The influence of fear of symptoms and perceived control on asthma symptom perception

Internet-delivered cognitive-behaviour therapy for anxiety related to asthma: study protocol for a randomised controlled trial

INTRODUCTION

There is an established association between asthma and anxiety. The overlap between asthma symptoms and symptoms of anxiety may cause individuals to overestimate their asthma severity and restrict their daily activities leading to a low quality of life. There is currently weak evidence for treatments targeting anxiety related to asthma, but cognitive-behavioural therapy (CBT) has shown some promising but mixed results. The current randomised controlled trial will investigate if exposure-based internet-delivered CBT (Internet-CBT) is more effective than treatment as usual+medical education (TAU+ME) to relieve symptoms of anxiety and asthma control.

METHODS AND ANALYSIS

90 participants will be randomised 1:1 to 8 weeks of Internet-CBT or TAU+ME. The primary outcome, the patient-reported Catastrophising Asthma Scale, will be analysed from baseline to the primary endpoint at 16 weeks using hierarchical linear mixed model of the slope over time. Secondary outcomes, such as asthma control, quality of life and forced expiratory volume in 1 s, will be analysed correspondingly.

ETHICS AND DISSEMINATION

All participants will be informed about the study and leave their consent before study entry. All results will be analysed at group level and reported through publication in a peer-reviewed scientific journal within the field. The study received ethical approval by the Swedish Ethical Review Authority in January 2020 (ID: 2019-05985; 2022-01117-02).

TRIAL REGISTRATION NUMBER

Registered at ClinicalTrials.gov (ID: NCT04230369).

The effect of unpredictability on the perception of breathlessness: a narrative review

Breathlessness is an aversive bodily sensation impacting millions of people worldwide. It is often highly detrimental for patients and can lead to profound distress and suffering. Notably, unpredictable breathlessness episodes are often reported as being more severe and unpleasant than predictable episodes, but the underlying reasons have not yet been firmly established in experimental studies. This review aimed to summarize the available empirical evidence about the perception of unpredictable breathlessness in the adult population. Specifically, we examined: (1) effects of unpredictable relative to predictable episodes of breathlessness on their perceived intensity and unpleasantness, (2) potentially associated neural and psychophysiological correlates, (3) potentially related factors such as state and trait negative affectivity. Nine studies were identified and integrated in this review, all of them conducted in healthy adult participants. The main finding across studies suggested that unpredictable compared to predictable, breathlessness elicits more frequently states of high fear and distress, which may contribute to amplify the perception of unpredictable breathlessness, especially its unpleasantness. Trait negative affectivity did not seem to directly affect the perception of unpredictable breathlessness. However, it seemed to reinforce state fear and anxiety, hence possible indirect modulatory pathways through these affective states. Studies investigating neural correlates of breathlessness perception and psychophysiological measures did not show clear associations with unpredictability. We discuss the implication of these results for future research and clinical applications, which necessitate further investigations, especially in clinical samples suffering from breathlessness.

Symptom perceptions in functional disorders, major health conditions, and healthy controls: A general population study

Background

The present study investigated differences in symptom perceptions between individuals with functional disorders (FD), major health conditions, and FDs + major health conditions, respectively, and a group of healthy individuals. Furthermore, it investigated the relevance of FDs among other health-related and psychological correlates of symptom perceptions in the framework of the Common Sense Model of Self-Regulation (CMS).

Method

This cross-sectional study used epidemiological data from the Danish Study of Functional Disorders part two (N = 7,459 participants, 54% female, 51.99 ± 13.4 years). Symptom perceptions were assessed using the Brief Illness Perception Questionnaire (B-IPQ) and compared between the four health condition groups. Multiple regression analyses were performed to examine associations between symptom perceptions, FDs, and other health-related and psychological correlates from the CMS framework.

Results

Individuals with FDs (n = 976) and those with FDs + major health conditions (n = 162) reported less favorable symptom perceptions compared to the other two groups, particularly regarding perceived consequences, timeline, and emotional representations (effect size range Cohen’s d = 0.12-0.66). The presence of a FD was significantly associated with all B-IPQ items, even in the context of 16 other relevant health-related and psychological correlates from the CMS framework, whereas symptom presence last year or last week was not.

Conclusion

In the general population, symptom perceptions seem to play a more salient role in FD than in individuals with well-defined physical illness. Symptom perceptions should therefore be targeted in both primary and secondary interventions for FDs.

Poor respiratory health outcomes associated with high illness worry and alexithymia: Eleven-year prospective cohort study among the working-age population

OBJECTIVE

Poor respiratory health outcomes have been associated with poorer physical health and higher psychological distress. The aim of this study was to investigate whether illness worry, alexithymia or low sense of coherence predict i) the onset of new respiratory disease, ii) respiratory symptoms or iii) lung function among the working-age population, independently of comorbidity mood-, anxiety, or alcohol abuse disorders.

METHODS

The study was conducted among a nationally representative sample of the Finnish population (BRIF8901) aged 30-54 years (N = 2310) in 2000-2001 and was followed up in 2011. Individuals with a diagnosed respiratory disease or a severe psychiatric disorder at baseline were excluded. Lung function was measured by a spirometry test and psychiatric disorders were diagnosed using a structured clinical interview. Structured questionnaires were used to measure self-reported respiratory symptoms and diseases, illness worry, alexithymia, and sense of coherence.

RESULTS

High illness worry predicted an 11-year incidence of asthma (OR 1.47, 95% CI 1.09-1.99, p = 0.01). Alexithymia predicted shortness of breath (OR 1.32, 95% CI 1.13-1.53, p < 0.01) and 11-year incidence of COPD (OR 2.84, 95% CI 1.37-5.88, p < 0.01), even after several adjustments for physical and mental health. Psychological dispositions did not associate with lung function in 2011.

CONCLUSIONS

In the general population, psychological factors that modify health behaviour predicted adverse respiratory health outcomes independently of lung function after 11 years of follow-up. This indicates that considering them part of personalized treatment planning is important for promoting health-related behaviour among the working-age population.

Parent's self-reported indoor environment-related symptoms and health worry increase symptom reports among their children at school-Study in two independent populations

Little is known whether parent's indoor environment quality (IEQ)-related symptoms or health perceptions influence the risk of self- or parent-reported symptoms in their children. We assessed (i) the association of parents' IEQ-related symptoms with IEQ-related symptoms in their children at school and (ii) whether parental IEQ-related health worry increases the risk for children's symptoms. We used two Finnish studies: a national, population-based survey of indoor air and related health problems (n = 611 parents) and a subset of survey for all primary school pupils (grade 3-6) and their parents in Helsinki, which also included school IEQ-related symptoms reported by children (n = 1617 parent-child dyads). In the school survey, parent's own symptoms increased strongly their reporting of their children's symptoms at school (aOR 4.0, 95% CI 2.7-6.0 for parents experiencing a lot of symptoms) and also symptoms reported by the child itself (aOR 2.2, 95% CI 1.5-3.1). Similar, but slightly weaker associations were seen with parental IEQ-related health worries. Results remained unchanged when adjusted for the IEQ of school buildings or parental and children's allergic diseases. Similar associations were seen in the national survey between parent's symptoms at work and child's symptoms at school. The results suggest that parents' health perceptions may increase the reporting of children's IEQ-related symptoms even more than is typically seen for many indoor air contaminants.

Exposure-based cognitive behavior therapy for anxiety related to asthma: A feasibility study with multivariate baseline design

In the presence of asthma, the risk of having an anxiety disorder is increased twofold. The few trials conducted on cognitive behavior therapy (CBT) for anxiety and asthma have mainly targeted panic disorder, and with mixed results. Experimental laboratory research indicates that increased anxiety may lead to hypervigilance toward asthma. Hence, fear and avoidance associated with increased anxiety due to asthma may be an important treatment target. A treatment that learn participants to differentiate between anxiety and asthma through gradual exposure to situations that risk triggering anxiety for asthma may be a possible avenue. As a first step to investigate this issue further, we developed a 10-week exposure-based CBT protocol for anxiety related to asthma and tested it in six participants using multivariate baseline design with repeated assessments throughout treatment. All participants reported satisfaction with treatment, as well as subjective overall improvement after treatment. Visual analysis, using graphs over each individual's trajectory, as well as potential efficacy on group level analyzing standardized mean change, indicated improvements in important outcomes. We conclude that exposure-based CBT is feasible and may improve anxiety related to asthma. Further investigation under randomized controlled trial conditions is warranted.

The association of psychological factors and healthcare use with the discrepancy between subjective and objective respiratory-health complaints in the general population

BACKGROUND

We examined the prevalence of self-perceived respiratory symptoms (SRS) in the absence of any objective findings of respiratory pathology, and the association of such prevalence with psychological factors and healthcare use in the general population.

METHODS

The study was conducted among a nationally representative sample of Finnish adults (BRIF8901). Respiratory functioning was measured by a spirometry test. Structured questionnaires were used to measure SRS, physician visits and psychological factors of alexithymia, sense of coherence, illness worry and common mental disorders. Individuals with a diagnosed respiratory disease or a severe psychiatric disorder, determined in a diagnostic interview, were excluded, giving a sample comprising 4544 participants.

RESULTS

Twenty-six per cent of the general population and 36% of those with no diagnosed severe psychiatric disorder or respiratory disease experienced SRS despite a normal spirometry result. Psychological factors were associated with SRS (0.0001 &lt; p &lt; 0.032), and on the number of physician visit explaining 42.7% of the difference in visits between individuals with and without SRS, respectively. Illness worry was associated most strongly with SRS [odds ratio (OR) 1.29, 95% confidence interval (CI) 1.19-1.41, p &lt; 0.0001] and higher numbers of physician visits (OR 1.35, CI 1.32-1.38, p &lt; 0.00001), even after several adjustments.

CONCLUSIONS

Respiratory symptoms without objective findings are common in the general population. The study results underline the role of psychological factors in the reporting of respiratory symptoms and the associated medical burden, thereby indicating the functional nature of the symptomatology.

The mystery of dry indoor air - An overview

"Dry air" is a major and abundant indoor air quality complaint in office-like environments. The causality of perceived "dry air" and associated respiratory effects continues to be debated, despite no clear definition of the complaint, yet, has been provided. The perception of "dry air" is semantically confusing without an associated receptor but mimics a proto-state of sensory irritation like a cooling sensation. "Dry air" may also be confused with another common indoor air quality complaint "stuffy air", which mimics the sense of no fresh air and of nasal congestion. Low indoor air humidity (IAH) was dismissed more than four decades ago as cause of "dry air" complaints, rather indoor pollutants was proposed as possible exacerbating causative agents during the cold season. Many studies, however, have shown adverse effects of low IAH and beneficial effects of elevated IAH. In this literature overview, we try to answer, "What is perceived "dry air" in indoor environments and its associated causalities. Many studies have shown that the perception is caused not only by extended exposure to low IAH, but also simultaneously with and possibly exacerbated by indoor air pollutants that aggravate the protective mucous layer in the airways and the eye tear film. Immanent diseases in the nose and airways in the general population may also contribute to the overall complaint rate and including other risk factors like age of the population, use of medication, and external factors like the local ambient humidity. Low IAH may be the single cause of perceived "dry air" in the elderly population, while certain indoor air pollutants may come into play among susceptible people, in addition to baseline contribution of nasal diseases. Thus, perceived "dry air" intercorrelates with dry eyes and throat, certain indoor air pollutants, ambient humidity, low IAH, and nasal diseases.

Learning to Detect Triggers of Airway Symptoms: The Role of Illness Beliefs, Conceptual Categories and Actual Experience with Allergic Symptoms

Background: In asthma and allergic rhinitis, beliefs about what triggers allergic reactions often do not match objective allergy tests. This may be due to insensitivity for expectancy violations as a result of holding trigger beliefs based on conceptual relationships among triggers. In this laboratory experiment, we aimed to investigate how pre-existing beliefs and conceptual relationships among triggers interact with actual experience when learning differential symptom expectations.

Methods: Healthy participants (N = 48) received information that allergic reactions were a result of specific sensitivities versus general allergic vulnerability. Next, they performed a trigger learning task using a differential conditioning paradigm: brief inhalation of CO₂ enriched air was used to induce symptoms, while participants were led to believe that the symptoms came about as a result of inhaled allergens (conditioned stimuli, CS’s; CS+ followed by symptoms, CS- not followed by symptoms). CS+ and CS- stimuli either shared (e.g., birds-mammals) or did not share (e.g. birds-fungi) category membership. During Acquisition, participants reported symptom expectancy and symptom intensity for all triggers. During a Test 1 day later, participants rated symptom expectancies for old CS+/CS- triggers, for novel triggers within categories, and for exemplars of novel trigger categories. Data were analyzed using multilevel models.

Findings: Only a subgroup of participants (n = 22) showed differences between CO₂ and room air symptoms. In this group of responders, analysis of symptom expectancies during acquisition did not result in significant differential symptom CS+/CS- acquisition. A retention test 1 day later showed differential CS+/CS- symptom expectancies: When CS categories did not share category membership, specific sensitivity beliefs improved retention of CS+/CS- differentiation. However, when CS categories shared category membership, general vulnerability beliefs improved retention of CS+/CS- differentiation. Furthermore, participants showed some selectivity in generalization of symptom expectancies to novel categories, as symptom expectancies did not generalize to novel categories that were unrelated to CS+ or CS- categories. Generalization to novel categories was not affected by information about general vulnerability or specific sensitivities.

Discussion: Pre-existing vulnerability beliefs and conceptual relationships between trigger categories influence differential symptom expectancies to allergic triggers.

Effects by inhalation of abundant fragrances in indoor air - An overview

Odorous compounds (odors) like fragrances may cause adverse health effects. To assess their importance by inhalation, we have reviewed how the four major abundant and common airborne fragrances (α-pinene (APN), limonene (LIM), linalool (LIL), and eugenol (EUG)) impact the perceived indoor air quality as odor annoyance, sensory irritation and sensitization in the airways. Breathing and cardiovascular effects, and work performance, and the impact in the airways of ozone-initiated gas- and particle phase reactions products have also been assessed. Measured maximum indoor concentrations for APN, LIM and LIL are close to or above their odor thresholds, but far below their thresholds for sensory irritation in the eyes and upper airways; no information could be traced for EUG. Likewise, reported risk values for long-term effects are far above reported indoor concentrations. Human exposure studies with mixtures of APN and LIM and supported by animal inhalation models do not support sensitization of the airways at indoor levels by inhalation that include other selected fragrances. Human exposure studies, in general, indicate that reported lung function effects are likely due to the perception rather than toxic effects of the fragrances. In general, effects on the breathing rate and mood by exposure to the fragrances are inconclusive. The fragrances may increase the high-frequency heart rate variability, but aerosol exposure during cleaning activities may result in a reduction. Distractive effects influencing the work performance by fragrance/odor exposure are consistently reported, but their persistence over time is unknown. Mice inhalation studies indicate that LIM or its reaction mixture may possess anti-inflammatory properties. There is insufficient information that ozone-initiated reactions with APN or LIM at typical indoor levels cause airway effects in humans. Limited experimental information is available on long-term effects of ozone-initiated reaction products of APN and LIM at typical indoor levels.

Symptoms, lung function, and perception of asthma control: an exploration into the heterogeneity of the asthma control construct

BACKGROUND

Asthma control is still surprisingly poor, which may be related to factors causing discrepancies between objective lung function measures and subjective symptom reports or discrepancies between objective indicators of asthma control and control perception. Identifying patients prone to such discrepancies may help to understand asthma control problems.

METHODS

Ninety-four persons with asthma participated in this study. We used cluster analysis to identify different subgroups of asthma control, based on a measure of lung function and self-report of daytime and nighttime symptoms, activity limitations, reliever medication use, and perception of asthma control. Subsequently, we explored between-cluster differences in clinical and psychological characteristics.

RESULTS

We identified two homogeneous clusters: a cluster of persons with poorly controlled asthma and a cluster of persons with well-controlled asthma. A third cluster included persons with an intermediate level of asthma control, an absence of nighttime symptoms, and a reduced impact of asthma symptoms on daily activities despite high levels of symptoms and reliever medication use. Members of the poorly controlled asthma cluster showed higher symptom levels, more catastrophic thinking, and activity avoidance beliefs compared with members of other clusters.

CONCLUSION

The clusters we identified crosscut current definitions of asthma severity and asthma control and indicate the importance of affective evaluation of symptoms in explaining poor asthma control.