Data enhancement for co-morbidity measurement among patients referred for sleep diagnostic testing: an observational study

<p>Abstract</p> <p>Background</p> <p>Observational outcome studies of patients with obstructive sleep apnea (OSA) require adjustment for co-morbidity to produce valid results. The aim of this study was to evaluate whether the combination of administrative data and self-reported data provided a more complete estimate of co-morbidity among patients referred for sleep diagnostic testing.</p> <p>Methods</p> <p>A retrospective observational study of 2149 patients referred for sleep diagnostic testing in Calgary, Canada. Self-reported co-morbidity was obtained with a questionnaire; administrative data and validated algorithms (when available) were also used to define the presence of these co-morbid conditions within a two-year period prior to sleep testing.</p> <p>Results</p> <p>Patient self-report of co-morbid conditions had varying levels of agreement with those derived from administrative data, ranging from substantial agreement for diabetes (κ = 0.79) to poor agreement for cardiac arrhythmia (κ = 0.14). The enhanced measure of co-morbidity using either self-report or administrative data had face validity, and provided clinically meaningful trends in the prevalence of co-morbidity among this population.</p> <p>Conclusion</p> <p>An enhanced measure of co-morbidity using self-report and administrative data can provide a more complete measure of the co-morbidity among patients with OSA when agreement between the two sources is poor. This methodology will aid in the adjustment of these coexisting conditions in observational studies in this area.</p

Cerebrovascular pulsatility in patients with sleep-disordered breathing

PURPOSE: The aim of our study is to determine the association between the pulsatility index (PI), a surrogate of cerebral small vessel disease and sleep-disordered breathing (SDB). METHODS: We conducted a transcranial Doppler ultrasound (TCD) study of 19 consecutive patients free of stroke and cardiovascular disease, referred for the evaluation of SDB. TCD was performed by a certified technologist. Subsequent polysomnography was performed according to the practice parameters of the American Academy of Sleep Medicine. We evaluated the association between the apnea–hypopnea index (AHI), the oxygen nadir, the blood flow velocities, and the Gosling PI, for the middle cerebral artery. We performed Spearman’s rank correlation and nonparametric regression to evaluate the relationship between AHI, oxygen levels, and the PI. RESULTS: Median age was 48 years (range 37–83), with 52 % male sex (n=10), and median BMI of 29.9 (range 25–40.4). The median AHI was 16.4 (0.2–69). The median PI was 0.97 (0.72–1.89) cm/s. The PI correlated with the AHI (rho=0.44; p=0.004) and with age (rho=0.57; p=0.001). Nonparametric regression adjusting for age showed a positive association between the AHI and the PI (standardized estimate=0.88; p=0.002). There was no relation between the oxygen nadir and the PI. CONCLUSION: We observed increased PI in patients with SDB during wakefulness. The PI could potentially be an estimate of cerebral small vessel disease in patients with SDB and hence allow evaluating cerebral hemodynamics during wakefulness with a clinically relevant device

Condições socioeconômicas estão associadas ao overbite e overjet? Uma avaliação utilizando fotografias digitais

OBJETIVO: estimar a associação entre fatores socioeconômicos e más oclusões do tipo overbite e overjet em escolares em fase de dentição permanente jovem. MÉTODO: trata-se de um estudo transversal realizado em 251 escolares de sete a 15 anos, de ambos os sexos, regularmente matriculadas no ensino fundamental de escolas públicas e privadas do município de São Luís, Maranhão, Brasil. Todos os sujeitos da amostra realizaram fotografias extrabucais padronizadas de face (frontal em repouso, frontal sorrindo e perfil) e intrabucais (frontal, lateral direita e lateral esquerda em oclusão, oclusal superior e oclusal inferior), para o diagnóstico das alterações. As fotografias foram avaliadas por três examinadores em regime cego e as discordâncias foram discutidas até a obtenção de consenso. Overbite e overjet foram diagnosticados segundo critérios de Angle. RESULTADOS: constatou-se que 35,4% das crianças apresentaram overbite e 18,3%, overjet. Houve associação estatisticamente significante entre a renda familiar com overbite (p=0.003) e com overjet (p=0.029), observando-se que a maioria das crianças que não possuíam overbite (69,4%) era de famílias com baixa renda (até 2 salários mínimos). De modo semelhante, a maioria dos portadores de overjet era de famílias com renda mais elevada, ao passo que a maioria daqueles sem overjet tinha renda familiar baixa. Para as demais variáveis não houve diferenças estatisticamente significante na distribuição de frequência de overjet e overbite. CONCLUSÃO: a prevalência de overbite e overjet nos escolares estudados é alta, especialmente entre aqueles com maior renda familiar