M16 Construct validity of the needs assessment tool progressive diseases for interstitial lung disease (NAT: PD-ILD) patients

Abstract

Background: People with non-cancer conditions have unmet palliative care needs. All clinicians need to be able to identify, manage, and refer to specialist palliative care (SPC) services as needed. People with interstitial lung disease (ILD) currently have less access to SPC and there is no Needs Assessment Tool (NAT) designed for clinical use. We adapted the NAT: Progressive Diseases (PD)-cancer for use in ILD and conducted psychometric testing. Aim: To test the construct validity of NAT: PD-ILD. Methods: ILD clinicians in four ILD hospital clinic sites were trained to use the NAT: PD-ILD. After a consultation the clinician completed the NAT: PD-ILD, patients completed the St. George's Respiratory Questionnaire (SGRQ-I) and carers completed the Carer Strain Index (CSI) and Carer Support Needs Assessment Tool (CSNAT). Kendall's Tau-b correlation coefficient (and associated p-value) was calculated to determine the correlation between the NAT: PD-ILD items relating to patient well-being, and a total score for a subset of SGRQ-I questions identified a priori as measuring similar constructs. The prevalence and bias-adjusted kappa (PABAK), Cohen's kappa, and percentage of agreement were used to assess whether responses were similar between the NAT: PD-ILD items relating to the ability and well-being of the carer and appropriate CSI and CSNAT items which were considered to measure similar concerns/support needs. Results: A total of 68 patients were recruited (site 1 n = 39; site 2 n = 17; site 3 n = 9; site 4 n = 3). The average age of participating patients was 66 years (range, 34-87 years) and 62% were male (n = 42). A total of 45 (66%) patients had a carer (spouses = 82%, child = 11%, other relative = 4%, friend/neighbor = 2%) of whom 27 completed the CSI (mean 4.4, standard deviation (SD) 3.0, median 4 range 0-11) and 29 completed at least one item of the CSNAT. Items 2, 3, 5, and 6 of the NAT: PD-ILD statistically significantly positively correlated with their comparator SGRQ-I scores (ρ range 0.24-0.36, p < 0.05). PABAK values comparing the NAT: PD-ILD items with appropriate CSI and CSNAT items show most items have PABAKpositive values (range from 0.04 to 0.57, with a minimum of 52% agreement). However, NAT: PD-ILD items 11 and 13 have negative PABAK values (inter-personal relationships and Grief topics-Psychosocial Dimension). Conclusion: The NAT: PD-ILD has adequate construct validity for most domains. However, agreement is poor for physical symptoms and spiritual concerns. This may indicate that clinicians identify concerns with symptoms less well unless they are severe enough to cause difficulties with activities of daily living or functional ability; training may be needed to help them assess patient symptoms at an earlier stage. In the caregivers section, there was agreement except for two, where again, this may indicate clinician training needs.