Measuring illness perceptions in the family context: psychometric properties of the IPQ-R adapted for adolescent-caregiver dyads

OBJECTIVES

Given the lack of validated measures assessing illness perceptions in families, the aim of our study was the development and psychometric testing of an adapted version of the Illness Perceptions Questionnaire-Revised (IPQ-R) allowing for Common Sense Model-based dyadic assessment of adolescents' and caregivers' perceptions of a chronic illness in adolescence.

METHODS

Using a cross-sectional survey design, factor structure, reliability and validity of the adapted measure You-IPQ-R were tested in a sample of adolescents with asthma (N = 155) and their primary caregivers (N = 132). Analysis included a dyadic methodology (dyadic confirmatory factor analyses) and examination of the suitability of the measure for different age groups.

RESULTS

Both the adolescent and the caregiver versions of the You-IPQ-R revealed good overall validity and reliability. For all Common Sense Model dimensions except for timeline cyclical in the caregiver version, unidimensional scales aligning with the original IPQ-R structure could be confirmed. Age-specific analyses revealed good to excellent measurement properties in adolescents aged 14 years or older, but considerably poorer indices in younger adolescents.

CONCLUSION

The dyadically validated You-IPQ-R will enable researchers and clinicians to compare illness perceptions in adolescent-caregiver dyads and to assess the effects of family illness perceptions' congruence upon medical, psychosocial and behavioural outcomes.

Treatment adherence in systemic sclerosis: A cross-sectional study

BACKGROUND

Treatment adherence is an important medical and pharmaco-economical phenomenon, influenced by multiple variables. Treatment adherence in systemic sclerosis (SSc) has been poorly studied.

OBJECTIVE

The aim of the present study was to assess treatment adherence in SSc patients and to identify factors associated with good and poor adherence.

METHODS

We conducted a monocentric, cross-sectional, observational study. Treatment adherence was evaluated by the Compliance Questionnaire of Rheumatology (CQR). The necessity of treatment and concerns about treatment were investigated using the Beliefs about Medicines Questionnaire-Specific (BMQ-S). The Illness Perception Questionnaire-Revised (IPQ-R) assessed illness perceptions. Disease-related characteristics were collected retrospectively.

RESULTS

A total of 66 patients were enrolled in this study. Of these, 47 (71.2%) had a weighted CQR score of ≤80% ("poor adherence") and 19 (28.8%) had a weighted CQR score of >80% ("good adherence"). No significant relationship between demographic, clinical or psychological factors and overall adherence could be found, except with the IPQ subscale "timeline acute/chronic" (p = 0.042). Our patient population estimated the necessity of their medication high (mean necessity score 20.5), with moderate concern beliefs (mean concern score 15.1). Subjective adherence, as self-reported by patients, was high.

CONCLUSIONS

This study demonstrated low treatment adherence rates in SSc patients. We could not identify demographic, clinical or psychological factors associated with treatment adherence, except with the IPQ subscale "timeline acute/chronic". This suggests a correlation between poor adherence and the belief that the disease will be chronic without improvement over time. Symptom relief was an important motivating factor for taking medication. The treatment necessity was scored higher than treatment concerns, but the necessity beliefs were not associated with adherence.

Disease Knowledge, Illness Perceptions, and Quality of Life in Adolescents With Sickle Cell Disease: Is There a Link?

Disease knowledge, illness perceptions, and quality of life (QOL) were examined in 150 adolescents (mean age = 16.1 years, SD = 1.9; 49.3% males) with sickle cell disease (SCD). Females had higher knowledge (P = .004), lower QOL (P = .02), and perceived their illness to be more unpredictable (P = .03). Those with more severe disease perceived their illness to be unpredictable with worse outcomes. Those with higher knowledge scores perceived their illness to be chronic, made more sense of their illness, and perceived greater personal and treatment control. Final hierarchical regression model showed that secondary education as compared to primary education level (P < .001) was positively correlated whereas disease severity (P < .001), perceived unpredictability (P = .024), and negative emotions (P < .001) were negatively correlated with QOL. Health practitioners should assess adolescents’ illness perceptions and encouraging continuing schooling and addressing emotional/psychological problems could improve their QOL.

Measuring illness representations in breast cancer survivors (BCS) prescribed tamoxifen: Modification and validation of the Revised Illness Perceptions Questionnaire (IPQ-BCS)

OBJECTIVE

The Revised Illness Perceptions Questionnaire (IPQ-R), widely used to assess illness perceptions, may fail to measure unique characteristics of different illnesses. This study modified and validated the IPQ-R for breast cancer survivors to provide detailed understanding of the specific illness perceptions held by these patients.

DESIGN

Initial modifications were made following qualitative interviews and were revised in a think-aloud study. The modified scale was tested in 753 breast cancer survivors prescribed tamoxifen. Modifications included adding a tamoxifen consequences scale and adapting the timeline scales to measure beliefs around risk of recurrence and cure. A confirmatory factor analysis was conducted on the modified questionnaire and an exploratory factor analysis on the causal beliefs scale. Test-retest reliability, internal consistency and construct validity were also examined.

RESULTS

The proposed eight-factor structure showed acceptable model fit, with high loadings and good reliability for all subscales. Correlations between subscales were consistent with theory and previous research.

CONCLUSIONS

The IPQ-BCS is valid and reliable, and provides unique understanding of specific perceptions held by this population, including beliefs surrounding risk of recurrence and consequences of ongoing hormonal treatment. Identifying these perceptions will aid development of interventions targeting depression, fear of recurrence and medication non-adherence.

Illness Representations of HIV Positive Patients Are Associated with Virologic Success

Introduction: It is important for HIV positive patients to be engaged in their care and be adherent to treatment in order to reduce disease progression and mortality. Studies found that illness representations influence adherence through the mediating role of coping behaviors. However, no study has ever tested if patient engagement to the visits mediate the relationship between illness perceptions and adherence. This study aimed to explore illness representations of HIV positive patients and test the hypothesis that illness representations predict adherence through the mediating role of a component of behavioral engagement. Methods: HIV-positive patients treated with highly active antiretroviral therapy (HAART) for at least one year and presenting to a check-up visit were eligible to participate in the study. Patients completed the Illness Perception Questionnaire-Revised. Behavioral engagement was measured based on the patients' clinical attendance to the check-up visits; adherence to HAART was measured by viral load. Undetectable viral load or HIV-RNA < 40 copies/ml were considered indexes of virologic success. Results: A total of 161 patients participated in the study. Most of them coherently attributed the experienced symptoms to HIV/HAART; perceived their condition as chronic, stable, coherent, judged the therapy as effective, and attributed their disease to the HIV virus and to their behavior or bad luck. The majority of patients (80.1%) regularly attended check-up visits and 88.5% of them reached virologic success. The mediation model did not show good fit indexes. However, a significant direct effect of two independent variables on virologic success was found. Specifically, the perception that the disease does not have serious consequences on patient's life and the prevalence of negative emotions toward HIV were associated with virologic success. On the contrary, the patient's perception that the disease has serious consequences on his/her life and the prevalence of positive emotions were associated with virologic failure. This model showed good fit indexes (CFI = 1; TLI = 1; RMSEA = 0.00; and WRMSR = 0.309). Discussion: Results do not support the mediating role of behavioral engagement in the relationship between illness representations and adherence. As perception of serious consequences coupled with positive emotions are directly associated with virologic failure, clinicians should take them into account to promote treatment adherence.

Psychometric evaluation of the revised Illness Perception Questionnaire (IPQ-R) in cancer patients: confirmatory factor analysis and Rasch analysis

OBJECTIVE

To provide new insights into the psychometrics of the revised Illness Perception Questionnaire (IPQ-R) in cancer patients. To undertake, for the first time using data from breast, colorectal and prostate cancer patients, a confirmatory factor analysis (CFA) to assess the validity of the IPQ-R's core seven-factor structure. Also, for the first time in any illness group, to undertake Rasch analysis to explore the extent to which the IPQ-R factors form unidimensional scales, with linear measurement properties and no Differential Item Functioning (DIF).

METHODS

Patients with potentially curable breast, colorectal or prostate cancer, within 6months post-diagnosis, completed the IPQ-R online (N=531). CFA was conducted, including multi-sample analysis, and for each IPQ-R factor fit to the Rasch model was assessed by examining, amongst other things, item fit, DIF and unidimensionality.

RESULTS

The CFA showed a moderate fit of the data to the IPQ-R model, and stability across diagnosis, although fit was significantly improved following the removal of selected items. All seven factors achieved fit to the Rasch model, and exhibited unidimensionality and minimal DIF, although in most cases this was after some item rescoring and/or deletion. In both analyses, IPQ-R items 12, 18 and 24 were indicated as misfitting and removed.

CONCLUSION

Given the rigorous standard of Rasch measurement, and the generic nature of the IPQ-R, it stood up well to the demands of the Rasch model in this study. Importantly, the results show that with some relatively minor, pragmatic modifications the IPQ-R could possess Rasch-standard measurement in cancer patients.

Physical and psychosocial factors associated with physical activity in patients with chronic obstructive pulmonary disease

OBJECTIVES

To assess physical activity and sitting time in patients with chronic obstructive pulmonary disease (COPD) and to investigate which physical and psychosocial factors are associated with physical activity and sitting time.

DESIGN

Cross-sectional study.

SETTING

Patients were recruited at outpatient clinics of general hospitals and from general practitioners.

PARTICIPANTS

Patients (N=113) with mild to very severe COPD.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Physical activity and sitting time were measured with a triaxial accelerometer (24h/d).

RESULTS

Mean locomotion time per 24 hours was 6.8% (range, 0.7%-20.4%). Elevated physical activity was independently associated with higher self-efficacy, higher functional exercise capacity, and lower lung hyperinflation. Decreased physical activity was strongest in more severe stages of COPD, in which the patients were mainly limited by physical disease-specific factors (higher lung hyperinflation, worse dyspnea severity, worse leg muscle function, and oxygen use). In less severe patients, physical activity was independently associated with more generic factors (higher self-efficacy and the spring/summer season). Sitting time did not differ between severity stages, and longer sitting time in the total group was independently associated with more positive perception of treatment control, less autonomous motivation to exercise, not using sleep medication, and oxygen use.

CONCLUSIONS

Both physical and psychosocial factors were associated with physical activity in patients with COPD. The factors associated with physical activity differed between disease severity stages, raising the question of whether physical activity enhancement programs should differ as well. Sitting time should be investigated further.