, with or without prednisolone (SINGLE). After two years, the choice and dosing of DMARDs and prednisolone were not restricted, but the treatment was still targeted to achieve or maintain remission. Urinalysis, serum creatinine and glomerular filtration rate (GFR; estimated according to the Cockcroft-Gault formula [eGFRCG]) were analysed at baseline and at months 6, 9, 12, 18, 24 and thereafter yearly up to 11 years. RESULTS: The cumulative incidence of repeated (>or=3 times) abnormal renal findings during the 11-year follow-up period were as follows (COMBI versus SINGLE; p-values adjusted for age and sex): proteinuria (dipstick positive) 4.8% (95%CI 1.8-12.2) vs. 5.3% (95%CI 2.0-13.7, p=0.93), haematuria (dipstick positive) 14.1% (95%CI 8.0-24.2) vs. 22.1 % (95%CI 14.5-33.0, p=0.14), raised serum creatinine (>or=100 micromol/l in females and >or=115 micromol/l in males) 4.4% (95%CI 1.7-11.4) vs. 6.7% (3.0-14.3, p=0.87) and eGFRGC<60 ml/min/1.73 m2 11.9% (95%CI 6.8-20.5) vs. 10.5% (95%CI 5.8-18.7, p=0.85). CONCLUSION: Initial remission targeted therapy with the FIN-RACo DMARD combination in early RA is safe for kidneys and does not induce more short- or long-term renal complications compared to traditional therapy with a single DMARD.

Prevalence of antibodies against Chlamydia trachomatis and incidence of C. trachomatis-induced reactive arthritis in an early arthritis series in Finland in 2000.

OBJECTIVE: To study the prevalence of different serotypes of Chlamydia trachomatis antibodies and the incidence of C. trachomatis-induced reactive arthritis (ReA) among patients with early arthritis in a defined population. METHODS: Serum samples were collected from a cohort of 122 adult patients in the age group 18-65 years included in the Kuopio 2000 Arthritis Survey. Antibodies against C. trachomatis serotypes C, E, and G were studied using enzyme immunoassay (EIA) tests among patients and in a control cohort of 78 adults without any joint symptoms. The incidence assessment for Chlamydia-induced ReA was based on a ligase chain reaction (LCR) test in urine and clinical symptoms and signs appropriate for ReA. RESULTS: Of 122 patients, with the baseline diagnosis of rheumatoid arthritis (RA) in 11, spondyloarthropathy (SpA) in 28, and undifferentiated arthritis (UA) in 83 cases, 42 (34%) showed immunoglobulin (Ig)G or IgA antibodies against at least one serotype C, E, or G. Among the patients with UA the prevalence was significantly increased compared with the controls (p = 0.010). C. trachomatis-induced ReA arthritis was diagnosed in only three patients with the LCR test. On this basis the incidence of C. trachomatis-induced arthritis was 5.4/100 000 [95% confidence interval (CI) 1.1-15.7] in the age group 18-65 years. CONCLUSION: Antibodies against C. trachomatis were most common in patients with UA reflecting the fact that cases with chlamydia-induced ReA are included in this subgroup.

Serum soluble CD30 in early arthritis: a sign of inflammation but not a predictor of outcome.

OBJECTIVE: To evaluate serum soluble CD30 levels (sCD30) in an early arthritis series and assess their ability to predict the outcome in patients with rheumatoid arthritis (RA) and undifferentiated arthritis (UA) at one year follow-up. METHODS: Serum sCD30 levels were measured by ELISA from 92 adult patients with RA and UA at baseline and from 60 adult controls. The patients were followed up for one year in the Kuopio 2000 Arthritis Survey. Receiver operating characteristic (ROC) curves were constructed to determine cut off points of sCD30 in RA and UA that select the inflammatory disease from controls. Sensitivity, specificity and positive likelihood ratio, and their 95 % CIs were calculated for sCD30 levels in RA and UA. RESULTS: Median serum sCD30 levels were higher in RA 25.1 (IQ range 16.3-38.6) IU/ml (p<0.001) and in UA 23.4 (15.4-35.6) IU/ml (p<0.001) than in controls 15.1 (10.7-20.8) IU/ml. No differences were recorded between RA and UA (p=0.840). Serum sCD30 levels at baseline did not predict remission at one year follow-up. CONCLUSION: Serum sCD30 levels were higher in RA and UA than in controls at baseline but they did not predict remission at one year follow-up in this series.

Risk factors in heating, ventilating, and air-conditioning systems for occupant symptoms in US office buildings: the US EPA BASE study.

UNLABELLED: Building-related symptoms in office workers worldwide are common, but of uncertain etiology. One cause may be contaminants related to characteristics of heating, ventilating, and air-conditioning (HVAC) systems. We analyzed data from 97 representative air-conditioned US office buildings in the Building Assessment and Survey Evaluation (BASE) study. Using logistic regression models with generalized estimating equations, we estimated odds ratios (OR) and 95% confidence intervals for associations between building-related symptom outcomes and HVAC characteristics. Outdoor air intakes less than 60 m above ground level were associated with significant increases in most symptoms: e.g. for upper respiratory symptoms, OR for intake heights 30 to 60 m, 0 to <30 m, and below ground level were 2.7, 2.0, and 2.1. Humidification systems with poor condition/maintenance were associated with significantly increased upper respiratory symptoms, eye symptoms, fatigue/difficulty concentrating, and skin symptoms, with OR = 1.5, 1.5, 1.7, and 1.6. Less frequent cleaning of cooling coils and drain pans was associated with significantly increased eye symptoms and headache, with OR = 1.7 and 1.6. Symptoms may be due to microbial exposures from poorly maintained ventilation systems and to greater levels of vehicular pollutants at air intakes nearer the ground level. Replication and explanation of these findings is needed. PRACTICAL IMPLICATIONS: These findings support current beliefs that moisture-related HVAC components such as cooling coils and humidification systems, when poorly maintained, may be sources of contaminants that cause adverse health effects in occupants, even if we cannot yet identify or measure the causal exposures. While finding substantially elevated risks for poorly maintained humidification systems, relative to no humidification systems, the findings do not identify important (symptom) benefits from well-maintained humidification systems. Findings also provide an initial suggestion, needing corroboration, that outdoor air intakes lower than 18 stories in office buildings may be associated with substantial increases in many symptoms. If this is corroborated and linked to ground-level vehicle emissions, urban ventilation air intakes may need to be located as far above ground level as possible or to incorporate air cleaners that remove gaseous pollutants.

Sensitivity and specificity of autoantibodies binding to citrullinated carboxyterminal telopeptides of types I and II collagens in an early arthritis series.

OBJECTIVE: To assess the specificity and sensitivity of autoantibodies binding to citrullinated carboxyterminal telopeptides of types I and II collagens in an early arthritis series. METHODS: A cohort of 146 patients from the Kuopio 2000 Arthritis Survey having RA, AS, PsA, ReA, uSpA or undifferentiated arthritis were studied. Autoantibodies binding citrullinated types I and II carboxytelopeptides were measured in two different inhibition ELISA assays. Sera from 135 adult persons were used as controls. RESULTS: In RA, the sensitivities were 0.83 with long type I telopeptide and 0.78 with long type II telopeptide and the respective specificities were 0.94 and 0.93, while the corresponding values in other inflammatory joint diseases were much lower. The likelihood ratio in RA increased with longer peptides from 4.20 to 14.06 for type I telopeptide and from 2.74 to 11.67 for type II telopeptide. CONCLUSION: The antibody assay using long telopeptide from type I collagen was the most specific and sensitive method in every diagnostic category, although in the arthritides other than RA, binding was much less abundant and possibly citrulline-independent.

Intensifying treatment of rheumatoid arthritis with combinations of traditional disease-modifying anti-rheumatic drugs among patients with persistent disease did not reduce the need for large joint surgery.

OBJECTIVE: To analyse how treatment of patients with rheumatoid arthritis (RA) influenced the duration of the disease before the first large joint surgery, arthrodesis or arthroplasty, in two patient cohorts 10 years apart. METHODS: Data on patients with RA having an arthrodesis or arthroplasty of a large joint from 1990 to 1992 and from 2000 to 2002 and the type of medication used among all patients with RA in 1988-2002 were extracted from the data set of Kuopio University Hospital. RESULTS: The median duration of the disease before the decision of arthrodesis was 6.0 (range 1-25) years in 1990-92 and 9.0 (1-31) years (p = 0.307) in 2000-02, and of arthroplasty 10.5 (0-27) and 12.5 (0-59) years (p = 0.820), respectively. A significant shift from only symptomatic treatment or one disease-modifying anti-rheumatic drug (DMARD) to the more common use of immunosuppressants and/or combinations of at least two DMARDs occurred between 1992 and 2002. CONCLUSIONS: Treatment of RA at diagnosis and during the first years after diagnosis was traditional. Intensifying treatment later in the disease course did not reduce the need for large joint surgery as it occurred in the same time range in both cohorts.

Change of diagnoses and outcome of patients with early inflammatory joint diseases during a mean 13-month follow-up.

OBJECTIVE: To assess the state of the disease and verify the diagnoses during a 7-24-month follow-up of adult patients with newly diagnosed inflammatory joint diseases in a defined population. METHODS: Patients with previously undiagnosed synovitis in at least one peripheral joint or signs of inflammation in sacroiliac, glenohumeral or hip joints were enrolled on their first hospital visit in 2000 and followed-up for up to 24 months in Kuopio. RESULTS: A total of 138/173 adult patients completed a mean 13-month follow-up. During the follow-up the diagnosis was specified for 15/81 (19%) patients previously classified as undifferentiated arthritis (UA). Eight patients developed rheumatoid arthritis (RA). Of 28 patients with RA, 92% were on disease-modifying anti-rheumatic drugs (DMARDs) and 75% had a combination treatment with two or more DMARDs. According to the diagnosis at baseline, 75% of cases with RA, 38% with spondyloarthropathies (SpAs) and 42% with UA had active synovitis or arthralgia at follow-up. In multivariate analysis, older patients at disease onset were less likely to be in remission (p = 0.011). CONCLUSION: The diagnosis could be specified for 19% of patients with UA. Fifteen of 20 patients with RA had an active disease despite treatment with DMARDs. Patients with SpAs and UA had a better short-term outcome. Patients with active disease need aggressive therapy in all age groups.

Potential effects of permeable and hygroscopic lightweight structures on thermal comfort and perceived IAQ in a cold climate.

UNLABELLED: In this study, we simulated and measured the effect of permeable and hygroscopic lightweight structures on indoor air quality (IAQ) and thermal comfort in a cold climate. The potential effect of hygroscopic mass was assessed with the simulation of extreme cases, where permeable and hygroscopic lightweight structures with unfinished surfaces were compared with impermeable and non-hygroscopic ones. Measurements were conducted in 78 rooms of 46 newly built detached timber-framed houses and analyzed according to hygroscopic surface materials and envelope permeability. From the simulations, it was shown that permeable and hygroscopic structures considerably improved perceived air quality in summer, when a ventilation rate of 6 l/s pers. in the non-hygroscopic case corresponded roughly to 4 l/s pers. in the hygroscopic case. However, window airing and furnishing will reduce this difference in practice. Both simulated and measured results showed that permeable and hygroscopic structures significantly reduced peak indoor relative humidity levels and daily changes in relative humidity, but had no long-term effects. Measured results also indicated that completely non-hygroscopic houses did not exist in reality. PRACTICAL IMPLICATIONS: Limited knowledge is available about building envelope and ventilation system interactions with consequent effects on indoor climate. To take such effects adequately into account in design and construction of buildings, solid scientific data explaining the significance of the phenomena studied are needed. We have demonstrated that moisture exchange has evidently enough importance to be taken into account in future building simulation tools.

Working towards healthy air in dwellings in Europe.

Poor indoor air quality has been implicated in the increase in allergic and respiratory diseases seen in industrialized countries in recent decades. Although air pollution in the workplace is well studied, much less is known about the consequences of poor air quality in homes. In an attempt to halt or slow down the increase in allergic and respiratory diseases, the European Federation of Allergy and Airways Diseases Patients Associations (EFA) carried out the EU-funded project entitled 'Towards Healthy Air in Dwellings in Europe' (THADE). The aims were to: compile an overview of evidence-based data about exposure to indoor air pollution and its health effects, particularly in relation to allergies, asthma and other respiratory diseases such as chronic obstructive pulmonary disease; review cost-effective measures and technology to improve indoor air quality; review legislation and guidelines on indoor air pollution; produce maps of pollutants in dwellings; and recommend an integrated strategy that defines appropriate indoor air quality policies for implementation in Europe. This paper summarizes the information about air quality in dwellings and indoor environment-related diseases collected by expert consultants within the framework of THADE and terminates with recommendations for actions aimed at improving air quality in homes. The results of this project confirmed that air pollution in dwellings is a relevant health problem. It is a complex problem that must be addressed at European and international levels, and it involves the medical profession, scientific societies, patients' organizations, lawmakers, architects and the building industry. The complete THADE report is available at http://www.efanet.org/activities/documents/THADEReport.pdf.

Ventilation and performance in office work.

Outdoor air ventilation rates vary considerably between and within buildings, and may be too low in some spaces. The purpose of this study was to evaluate the potential work performance benefits of increased ventilation. We analyzed the literature relating work performance with ventilation rate and employed statistical analyses with weighting factors to combine the results of different studies. The studies included in the review assessed performance of various tasks in laboratory experiments and measured performance at work in real buildings. Almost all studies found increases in performance with higher ventilation rates. The studies indicated typically a 1-3% improvement in average performance per 10 l/s-person increase in outdoor air ventilation rate. The performance increase per unit increase in ventilation was bigger with ventilation rates below 20 l/s-person and almost negligible with ventilation rates over 45 l/s-person. The performance increase was statistically significant with increased ventilation rates up to 15 l/s-person with 95% CI and up to 17 l/s-person with 90% CI. Practical Implications We have demonstrated a quantitative relationship between work performance and ventilation within a wide range of ventilation rates. The model shows a continuous increase in performance per unit increase in ventilation rate from 6.5 l/s-person to 65 l/s-person. The increase is statistically significant up to 15 l/s-person. This relationship has a high level of uncertainty; however, use of this relationship in ventilation design and feasibility studies may be preferable to the current practice, which ignores the relationship between ventilation and productivity.