Global Influenza Seasonality: Reconciling Patterns across Temperate and Tropical Regions

Bac k g r o u n d: Despite the significant disease burden of the influenza virus in humans, our understanding of the basis for its pronounced seasonality remains incomplete. Past observations that influenza epidemics occur in the winter across temperate climates, combined with insufficient knowledge about the epidemiology of influenza in the tropics, led to the perception that cool and dry conditions were a necessary, and possibly sufficient, driver of influenza epidemics. Recent reports of substantial levels of influenza virus activity and well-defined seasonality in tropical regions, where warm and humid conditions often persist year-round, have rendered previous hypotheses insufficient for explaining global patterns of influenza. Objectiv e: In this review, we examined the scientific evidence for the seasonal mechanisms that potentially explain the complex seasonal patterns of influenza disease activity observed globally. Me t h o d s: In this review we assessed the strength of a range of hypotheses that attempt to explain observations of influenza seasonality across different latitudes and how they relate to each other. We reviewed studies describing population-scale observations, mathematical models, and ecological, laboratory, and clinical experiments pertaining to influenza seasonality. The literature review includes studies that directly mention the topic of influenza seasonality, as well as other topics w

Spousal involvement and CPAP adherence: A dyadic perspective

Poor adherence to continuous positive airway pressure (CPAP) treatment is associated with substantial health care costs, morbidity and mortality, and has been a leading obstacle in the effective management of obstructive sleep apnea (OSA). Successful interventions to improve CPAP adherence may ultimately include a variety of components. For patients living with spouses (refers to all domestic partners), the spouse will likely be an integral component to any successful intervention. Developing understanding of the role of spouses in adherence to CPAP has been identified to be a critical research need. This review expands the investigation of CPAP adherence to a broader context, from an exclusive focus on individual patients to a dyadic perspective encompassing both patients and their spouses. A conceptual framework based on social support and social control theories is proposed to understand spousal involvement in CPAP adherence. Methodologies for future investigations are discussed, along with implications for developing interventions that engage both patients and their spouses to improve CPAP use

The Association of Age, Insomnia, and Self-Efficacy with Continuous Positive Airway Pressure Adherence in Black, White, and Hispanic US Veterans

STUDY OBJECTIVES: Studies of continuous positive airway pressure (CPAP) adherence in multi-ethnic samples are lacking. This study explores previously described factors associated with therapeutic CPAP use in South Florida veterans with obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: We performed a retrospective, cross-sectional analysis of CPAP adherence comparing white, black, and Hispanic veterans returning to the Miami VA sleep clinic over a 4-month period. Participants had CPAP use download and completed questionnaires on demographics, sleepiness, insomnia, and social cognitive measures related to adherence. Linear regression modeling was used to explore the impact of measured variables and potential interactions with race-ethnicity on mean daily CPAP use. RESULTS: Participants (N = 248) were 94% male with mean age of 59 ± 11 years and included 95 blacks (38%), 91 whites (37%), and 62 Hispanic (25%) veterans. Blacks had less mean daily CPAP use than whites (-1.6 h, p < 0.001) and Hispanics (-1.3 h, p < 0.01). Blacks reported worse sleep onset insomnia symptoms compared to whites. In the final multivariable regression model, black race-ethnicity (p < 0.01), insomnia symptoms (p < 0.001), and self-efficacy (p < 0.001) were significantly associated with mean daily CPAP use. In addition, the black race by age interaction term showed a trend towards significance (p = 0.10). CONCLUSIONS: In agreement with recent studies, we found that mean daily CPAP use in blacks was 1 hour less than whites after adjusting for covariates. No CPAP adherence differences were noted between whites and Hispanics. Further investigations exploring sociocultural barriers to regular CPAP use in minority individuals with OSAHS are needed. CITATION: Wallace DM; Shafazand S; Aloia MS; Wohlgemuth WK. The association of age, insomnia, and self-efficacy with continuous positive airway pressure adherence in black, white, and Hispanic US veterans. J Clin Sleep Med 2013;9(9):885-895

Motivational enhancement to improve adherence to positive airway pressure in patients with obstructive sleep apnea: A randomized controlled trial

BACKGROUND: Obstructive sleep apnea (OSA) is associated with a variety of medical conditions. Positive airway pressure (PAP) is an effective treatment for improving sleep, yet adherence rates are low. The aim of the current study is to test two treatments versus standard care in improving adherence to PAP. METHOD: Two hundred twenty-seven patients with OSA were randomized to standard care (SC), education (ED) and motivational enhancement therapy (MET). Adherence was measured objectively and the first week of adherence (prior to the intervention) was used as an a priori moderator of the effect of the various interventions. Mediators of treatment response were also examined using theory-based measures of decisional balance and self-efficacy. RESULTS: Adherence declined over time for all three groups. There was a significant interaction between level of adherence during the first week of treatment and treatment group. Those who had moderate levels of adherence during their first week of PAP were more likely to adhere to treatment at follow-up if they had MET; those who had high levels of adherence during their first week of PAP were more likely to adhere to treatment at follow-up if they had ED. MET treatment increased the perception of the positive aspects of PAP, but ED did not. CONCLUSIONS: Initial adherence to positive airway pressure could help guide subsequent treatment plans. The results also support social cognitive theory in that educational approaches might be best suited for those who are ready for change whereas more motivational approaches might be best for those who are ambivalent about change. CITATION: Aloia MS; Arnedt JT; Strand M; Millman RP; Borrelli B. Motivational enhancement to improve adherence to positive airway pressure in patients with obstructive sleep apnea: a randomized controlled trial. SLEEP 2013;36(11):1655-1662

A latent-class heteroskedastic hurdle trajectory model: patterns of adherence in obstructive sleep apnea patients on CPAP therapy

Background: Sleep apnea patients on CPAP therapy exhibit differences in how they adhere to the therapy. Previous studies have demonstrated the benefit of describing adherence in terms of discernible longitudinal patterns. However, these analyses have been done on a limited number of patients, and did not properly represent the temporal characteristics and heterogeneity of adherence. Methods: We illustrate the potential of identifying patterns of adherence with a latent-class heteroskedastic hurdle trajectory approach using generalized additive modeling. The model represents the adherence trajectories on three aspects over time: the daily hurdle of using the therapy, the daily time spent on therapy, and the day-to-day variability. The combination of these three characteristics has not been studied before. Results: Applying the proposed model to a dataset of 10,000 patients in their first three months of therapy resulted in nine adherence groups, among which 49% of patients exhibited a change in adherence over time. The identified group trajectories revealed a non-linear association between the change in the daily hurdle of using the therapy, and the average time on therapy. The largest difference between groups was observed in the patient motivation score. The adherence patterns were also associated with different levels of high residual AHI, and day-to-day variability in leakage. Conclusion: The inclusion of the hurdle model and the heteroskedastic model into the mixture model enabled the discovery of additional adherence patterns, and a more descriptive representation of patient behavior over time. Therapy adherence was mostly affected by a lack of attempts over time, suggesting that encouraging these patients to attempt therapy on a daily basis, irrespective of the number of hours used, could drive adherence. We believe the methodology is applicable to other domains of therapy or medication adherence

A latent-class heteroskedastic hurdle trajectory model: patterns of adherence in obstructive sleep apnea patients on CPAP therapy

Background Sleep apnea patients on CPAP therapy exhibit differences in how they adhere to the therapy. Previous studies have demonstrated the benefit of describing adherence in terms of discernible longitudinal patterns. However, these analyses have been done on a limited number of patients, and did not properly represent the temporal characteristics and heterogeneity of adherence. Methods We illustrate the potential of identifying patterns of adherence with a latent-class heteroskedastic hurdle trajectory approach using generalized additive modeling. The model represents the adherence trajectories on three aspects over time: the daily hurdle of using the therapy, the daily time spent on therapy, and the day-to-day variability. The combination of these three characteristics has not been studied before. Results Applying the proposed model to a dataset of 10,000 patients in their first three months of therapy resulted in nine adherence groups, among which 49% of patients exhibited a change in adherence over time. The identified group trajectories revealed a non-linear association between the change in the daily hurdle of using the therapy, and the average time on therapy. The largest difference between groups was observed in the patient motivation score. The adherence patterns were also associated with different levels of high residual AHI, and day-to-day variability in leakage. Conclusion The inclusion of the hurdle model and the heteroskedastic model into the mixture model enabled the discovery of additional adherence patterns, and a more descriptive representation of patient behavior over time. Therapy adherence was mostly affected by a lack of attempts over time, suggesting that encouraging these patients to attempt therapy on a daily basis, irrespective of the number of hours used, could drive adherence. We believe the methodology is applicable to other domains of therapy or medication adherence