RESUMEN
No large study has described the seasonal variation in asthma attacks in population-based asthmatics in whom sensitisation to allergen has been measured. 2,637 young adults with asthma living in 15 countries reported the months in which they usually had attacks of asthma and had skin-prick tests performed. Differences in seasonal patterns by sensitisation status were assessed using generalised estimating equations. Most young adults with asthma reported periods of the year when their asthma attacks were more common (range: 47% in Sweden to 86% in Spain). Seasonal variation in asthma was not modified by sensitisation to house dust mite or cat allergens. Asthmatics sensitised to grass, birch and Alternaria allergens had different seasonal patterns to those not sensitised to each allergen, with some geographical variation. In southern Europe, those sensitised to grass allergens were more likely to report attacks occurred in spring or summer than in winter (OR March/April 2.60, 95% CI 1.70-3.97; OR May/June 4.43, 95% CI 2.34-8.39) and smaller later peaks were observed in northern Europe (OR May/June 1.25, 95% CI 0.60-2.64; OR July/August 1.66, 95% CI 0.89-3.10). Asthmatics reporting hay fever but who were not sensitised to grass showed no seasonal variations. Seasonal variations in asthma attacks in young adults are common and are different depending on sensitisation to outdoor, but not indoor, allergens.
Asunto(s)
Asma/etiología , Asma/inmunología , Hongos/inmunología , Polen/inmunología , Adulto , Alérgenos/inmunología , Alternaria/inmunología , Betula/inmunología , Europa (Continente) , Femenino , Estudios de Seguimiento , Humanos , Inmunoglobulina E/inmunología , Masculino , Oportunidad Relativa , Poaceae/inmunología , Distribución Aleatoria , Rinitis Alérgica Estacional/inmunología , Riesgo , Estaciones del Año , Pruebas Cutáneas , Encuestas y Cuestionarios , Adulto JovenRESUMEN
BACKGROUND: The tuberculin skin test (TST) is often used to screen for latent tuberculosis infection (LTBI) in school children, many of whom were bacille Calmette-Guérin (BCG)-vaccinated in infancy. The reliability of the TST in such children is unknown. METHODS: TSTs performed in low-risk BCG-vaccinated and -nonvaccinated grade 1 and grade 6 First Nations (North American Indian) school children in the province of Alberta, Canada, were evaluated retrospectively. To further assess the specificity of the TST, BCG-vaccinated children with a positive TST (≥10 mm of induration) and no treatment of LTBI were administered a QuantiFERON-TB Gold In-Tube test (QFT-GIT, Cellestis International). RESULTS: A total of 3996 children, 2063 (51.6%) BCG-vaccinated and 1933 (48.4%) BCG-nonvaccinated, were screened for LTBI. Vaccinated children were more likely than nonvaccinated children to be TST positive (5.7% vs. 0.2%, P < 0.001). Vaccinated children with a positive TST were more likely to have a recent past TST as compared with those with a negative TST (6.8% versus 2.8%, P = 0.01). Among 65 BCG-vaccinated TST-positive children who underwent a QFT-GIT, only 5 (7.7%; 95% CI: 2.5%, 17.0%) were QFT-GIT positive. A TST of ≥15 mm was more likely to be associated with a positive QFT-GIT than a TST of 10 to 14 mm, 16.0% (95% CI: 4.5%, 36.1%) versus 2.5% (95% CI: 0.1%, 13.2%), P = 0.047. CONCLUSION: The TST is unreliable in school children, BCG-vaccinated in infancy, and who are at low risk of infection. The QFT-GIT is a useful confirmatory test for LTBI in BCG-vaccinated TST-positive school children.
Asunto(s)
Vacuna BCG , Prueba de Tuberculina , Tuberculosis/prevención & control , Adolescente , Vacuna BCG/inmunología , Niño , Preescolar , Femenino , Humanos , Tuberculosis Latente/inmunología , Tuberculosis Latente/prevención & control , Masculino , Mycobacterium tuberculosis/inmunología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tuberculosis/inmunología , VacunaciónRESUMEN
OBJECTIVE: Universal HIV testing of tuberculosis (TB) patients, defined as testing greater than 80% of incident cases, has been recommended but not achieved in Canada. The objectives of this study were: i) to assess the success of an 'opt-out' approach, whereby HIV testing is routine unless the patient specifically chooses otherwise, and ii) to determine the risk factors for HIV in patients tested before and after this approach was implemented. METHODS: TB and HIV databases in the province of Alberta were cross-matched before HAART (highly active anti-retroviral therapy) was available (1991-1997), after HAART but before 'opt-out' testing was implemented (1998-2002), and after 'opt-out' testing was implemented (2003-2006), and the HIV status of TB patients in each time period was described. The demographic and clinical characteristics of HIV-positive and -negative TB patients aged 15-64 years were compared. RESULTS: HIV testing of TB patients increased from 11.5% before HAART, to 44.9% after HAART but before 'opt-out' testing, to 81.9% after 'opt-out' testing was implemented. Between 1991 and 2006, 50 TB patients were diagnosed with HIV co-infection, all in the age group 15-64 years. Among TB patients aged 15-64 years who were HIV tested, those testing positive were significantly less likely to be female and to have respiratory TB and significantly more likely to have both respiratory and non-respiratory TB. The prevalence of HIV positivity in HIV-tested TB patients aged 15-64 years was 7.4% in 2003-2006. CONCLUSION: Universal HIV testing of TB patients is achievable through 'opt-out' HIV testing.
Asunto(s)
Serodiagnóstico del SIDA/estadística & datos numéricos , Infecciones por VIH/complicaciones , Infecciones por VIH/diagnóstico , Tamizaje Masivo/normas , Tuberculosis Pulmonar/complicaciones , Adolescente , Adulto , Alberta , Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa , Niño , Preescolar , Intervalos de Confianza , Bases de Datos Factuales , Estudios de Factibilidad , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Lactante , Recién Nacido , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Aceptación de la Atención de Salud , Sistema de Registros , Factores de Riesgo , Tuberculosis Pulmonar/epidemiología , Adulto JovenRESUMEN
UNLABELLED: BACKGROUND" Fluoroquinolone (FLQ) antibiotics are not uncommonly prescribed for community-acquired pneumonia that is later proven to be pulmonary tuberculosis (TB). Such FLQ monotherapy may result in FLQ-resistant pulmonary TB. METHODS: To assess outpatient FLQ use by patients with culture-proven pulmonary TB before diagnosis, TB registries in Alberta and Saskatchewan, Canada, were linked with provincial and federal drug benefit plans. To assess FLQ resistance, a case-control study was performed. RESULTS: Of 428 patients with pulmonary TB who were covered by a drug benefit plan, 74 (17.3%) had received > or = 1 FLQ prescription during the 6 months immediately before receipt of the diagnosis. Older patients (age, >64 years) were more likely than younger patients (age, 15-64 years) to be prescribed an FLQ (P < .05). Patients who were prescribed an FLQ received a total of 103 prescriptions. Most (54 [73.0%] of 74) patients who were prescribed an FLQ received a single prescription. Most (69 [67.0%] of 103) FLQ prescriptions were written within 90 days before the diagnosis of pulmonary TB. Patients who were prescribed an FLQ were not statistically significantly more likely than matched patients who were not prescribed an FLQ (control subjects) to be infected with FLQ-resistant Mycobacterium tuberculosis. Of 148 isolates of M. tuberculosis from patients and control subjects, 3 were FLQ resistant; all of these isolates were from patients who had received multiple FLQ prescriptions. Patients who had received multiple FLQ prescriptions were more likely than patients who had received a single FLQ prescription to be infected with FLQ-resistant M. tuberculosis (15.0% vs. 0.0%; odds ratio, 11.4; P = .04). CONCLUSIONS: Outpatient FLQ use, ostensibly for community-acquired pneumonia, is not uncommon among patients with pulmonary TB, especially older patients. Single FLQ prescriptions were not associated with FLQ-resistant M. tuberculosis, whereas multiple FLQ prescriptions were associated with FLQ resistance.
Asunto(s)
Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Farmacorresistencia Bacteriana , Fluoroquinolonas/uso terapéutico , Mycobacterium tuberculosis/efectos de los fármacos , Neumonía/tratamiento farmacológico , Tuberculosis Pulmonar/microbiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alberta , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Saskatchewan , Tuberculosis Pulmonar/diagnóstico , Adulto JovenRESUMEN
We used the Manitoba Health database to examine the relationship between use of inhaled respiratory drugs in people with chronic obstructive respiratory diseases and cardiovascular hospitalizations from 1996 through 2000. The drugs examined were beta agonists [BA], ipratropium bromide IB, and inhaled steroids (ICS). End points were first hospitalizations for supraventricular tachycardia, myocardial infarction, heart failure or stroke. A nested case control analysis was employed comparing people with and without cardiovascular events. Cases and controls were matched for gender and age, and conditional logistic regression was used in multivariate analysis considering other respiratory drugs, respiratory diagnosis and visit frequency, non-respiratory, non-cardiac comorbidities, and receipt of drugs for cardiovascular disease. In univariate analyses, BA, IB and ICS were all associated with hospitalizations for cardiovascular disease, but in multivariate analyses ICS did not increase risk while both BA and IB did. There were interactions between respiratory and cardiac drugs receipt in that bronchodilator associated risks were higher in people not taking cardiac drugs; this was especially true for stroke. There were strong interactions with specific cardiac drugs; for example, both BA and IB substantially increased the risk of supraventricular tachycardia in patients not anti-arryhthmic agents, but not in the presence of such agents. We conclude that bronchodilator therapy for chronic obstructive diseases is associated with increased cardiovascular risk, especially in patients without previous cardiovascular diagnoses, and that this is unlikely due to the severity of the respiratory disease, since risk was not increased with ICS.
Asunto(s)
Broncodilatadores/administración & dosificación , Enfermedades Cardiovasculares/epidemiología , Hospitalización/estadística & datos numéricos , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Administración por Inhalación , Anciano , Anciano de 80 o más Años , Enfermedades Cardiovasculares/terapia , Estudios de Casos y Controles , Bases de Datos Factuales , Femenino , Humanos , Masculino , Manitoba/epidemiología , Persona de Mediana EdadRESUMEN
UNLABELLED: We estimated the prevalence of asthma related symptoms in grade 7 and 8 students in a rural region in India. METHOD: An International Study of Asthma and Allergies in Childhood (ISAAC), questionnaire with added questions related to environmental and familial exposures, was administered to 3668 students from 48 rural schools near Malegaon, India. RESULTS: A history of asthma was present in 10.7% students and 7.3% wheezed in the past 12 months, with about one-third having at least four attacks. Boys had the higher prevalence of all asthma-related symptoms than girls did, and symptom frequency was generally above the median reported for urban Indian ISAAC centers. Asthma and wheeze were associated with a family history of asthma, smoking, and frequent chest colds. Significant environmental factors included parental occupation and smoking and poor water sources. Increased odds of asthma occurred in students working for wages, exposed to animals, or eating in the kitchen. Relationships were similar for wheezing. Both asthma and wheeze were higher in the Scheduled Tribe (ST) group. Most markers of socioeconomic status and environmental exposure were not significant in multivariate analysis. CONCLUSION: The prevalence of asthma and wheeze in a rural region in India was similar to that found in the urban ISAAC study; it was higher in students from lower socioeconomic groups with poorer environmental conditions.
Asunto(s)
Asma/epidemiología , Adolescente , Exposición a Riesgos Ambientales , Femenino , Humanos , India/epidemiología , Masculino , Prevalencia , Factores de Riesgo , Población Rural , Factores Socioeconómicos , Encuestas y CuestionariosRESUMEN
BACKGROUND: Pediatric tuberculosis (TB) is important medically and indicative of a public health problem. An understanding of the epidemiology and case characteristics of pediatric TB, in a province that accepts large numbers of immigrants, can inform TB elimination strategy. METHODS: All cases of pediatric TB notified in Alberta between 1990 and 2004 were identified in the TB Registry. Individual diagnostic criteria were reviewed and case patients were related to a population grid derived from Statistics Canada censuses and population estimates of Status Indians from the Department of Indian and Northern Affairs, Canada. Incidence rates were determined by ethnic group and gender. Clinical/mycobacteriologic case characteristics were compared by ethnic group and birth country. RESULTS: Among 124 notified cases, 95 (96 episodes) met strict diagnostic criteria: 45 Status Indians, 30 Canadian-born 'other' and 21 foreign-born. Incidence rates were much higher in Status Indians and the foreign-born compared to the Canadian-born 'other'; 10.7, 5.4, and 0.4 per 100,000 person-years, respectively. Among Canadian-born 'other' cases, 12 were Métis and 11 were Canadian-born children of foreign-born parents. Compared to foreign-born cases, Canadian-born cases were more likely to have a source case in Alberta, to be detected through contact tracing, to have primary pulmonary TB, and to have a rural address. CONCLUSION: Pediatric TB in Alberta is mainly the result of ongoing transmission in Aboriginal peoples and immigration to Canada of persons with latent TB infection. The elimination of pediatric TB will require interruption of transmission in Aboriginal peoples and prevention of disease in immigrants.
Asunto(s)
Pediatría , Tuberculosis/epidemiología , Adolescente , Alberta/epidemiología , Niño , Preescolar , Femenino , Humanos , Masculino , Sistema de RegistrosRESUMEN
OBJECTIVE: Airflow obstruction is relatively uncommon in young adults, and may indicate potential for the development of progressive disease. The objective of the present study was to enumerate and characterize airflow obstruction in a random sample of Canadians aged 20 to 44 years. SETTING: The sample (n=2962) was drawn from six Canadian sites. DESIGN: A prevalence study using the European Community Respiratory Health Survey protocol was conducted. Airflow obstruction was assessed by spirometry. Bronchial responsiveness, skin reactivity to allergens and total serum immunoglobulin E were also measured. Logistic regression was used for analysis. RESULTS: Airflow obstruction was observed in 6.4% of the sample, not associated with sex or age. The risk of airflow obstruction increased in patients who had smoked and in patients who had lung trouble during childhood. Adjusted for smoking, the risk of airflow obstruction was elevated for subjects with past and current asthma, skin reactivity to allergens, elevated levels of total immunoglobulin E and bronchial hyper-responsiveness. Of the subjects with airflow obstruction, 21% were smokers with a history of asthma, 50% were smokers without asthma, 12% were nonsmokers with asthma and 17% were nonsmokers with no history of asthma. Bronchial hyper-responsiveness increased the prevalence of airflow obstruction in each of these groups. CONCLUSION: Smoking and asthma, jointly and individually, are major determinants of obstructive disorders in young adults. Bronchial hyper-responsiveness contributes to obstruction in both groups.
Asunto(s)
Enfermedades Pulmonares Obstructivas/epidemiología , Adulto , Distribución por Edad , Asma/complicaciones , Canadá/epidemiología , Femenino , Encuestas Epidemiológicas , Humanos , Inmunoglobulina E/sangre , Enfermedades Pulmonares Obstructivas/sangre , Enfermedades Pulmonares Obstructivas/fisiopatología , Masculino , Pruebas de Función Respiratoria , Factores de Riesgo , Distribución por Sexo , Fumar/efectos adversosRESUMEN
BACKGROUND: On April 1, 2004, BCG (bacille Calmette-Guérin), a tuberculosis (TB) control vaccine, was discontinued in all but four high-risk communities in Alberta. To confirm the safety of vaccine withdrawal, and for future planning, the annual risk of infection (ARI) was determined in preschool First Nations children. METHODS: First Nations children born into reserve communities in Alberta between April 1, 1998 and March 31, 2004, and still living on reserve in 2004-2005, were identified. Health centre TB histories were validated by cross-referencing the birth cohort with the provincial TB Registry. Children that were not BCG vaccinated and not known to be tuberculin skin test (TST) positive underwent a TST. Birth cohort children were grouped as follows: (i) BCG vaccinated; (ii) BCG non-vaccinated, no TST; (iii) BCG non-vaccinated, TST; (iv) BCG vaccination status unknown. The ARI was calculated and the age and community characteristics of the groups were compared. RESULTS: There were 8447 children in the 6-year birth cohort, 4699 (55.6%) vaccinated, 2696 (31.9%) non-vaccinated, and 1052 (12.5%) whose vaccination status was unknown. Of the non-vaccinated children, 1921 (71.3%) were tested and only 2 were TST positive. No other TST positive, BCG non-vaccinated children were identified in the TB Registry cross-match. The prevalence of infection in 2004-2005 was 0.1% and the ARI was 0.03%. The community risk of TB exposure was comparable in tuberculin-tested and non-tested BCG non-vaccinated children. CONCLUSION: In low BCG-uptake First Nations communities in Alberta, the ARI is low and it is safe to withdraw BCG.
Asunto(s)
Vacuna BCG/provisión & distribución , Indígenas Norteamericanos/estadística & datos numéricos , Infecciones por Mycobacterium/epidemiología , Mycobacterium tuberculosis/aislamiento & purificación , Medición de Riesgo , Alberta/epidemiología , Preescolar , Femenino , Servicios de Salud del Indígena , Humanos , Incidencia , Masculino , Infecciones por Mycobacterium/prevención & control , Prevalencia , Prueba de TuberculinaRESUMEN
The contribution of respiratory viral infections to the onset of asthma and atopy is controversial. In "high risk" children (n = 455) born into asthmatic/atopic families, we determined the relationship of exposures to common respiratory viruses and concomitant respiratory symptoms, and to subsequent possible asthma and atopy at ages 1 and 2 years. Frozen nasal specimens, obtained when children were 2 weeks, 4, 8, and 12 months old, underwent reverse transcription-polymerase chain reaction (RT-PCR) testing for parainfluenza virus (PIV), respiratory syncytial virus (RSV), and picornavirus (rhinovirus/enterovirus). Odds ratios of viral RT-PCR results to respiratory symptoms ("cold," rhinitis, cough, wheezing) and to possible asthma or atopy at 1 and 2 years of age were calculated. Positive viral RT-PCR was associated with increased odds of "cold" and cough; PIV and picornavirus were associated with rhinitis, and RSV was associated with wheezing. PIV was associated with increased odds of atopy at 1 year of age in the control group; PIV and RSV were associated with possible asthma at 2 years of age. We conclude that in high-risk children, viral exposures documented by RT-PCR are associated with respiratory symptoms, and exposures to PIV and RSV during the first year of life are associated with the initial onset of possible asthma.
Asunto(s)
Asma/etiología , Asma/virología , Hipersensibilidad Inmediata/etiología , Hipersensibilidad Inmediata/virología , Infecciones del Sistema Respiratorio/complicaciones , Infecciones del Sistema Respiratorio/virología , Factores de Edad , Femenino , Humanos , Lactante , Masculino , Virus de la Parainfluenza 1 Humana , Picornaviridae , Virus Sincitial Respiratorio Humano , Factores de RiesgoRESUMEN
UNLABELLED: SUBJECTIVE OBJECTIVES: To document healthcare utilization 2 years after diagnosis in women with obstructive sleep apnea syndrome (OSAS). DESIGN: Retrospective observational cohort study. SETTING: Tertiary university-based medical center. PATIENTS AND CONTROLS: Four hundred and fourteen women with OSAS were matched with 1404 women from the general population who served as controls. INTERVENTIONS: Patients were treated with continuous positive airway pressure (CPAP) or were recommended weight loss alone. MEASUREMENTS AND RESULTS: There were 231 treatment compliant (TC) patients, 91 patients not using CPAP (NCU), and 92 patients who were only recommended weight loss (WL). In the entire group, there was increase in fees of $123.43+/-$25.01 in the 2 years before diagnosis and a reduction of fees of $37.96+/-$21.35 in the 2 years after diagnosis (p < .0001). Physician claims increased in the 2 years before diagnosis by $111.22+/-31.35 in TC and by $152.77+/-59.55 in the NCU groups and then decreased in TC by $20.96+/-$26.60 (p < .01) and NCU by $72.20 +/-45.91 in the 2 years after diagnosis (p < .01). The fees in WL group did not change significantly. The number of clinic visits of the entire group increased in the 2 years before diagnosis by 2.32+/-0.43 and decreased over the next 2 years by 1.48+/-0.42 visits (p < .0001). There was an increase of clinic visits in the 3 subgroups in the 2 years before diagnosis (2.30+/-0.57 in TC, 2.55+/-0.99 in NCU, and 2.18+/-0.82 in WL groups) followed by a reduction of clinic visits over the next 2 years (1.56+/-0.55 fewer visits in TC [p < .0001], 1.70+/-0.90 in NCU [p < .01], and 1.04+/-0.90 in the WL group [p < .05] ). CONCLUSIONS: Healthcare utilization in women with OSAS increased in the years before sleep-clinic evaluation and then decreased in the following 2 years.
Asunto(s)
Presión de las Vías Aéreas Positiva Contínua/métodos , Apnea Obstructiva del Sueño/diagnóstico , Apnea Obstructiva del Sueño/terapia , Índice de Masa Corporal , Presión de las Vías Aéreas Positiva Contínua/economía , Costos y Análisis de Costo , Femenino , Humanos , Persona de Mediana Edad , Polisomnografía , Índice de Severidad de la Enfermedad , Apnea Obstructiva del Sueño/economíaRESUMEN
STUDY OBJECTIVES: To assess the influence of inhaled corticosteroids (ICSs) on mortality in COPD patients, which is currently a controversial topic. SETTING: Manitoba Health maintains a population-wide research database that includes pharmaceutical information. DESIGN AND PATIENTS: We examined mortality in people 90 to 365 days after hospital discharge for COPD, comparing those persons who received inhaled steroids within 90 days of hospital discharge with those who did not. Cox proportional hazards models were used with adjustments for other respiratory drugs, comorbidities, and physician visits before and after hospital discharge. We also compared mortality in patients who received inhaled steroids with those who received other respiratory drugs, but not inhaled steroids, and those who received neither. Using nested case control analysis, we examined the time of receipt of inhaled steroids in relation to fatal events. RESULTS: In people > 65 years of age, inhaled steroids were associated with a 25% reduction in mortality between 90 and 365 days after hospital discharge, while mortality increased with bronchodilator use, physician visits, age, and comorbidities. The exclusion of people who had also received a diagnosis of asthma or had received inhaled steroids before hospitalization did not change the result. Inhaled steroids were associated with an even larger mortality reduction in people aged 35 to 64 years. People who received bronchodilators but no steroids had higher mortality than people who received no bronchodilators or received both bronchodilators and inhaled steroids. The reduction in all-cause mortality was largely due to the decreased number of cardiovascular deaths. The receipt of inhaled steroids within 30 days of death was protective, but this was not the case for greater time intervals. CONCLUSIONS: Therapy with ICSs reduced mortality in COPD patients; the effect was particularly notable for cardiovascular death and was short term in that it was dependent on recent exposure.
Asunto(s)
Corticoesteroides/administración & dosificación , Corticoesteroides/uso terapéutico , Enfermedades Cardiovasculares/mortalidad , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/mortalidad , Administración por Inhalación , Adulto , Asma/epidemiología , Broncodilatadores/efectos adversos , Broncodilatadores/uso terapéutico , Enfermedades Cardiovasculares/etiología , Estudios de Casos y Controles , Comorbilidad , Bases de Datos como Asunto , Femenino , Humanos , Masculino , Manitoba/epidemiología , Persona de Mediana Edad , Alta del Paciente/estadística & datos numéricos , Modelos de Riesgos Proporcionales , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/patología , Tasa de SupervivenciaRESUMEN
BACKGROUND: A worldwide increase has been noted in the prevalence of asthma, but the data for other allergic disorders are less consistent. OBJECTIVE: To study 14-year trends in utilization of physician resources for asthma and compare them to trends for allergic rhinitis. METHODS: We studied visits to physicians by Manitoba residents for asthma (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 493) and allergic rhinitis (ICD-9 code 477) between 1985 and 1998. Prevalence and incidence of physician resources utilization were calculated annually for the total population and by age groups. Aggregate statistics and frequency of physician resources utilization were also analyzed. RESULTS: The prevalence and incidence of physician resources utilization for asthma increased more than for allergic rhinitis; differences were most striking in the youngest age groups. In adults, the differences were smaller and changed little with time. Most of the increase in asthma care occurred in children and in people without allergic rhinitis. Overall, 17% of Manitobans were diagnosed as having asthma, and the average asthmatic patient made 6 visits. Approximately 14% had an allergic rhinitis diagnosis, each person being seen twice on average. Coexistence of asthma and allergic rhinitis led to increased physician resources utilization for each of the conditions. CONCLUSIONS: Trends in utilization of physician resources for allergic rhinitis differed strikingly from trends for asthma, particularly in the youngest age group. Asthma and allergic rhinitis affected comparable proportions of the population, but a diagnosis of asthma resulted in much higher utilization of physician resources. The relationship of physician-diagnosed asthma and atopy, as indicated by the diagnosis of allergic rhinitis, appears to have weakened with time in children but not in adults.
Asunto(s)
Asma/epidemiología , Rinitis Alérgica Perenne/epidemiología , Rinitis Alérgica Estacional/epidemiología , Adolescente , Adulto , Factores de Edad , Niño , Preescolar , Femenino , Necesidades y Demandas de Servicios de Salud/tendencias , Humanos , Incidencia , Lactante , Masculino , Manitoba/epidemiología , Persona de Mediana Edad , Prevalencia , Estudios RetrospectivosRESUMEN
PURPOSE: To estimate incidence rates for dementia and the impact of subject attrition on these rates. METHODS: Crude, age- and gender-specific incidence rates of dementia and Alzheimer's disease were calculated using person-years analysis and Cox proportional hazard models in a population-based cohort study of 1952 adults aged 65+ years in Manitoba, Canada. Rates were standardized to the nondemented population using the direct method. Ratios of incidence rates comparing completers to subjects who had died, refused, or were unavailable for follow up were based on health care utilization data (available for all subject groups) and used to adjust rates for attrition. RESULTS: Decedents had a significantly higher incidence of dementia than did subjects who completed the follow-up assessment. The incidence in subjects who refused or were unavailable at follow up was intermediate between decedents and completers. Adjusted for attrition, the standardized dementia incidence rate for community and institutional subjects was 25.3/1000 person-years, significantly higher than that based on follow-up assessments only (17.8/1000 person-years; 95% confidence interval: 14.3-21.4). CONCLUSIONS: The impact of loss to follow up on incidence rates varies depending on the reason for subject attrition. Incidence studies of dementia should develop strategies to characterize and address subject attrition to avoid underestimating disease incidence.
Asunto(s)
Demencia/epidemiología , Factores de Edad , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/epidemiología , Femenino , Servicios de Salud/estadística & datos numéricos , Humanos , Incidencia , Masculino , Factores SexualesRESUMEN
STUDY OBJECTIVES: Patients with untreated obstructive sleep apnea syndrome (OSAS) have higher healthcare utilization than matched controls. However, the long-term impact of continuous positive airway pressure (CPAP) use on healthcare utilization is unknown. DESIGN: Retrospective observational cohort study. SUBJECTS: There were 342 eligible men with OSAS and matched controls on whom there were utilization data for 5 years prior to initial OSAS diagnosis and for the 5 years on CPAP treatment of the cases. INTERVENTIONS: Patients were treated with CPAP. RESULTS: Patients with OSAS were typical cases (mean +/- SD): age, 48.2 +/- 0.6 years; body mass index, 35.6 +/- 0.4 kg/m2; Epworth Sleepiness Scale score, 14.2 +/- 0.3; apnea-hypopnea index, 47.1 +/- 1.8 events per hour. The number of physician visits were higher by 3.46 +/- 0.2 (95% confidence interval [CI]: 2.57 to 4.36) in cases in the year before diagnosis, compared with the fifth year before diagnosis, then decreased over the next 5 years by 1.03 +/- 0.49 (95% CI: -1.99 to -0.07)(P<.0001). Physician fees, in Canadian dollars, were higher by dollars 148.65 +/- dollars 27.27 (95% CI: 95.12 to 202.10) in cases in the year before diagnosis, compared with the fifth year before diagnosis, and then decreased over the next 5 years by dollars 13.92 +/- dollars 27.94(95%CI: -68.68 to 40.83)(P=.0009). Preexisting ischemic heart disease at the time of OSAS diagnosis predicted about a 5-fold increase in healthcare utilization between the second and fifth year of treatment. CONCLUSIONS: Treatment of OSAS reversed the trend of increasing healthcare utilization seen prior to diagnosis. Preexisting ischemic heart disease results in a negative impact on healthcare utilization. CPAP results in a long-term health benefit, as measured by the use of healthcare services.
Asunto(s)
Presión de las Vías Aéreas Positiva Contínua/economía , Servicios de Salud/economía , Servicios de Salud/estadística & datos numéricos , Apnea Obstructiva del Sueño/economía , Apnea Obstructiva del Sueño/terapia , Adulto , Análisis Costo-Beneficio , Electroencefalografía , Electromiografía , Estudios de Seguimiento , Gastos en Salud , Humanos , Masculino , Manitoba , Persona de Mediana Edad , Polisomnografía , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Apnea Obstructiva del Sueño/diagnósticoRESUMEN
BACKGROUND: The space and time distribution of risk factors for allergic diseases may provide insights into disease mechanisms. Allergy is believed to vary by month of birth, but multinational studies taking into account latitude have not been conducted. METHODS AND FINDINGS: A questionnaire was distributed in 54 centres to a representative sample of 20- to 44-y-old men and women mainly in Europe but also including regions in North Africa, India, North America, Australia, and New Zealand. Data from 200,682 participants were analyzed. The median prevalence of allergic rhinitis was 22%, with a substantial variation across centres. Overall, allergic rhinitis decreased with geographical latitude, but there were many exceptions. No increase in prevalence during certain winters could be observed. Also, no altered risk by birth month was found, except borderline reduced risks in September and October. Effect estimates obtained by a multivariate analysis of total and specific IgE values in 18,085 individuals also excluded major birth month effects and confirmed the independent effect of language grouping. CONCLUSION: Neither time point of first exposure to certain allergens nor early infections during winter months seems to be a major factor for adult allergy. Although there might be effects of climate or environmental UV exposure by latitude, influences within language groups seem to be more important, reflecting so far unknown genetic or cultural risk factors.
Asunto(s)
Hipersensibilidad/epidemiología , Hipersensibilidad/fisiopatología , Adulto , Alérgenos , Exposición a Riesgos Ambientales , Femenino , Geografía , Encuestas Epidemiológicas , Humanos , Lenguaje , Masculino , Parto , Prevalencia , Características de la Residencia , Factores de Riesgo , Estaciones del AñoRESUMEN
BACKGROUND: Randomized clinical trials have not yet demonstrated the mortality benefit of smoking cessation. OBJECTIVE: To assess the long-term effect on mortality of a randomly applied smoking cessation program. DESIGN: The Lung Health Study was a randomized clinical trial of smoking cessation. Special intervention participants received the smoking intervention program and were compared with usual care participants. Vital status was followed up to 14.5 years. SETTING: 10 clinical centers in the United States and Canada. PATIENTS: 5887 middle-aged volunteers with asymptomatic airway obstruction. MEASUREMENTS: All-cause mortality and mortality due to cardiovascular disease, lung cancer, and other respiratory disease. INTERVENTION: The intervention was a 10-week smoking cessation program that included a strong physician message and 12 group sessions using behavior modification and nicotine gum, plus either ipratropium or a placebo inhaler. RESULTS: At 5 years, 21.7% of special intervention participants had stopped smoking since study entry compared with 5.4% of usual care participants. After up to 14.5 years of follow-up, 731 patients died: 33% of lung cancer, 22% of cardiovascular disease, 7.8% of respiratory disease other than cancer, and 2.3% of unknown causes. All-cause mortality was significantly lower in the special intervention group than in the usual care group (8.83 per 1000 person-years vs. 10.38 per 1000 person-years; P = 0.03). The hazard ratio for mortality in the usual care group compared with the special intervention group was 1.18 (95% CI, 1.02 to 1.37). Differences in death rates for both lung cancer and cardiovascular disease were greater when death rates were analyzed by smoking habit. LIMITATIONS: Results apply only to individuals with airway obstruction. CONCLUSION: Smoking cessation intervention programs can have a substantial effect on subsequent mortality, even when successful in a minority of participants.
Asunto(s)
Mortalidad , Enfermedad Pulmonar Obstructiva Crónica/terapia , Cese del Hábito de Fumar/métodos , Terapia Conductista , Broncodilatadores/uso terapéutico , Causas de Muerte , Femenino , Estudios de Seguimiento , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Ipratropio/uso terapéutico , Masculino , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/etiología , Fumar/efectos adversos , Fumar/fisiopatología , Prevención del Hábito de FumarRESUMEN
OBJECTIVE: The objective of this cohort study was to determine if complications of pregnancy and labor, characteristics at birth, and exposure to infections influence the incidence of asthma in the first 6 years of life. DESIGN: We identified all children born between 1980 and 1990 in the Province of Manitoba, Canada. We used records of physician contacts (inpatient and outpatient) and services of the universal provincial health insurance plan to follow up 170,960 children from birth to the age of 6 years to identify the first diagnosis of asthma. Information on mothers and siblings was also obtained to determine family history of disease and exposure to infections. RESULTS: During the study period, a diagnosis of asthma was made in 14.1% of children by the age of 6 years. The incidence was higher in boys than in girls, in those with family history of allergic diseases. It was higher in urban than in rural areas, and lowest in those born in winter. Asthma was more likely in those with low birth weight and premature birth. Certain congenital abnormalities and complications of pregnancy and labor also increased the risk of asthma. The risk of asthma increased with maternal age. Both upper and lower respiratory infections increased the risk of subsequent asthma, and this effect was more important than exposure to familial respiratory infections, which also tended to increase asthma risk. The risk of asthma decreased with the number of siblings when siblings had a history of allergic disorders. CONCLUSIONS: In addition to genetic influences, intrauterine and labor conditions are determinants of asthma. Exposure to both upper and lower respiratory tract infections increases the risk; these infections do not explain the protective effect associated with the increasing number of siblings.
Asunto(s)
Asma/epidemiología , Niño , Preescolar , Estudios de Cohortes , Comorbilidad , Salud de la Familia , Femenino , Edad Gestacional , Humanos , Incidencia , Lactante , Masculino , Manitoba/epidemiología , Complicaciones del Trabajo de Parto/epidemiología , Embarazo , Complicaciones del Embarazo/epidemiología , Factores de Riesgo , Población Rural , Estaciones del Año , Población UrbanaRESUMEN
BACKGROUND: Tuberculous lymphadenitis (TBL) is an important form of extrapulmonary tuberculosis (TB). Recent studies have shown an increase in TBL in Canada. OBJECTIVES: To determine the incidence of TBL in Manitoba and to identify the characteristics associated with its presentation, diagnosis and treatment METHODS: Population data from the Manitoba Health Population Registry, the First Nations and Inuit Health Branch of Health Canada, and Statistics Canada were used to calculate incidence. Case characteristics and outcomes were determined by a systematic, retrospective review of all cases between January 1, 1990 and December 31, 2000. RESULTS: One-hundred forty seven cases of TBL were identified during the study period; 77% confirmed by culture; 68% women. TBL was found in Canadian-born/nonstatus Aboriginal (12%), status Aboriginal (29%) and foreign-born (59%) populations. Incidence of TBL was 1.17 per 100,000 person years (95% CI 0.98 to 1.36). The highest incidence was in status Aboriginals over 65 years (16.85 per 100,000 person years; 95% CI 3.37 to 30.33). TBL is seen most often in Western Pacific women. The most common presentation was a single, enlarged cervical node (80%). No atypical mycobacterium was found. Drug resistance occurred in 13% of cases and only in the foreign-born. Cure rates (81%) were influenced by comorbidity and burden of TB disease. Relapse occurred in 8.1 per 1000 person years of follow-up (95% CI 1.7 to 23.7). CONCLUSIONS: Respiratory physicians, who manage the majority of TB disease in Canada, need to remain aware that TB is an important and treatable cause of enlarged lymph nodes.
Asunto(s)
Tuberculosis Ganglionar/epidemiología , Adolescente , Adulto , Antituberculosos/uso terapéutico , Biopsia con Aguja Fina , Niño , Preescolar , Comorbilidad , Farmacorresistencia Microbiana , Femenino , Humanos , Incidencia , Lactante , Masculino , Manitoba/epidemiología , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Tuberculosis Ganglionar/diagnóstico , Tuberculosis Ganglionar/tratamiento farmacológico , Tuberculosis Ganglionar/patologíaRESUMEN
OBJECTIVES: Geographic variability in reported prevalences of asthma worldwide could in part relate to interpretation of symptoms and diagnostic biases. Bronchial responsiveness measurements provide objective evidence of a common physiologic characteristic of asthma. We measured bronchial responsiveness using the standardized protocol of the European Community Respiratory Health Survey (ECRHS) in six sites in Canada, and compared prevalences across Canada with international sites. DESIGN: Samples of 3,000 to 4,000 adults aged 20 to 44 years were randomly selected in Vancouver, Winnipeg, Hamilton, Montreal, Halifax, and Prince Edward Island, and a mail questionnaire was completed by 18,616 individuals (86.5%). Preselected random subsamples (n = 2,962) attended a research laboratory for examination including more detailed questionnaires, lung function testing including methacholine challenge, and skin testing with 14 allergens. RESULTS: Prevalences of bronchial hyperresponsiveness, measured as cumulative dose of methacholine required to produce a 20% fall from the post-saline solution FEV1 < or = 1 mg, ranged from 4.9% (95% confidence interval [CI], 1.6 to 8.5) in Halifax to 22.0% (95% CI, 18.1 to 26.0) in Hamilton (median, 10.7%). In all Canadian sites, bronchial hyperresponsiveness was more prevalent in women than in men. Neither the geographic nor gender differences were accounted for by differences in age, smoking, skin test reactivity, or baseline FEV1. Geographic- and gender-related variability changed little when only bronchial hyperresponsiveness associated with asthma-like symptoms was considered. CONCLUSIONS: A wide variability in bronchial responsiveness can occur within one country, almost as wide as the range found across all international sites participating in the ECRHS study and not explained by differences in gender, smoking, skin test reactivity, and FEV1. While gender variability in the prevalence of bronchial responsiveness is likely due to hormonal and immunologic factors, geographic variability is likely to result from environmental factors.