Felipe Aizpuru

Severe sleep apnea and risk of ischemic stroke in the elderly.

Background and Purpose— Convincing evidence of a causal relationship between sleep apnea and stroke has been shown recently in several prospective, well-designed studies. However, these studies have focused on middle-aged people, excluding the elderly population from analysis. To investigate whether sleep apnea represents an independent risk factor in this population, we performed a prospective longitudinal study in a population-based cohort of subjects from 70 to 100 years old. Methods— Within the context of the Vitoria Sleep Project, a population-based study designed to investigate the prevalence of sleep apnea in the population of Vitoria, Spain, we performed a 6-year longitudinal study in a subsample cohort of 394 noninstitutionalized, initially event-free subjects (70 to 100 years old, median 77.28 years, 57.1% males). Demographic and polysomnographic data and known confounding factors (age, sex, smoking and alcohol consumption status, body mass index, systolic and diastolic blood pressure, total serum cholesterol levels, and the presence or absence of diabetes mellitus, atrial fibrillation, and hypertension) were assessed at baseline. Hazard ratio for developing an ischemic stroke in relation to the apnea-hypopnea index at baseline was calculated. Results— Over the 6-year follow-up period, 20 ischemic strokes were registered. After adjustment for confounding factors, subjects with severe obstructive sleep apnea hypopnea (defined as apnea-hypopnea index ≥30) at baseline had an increased risk of developing a stroke (hazard ratio=2.52, 95% CI=1.04 to 6.01, P=0.04). Conclusions— This study shows that severe obstructive sleep apnea hypopnea (defined as apnea-hypopnea index ≥30) increases the risk of ischemic stroke in the elderly population, independent of known confounding factors.

Effect of CPAP on Blood Pressure in Patients With Obstructive Sleep Apnea and Resistant Hypertension The HIPARCO Randomized Clinical Trial

IMPORTANCE More than 70% of patients with resistant hypertension have obstructive sleep apnea (OSA). However, there is little evidence about the effect of continuous positive airway pressure (CPAP) treatment on blood pressure in patients with resistant hypertension. OBJECTIVE To assess the effect of CPAP treatment on blood pressure values and nocturnal blood pressure patterns in patients with resistant hypertension and OSA. DESIGN, SETTING, AND PARTICIPANTS Open-label, randomized, multicenter clinical trial of parallel groups with blinded end point design conducted in 24 teaching hospitals in Spain involving 194 patients with resistant hypertension and an apnea-hypopnea index (AHI) of 15 or higher. Data were collected from June 2009 to October 2011. INTERVENTIONS CPAP or no therapy while maintaining usual blood pressure control medication. MAIN OUTCOMES AND MEASURES The primary end point was the change in 24-hour mean blood pressure after 12 weeks. Secondary end points included changes in other blood pressure values and changes in nocturnal blood pressure patterns. Both intention-to-treat (ITT) and per-protocol analyses were performed. RESULTS A total of 194 patients were randomly assigned to receive CPAP (n = 98) or no CPAP (control; n = 96). The mean AHI was 40.4 (SD, 18.9) and an average of 3.8 antihypertensive drugs were taken per patient. Baseline 24-hour mean blood pressure was 103.4 mm Hg; systolic blood pressure (SBP), 144.2 mm Hg; and diastolic blood pressure (DBP), 83 mm Hg. At baseline, 25.8% of patients displayed a dipper pattern (a decrease of at least 10% in the average nighttime blood pressure compared with the average daytime blood pressure). The percentage of patients using CPAP for 4 or more hours per day was 72.4%. When the changes in blood pressure over the study period were compared between groups by ITT, the CPAP group achieved a greater decrease in 24-hour mean blood pressure (3.1 mm Hg [95% CI, 0.6 to 5.6]; P = .02) and 24-hour DBP (3.2 mm Hg [95% CI, 1.0 to 5.4]; P = .005), but not in 24-hour SBP (3.1 mm Hg [95% CI, -0.6 to 6.7]; P = .10) compared with the control group. Moreover, the percentage of patients displaying a nocturnal blood pressure dipper pattern at the 12-week follow-up was greater in the CPAP group than in the control group (35.9% vs 21.6%; adjusted odds ratio [OR], 2.4 [95% CI, 1.2 to 5.1]; P = .02). There was a significant positive correlation between hours of CPAP use and the decrease in 24-hour mean blood pressure (r = 0.29, P = .006), SBP (r = 0.25; P = .02), and DBP (r = 0.30, P = .005). CONCLUSIONS AND RELEVANCE Among patients with OSA and resistant hypertension, CPAP treatment for 12 weeks compared with control resulted in a decrease in 24-hour mean and diastolic blood pressure and an improvement in the nocturnal blood pressure pattern. Further research is warranted to assess longer-term health outcomes. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00616265.

Predictors of patient satisfaction with hospital health care

BackgroundWe used a validated inpatient satisfaction questionnaire to evaluate the health care received by patients admitted to several hospitals. This questionnaire was factored into distinct domains, creating a score for each to assist in the analysis.We evaluated possible predictors of patient satisfaction in relation to socio-demographic variables, history of admission, and survey logistics.MethodsCross-sectional study of patients discharged from four acute care general hospitals. Random sample of 650 discharged patients from the medical and surgical wards of each hospital during February and March 2002. A total of 1,910 patients responded to the questionnaire (73.5%). Patient satisfaction was measured by a validated questionnaire with six domains: information, human care, comfort, visiting, intimacy, and cleanliness. Each domain was scored from 0 to 100, with higher scores indicating higher levels of patient satisfaction.ResultsIn the univariate analysis, age was related to all domains except visiting; gender to comfort, visiting, and intimacy; level of education to comfort and cleanliness; marital status to information, human care, intimacy, and cleanliness; length of hospital stay to visiting and cleanliness, and previous admissions to human care, comfort, and cleanliness. The timing of the response to the mailing and who completed the questionnaire were related to all variables except visiting and cleanliness. Multivariate analysis confirmed in most cases the previous findings and added additional correlations for level of education (visiting and intimacy) and marital status (comfort and visiting).ConclusionThese results confirm the varying importance of some socio-demographic variables and length of stay, previous admission, the timing of response to the questionnaire, and who completed the questionnaire on some aspects of patient satisfaction after hospitalization. All these variables should be considered when evaluating patient satisfaction.

Obstructive Sleep Apnea and Systemic Hypertension

RATIONALE Obstructive sleep apnea and systemic hypertension (SH) are highly prevalent. Although their association has been suggested in cross-sectional studies, conflicting evidence has emerged from longitudinal studies. OBJECTIVES To assess the association between obstructive sleep apnea and SH in the middle-aged general population. METHODS A total of 2,148 subjects were included in a longitudinal study of the Vitoria Sleep Cohort, a general population sample aged 30-70 years. We analyzed data on office blood pressure, anthropometric measures, health history, and home polygraphy. Out of 1,557 subjects who completed the 7.5-year follow-up, 377 were excluded for having SH at baseline. The odds ratios for the incidence of SH, according to the respiratory disturbance index (RDI) at baseline, were estimated in 1,180 subjects (526 men and 654 women) after adjustment for age; sex; body mass index; neck circumference; fitness level; and alcohol, tobacco, and coffee consumption. The RDI was divided into quartiles (0-2.9, 3-6.9, 7-13.9, and ≥ 14), using the first quartile as reference. MEASUREMENTS AND MAIN RESULTS The crude odds ratio for incident hypertension increased with higher RDI category with a dose-response effect (P < 0.001), but was not statistically significant after adjustment for age (P = 0.051). Adjustments for sex (P = 0.342), body mass index (P = 0.803), neck circumference (P = 0.885), and fitness level and alcohol, tobacco, and coffee consumption (P = 0.708) further reduced the strength of the association between RDI and SH. No differences were observed between men and women. CONCLUSIONS Our findings do not suggest an association between obstructive sleep apnea and the incidence of SH in the middle-aged general population. Long-term follow-up longitudinal studies are needed to better ascertain this association.

Obstructive sleep apnea/hypopnea and systemic hypertension

Obstructive sleep apnea/hypopnea (OSAH) syndrome is a highly prevalent condition. Severe OSAH affects 2-6% of the population, although only 10% of subjects are correctly diagnosed and treated. OSAH is an important and unresolved public health care problem because of its role in the development of cardiovascular events, negative impact on quality of life, and as a cause of traffic accidents. Longitudinal and cross-sectional studies have shown a strong association between OSAH and hypertension. Moreover, a number of open-label studies, the majority of 21 controlled studies included in the present review, a systematic review, and 4 recent meta-analyses have shown a reduction of blood pressure (BP) of about 2 mm Hg with continuous positive airway pressure (CPAP). This lowering of blood pressure is significant in terms of reduction of both cardiovascular and cerebrovascular risk and death. The effect is greater in hypertensive subjects and in those with more severe OSAH. Accordingly, treatment with CPAP could be considered in patients with severe OSAH and hypertension even in the absence of symptoms. The challenge to researchers is to find markers for discriminating subjects in whom blood pressure will decrease from non-responders. This will help to refine relevant clinical indicators for CPAP treatment in clinical practice.

Patient Expectations and Health-Related Quality of Life Outcomes Following Total Joint Replacement

OBJECTIVES Patient psychological factors have been linked to health-related quality of life (HRQoL) outcomes after total joint replacement (TJR). We evaluated the relationship between patient expectations before TJR, their fulfillment and HRQoL outcomes at 3 and 12 months after surgery. METHODS Consecutive patients preparing for TJR of the knee or hip due to primary osteoarthritis in 15 hospitals in Spain were recruited for the study. Patients completed questionnaires before surgery, and 3 and 12 months afterward: five questions about expectations before surgery and their fulfillment at 3 and 12 months; three HRQoL instruments-Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form 12 (SF-12), and European Quality of Life Instrument (EQ-5D); as well as questions about sociodemographic information. Students t test was used to assess the relationship between fulfillment of expectations and gains in HRQoL. RESULTS A total of 881 patients took part in the study. Preintervention expectations for TJR ranged from 85% to 86% of patients, with high expectations for pain relief and ability to walk to 70% with high expectations about interacting with others. Patients who reported having fulfilled their expectations at 3 and 12 months had significantly greater gains in HRQoL than those who did not. Besides, we observed a statistically significant improvement in the percentage of patients who fulfill their expectations from 3 to 12 months. CONCLUSIONS Patients have high expectations for the benefits of TJR, and those who fulfill their expectations have greater gains in HRQoL assessing by SF-12, WOMAC and EQ-5D. Health-care providers should help their patients develop realistic expectations about the impact of TJR.

Efficacy of Different Treatment Alternatives for Obesity Hypoventilation Syndrome. Pickwick Study

RATIONALE The incidence of obesity hypoventilation syndrome (OHS) may be increasing in parallel with the present obesity epidemic. Despite extensive noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP) use in patients with OHS, information regarding efficacy is limited. OBJECTIVES We performed a large, multicenter randomized controlled study to determine the comparative efficacy of NIV, CPAP, and lifestyle modification (control group) using daytime PaCO2 as the main outcome measure. METHODS Sequentially screened patients with OHS with severe sleep apnea were randomized into the above-mentioned groups for a 2-month follow up. Arterial blood gas parameters, clinical symptoms, health-related quality-of-life assessments, polysomnography, spirometry, 6-minute-walk distance, dropouts, compliance, and side effects were evaluated. Statistical analysis was performed using intention-to-treat analysis, although adjustments for CPAP and NIV compliance were also analyzed. MEASUREMENTS AND MAIN RESULTS In total, 351 patients were selected, and 221 were randomized. NIV yielded the greatest improvement in PaCO2 and bicarbonate, with significant differences relative to the control group but not relative to the CPAP group. In the CPAP group, PaCO2 improvement was significantly different than in the control group only after CPAP compliance adjustment. Additionally, clinical symptoms and polysomnographic parameters improved similarly with NIV and CPAP relative to the control. However, some health-related quality-of-life assessments, the spirometry, and 6-minute-walk distance results improved more with NIV than with CPAP. Dropouts were similar between groups, and compliance and secondary effects were similar between NIV and CPAP. CONCLUSIONS NIV and CPAP were more effective than lifestyle modification in improving clinical symptoms and polysomnographic parameters, although NIV yielded better respiratory functional improvements than did CPAP. Long-term studies must demonstrate whether this functional improvement has relevant implications. Clinical trial registered with www.clinicaltrials.gov (NCT01405976).

Patient acceptable symptom state and OMERACT–OARSI set of responder criteria in joint replacement. Identification of cut-off values

OBJECTIVE To identify new cut-off values beyond which patients can be considered as satisfied or as responders through patient acceptable symptom state (PASS) and OMERACT-OARSI (Outcome Measures in Rheumatology-Osteoarthritis Research Society International) set of responder criteria in total joint replacement. METHODS Secondary analysis of a 1-year prospective multicenter study of 861 patients, 510 with total knee replacement (TKR) and 351 with total hip prosthesis (THR). Pain and function data were collected by the reverse scoring option of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). PASS values were identified with the 25th centile estimation using an anchoring question about satisfaction with actual symptoms. OMERACT-OARSI set of responder criteria was based on a combination of absolute and relative change of pain, function and global patients assessment. Receiver operating characteristic (ROC) analysis was used as a complementary approach. RESULTS The values for PASS were about 80 and 69 for pain and function in THR, while these values were 80 and 68 when using OMERACT-OARSI criteria. Regarding TKR, PASS values were about 75 and 67 in pain and function with both criteria. ROC values were slightly lower in all cases. PASS and OMERACT-OARSI values varied moderately across tertiles of baseline severity. CONCLUSION With the provided data we can establish when a patient can be considered as satisfied/responder in joint replacement. The scores achieved at 1 year were very similar according to both criteria.

Is there much variation in variation? Revisiting statistics of small area variation in health services research

BackgroundThe importance of Small Area Variation Analysis for policy-making contrasts with the scarcity of work on the validity of the statistics used in these studies. Our study aims at 1) determining whether variation in utilization rates between health areas is higher than would be expected by chance, 2) estimating the statistical power of the variation statistics; and 3) evaluating the ability of different statistics to compare the variability among different procedures regardless of their rates.MethodsParametric bootstrap techniques were used to derive the empirical distribution for each statistic under the hypothesis of homogeneity across areas. Non-parametric procedures were used to analyze the empirical distribution for the observed statistics and compare the results in six situations (low/medium/high utilization rates and low/high variability). A small scale simulation study was conducted to assess the capacity of each statistic to discriminate between different scenarios with different degrees of variation.ResultsBootstrap techniques proved to be good at quantifying the difference between the null hypothesis and the variation observed in each situation, and to construct reliable tests and confidence intervals for each of the variation statistics analyzed. Although the good performance of Systematic Component of Variation (SCV), Empirical Bayes (EB) statistic shows better behaviour under the null hypothesis, it is able to detect variability if present, it is not influenced by the procedure rate and it is best able to discriminate between different degrees of heterogeneity.ConclusionThe EB statistics seems to be a good alternative to more conventional statistics used in small-area variation analysis in health service research because of its robustness.

Total knee replacement; minimal clinically important differences and responders

OBJECTIVE To provide new data on minimally clinical important difference (MCID) and percentages of responders on pain and functional dimensions of Western Ontario and McMaster Osteoarthritis Index (WOMAC) in patients who have undergone total knee replacement (TKR). METHODS 1-year prospective multicentre study with two different cohorts. Consecutive patients on the waiting list were recruited. There were 415 and 497 patients included. Pain and function were collected by the reverse scoring option of the WOMAC (0-100, worst to best). Transition items (five point scale) were collected at 1-year and MCID was calculated through mean change in patients somewhat better, Receiver Operating Characteristic (ROC) and two other questions about satisfaction. Analysis was performed in the whole sample and by tertiles of baseline severity. Likewise were calculated the percentages of patients who attained cut-off values. RESULTS Global MCID for pain were about 30 in both cohorts and 32 for. By ROC these values were about 20 and 24 respectively. According to the other two transitional questions these values were for pain 27 and 20 for function. By tertiles the worst the baseline score the higher the cut-off values. Percentage of responders does not change when comparing responders to the global MCID with their own tertile MCID and were about 61% for pain and 50% for function. CONCLUSION Due to the wide variations, MCID estimates should be calculated and used according to the baseline severity score.