This was a mixed-method multicenter study conducted in 6 organizations in the Czech Republic (3 hospices and 3 hospitals). Data were obtained by trained staff - nurses or social workers during the hospitalization. The inclusion criteria were: being patient of hospice or palliative care team/unit in the hospital and able to give consent to participate. We excluded patients who had cognitive impairment and who did not understand the Czech language. Patients completed IPOS and a demographic questionnaire on their own or with help from the staff member. When appropriate, patients were asked to complete IPOS twice during the hospitalization for testing of reliability.
IPOS consists of 10 questions with 17 items. Question 1 is about the main concerns and has open-ended options. Q2 addresses specific symptoms and there is also a place for adding any additional symptoms (Q2a-c). Q3-Q6 ask about psychological, spiritual, communication and practical concerns but Q6-8 address positive aspects and the direction of possible answers is opposite. Q10 is not scored and asks patients whether they filled IPOS with any help or by themselves. All questions except Q1 have a numerical scale from 0 to 4 and only one response is allowed for each question. The sum score can range from 0 to 68 and is computed from all items except Q1 and Q2a-c.
Czech version was created clarifying conceptual definition equivalents in Czech followed by forward and backward translation which was done by independent translators as required by the Manual for the cross-cultural adaptation of the POS (19). The initial Czech version of IPOS was piloted through cognitive interviews with 5 patients and 5 health care providers from hospice and the face validity of the Czech IPOS was confirmed. The final Czech version of IPOS can be found in Appendix 1.
Part of the sample completed the Edmonton Symptom Assessment System or Palliative Performance scale for testing the construct validity of IPOS. Edmonton Symptom Assessment System (ESAS) is another questionnaire assessing the quality of life and is commonly used in Czech hospices. ESAS consists of 10 physical and psychical symptoms and patients are asked to rate the symptoms severity from 0 to 10 on a numerical scale (20).
Palliative Performance Scale (PPS) is a tool for measuring performance status of patients in palliative care and it is usually recorded by nurses or by physicians with good inter-rater agreement (21). It was developed from the Karnofsky Performance Scale (22). It is oriented on physical symptoms and can be used for prognostication and planning care (23). Patients' performance is scored by percentage in 11 categories from fully ambulatory and healthy (100%) to death (0%). The ratings are based on observation of 5 categories: ambulation, level of activity and evidence of disease, ability to self-care, food/fluid intake and state of consciousness (22).
The Ethical Committee of the General University Hospital in Prague approved the study (Protocol Number 51/18 S-IV).
Statistical Analysis
Internal consistency of the IPOS total score was investigated by using Cronbach ‘s alfa. Part of the sample (13%) completed the IPOS in two different times (T1 and T2) with an average range of 15.6 days between the measures (SD = 9.0). Test-retest reliability of the IPOS total score was evaluated using the intraclass correlation coefficient (ICC). An ICC range of 0.4–0.7 was considered moderate and > 0.7 was considered to represent high test-retest reliability. For each of 17 IPOS items, we also computed four metrics of test-retest reliability: level of agreement, level of agreement within one score, quadratic weighted kappa and Spearman correlation. A range of kappa from 0.41 to 0.60 was considered as moderate, 0.61–0.80 as substantial, and 0.81–1 as almost perfect (24,25).
To test the influence of gender, place of care and age, we used parametric methods (t-test and Pearson correlation coefficient respectively) based on a sufficiently large sample and normal distribution of overall IPOS score.
Moreover, we used factor analysis to explore the possible dimensions of the Czech IPOS questionnaire and to assess its construct validity. We applied Exploratory factor analysis (EFA) using principal axis factoring as the extraction method and Varimax rotations. The number of factors to be extracted derived from the combination of Kaiser's criterion and Cattell's scree plot method.
The Spearman correlations between the IPOS score and two other measures commonly used in palliative care (ESAS and PPS) were assessed to report preliminary results of convergent validity. The non-parametric method was chosen due to quite small sample sizes.
All missing values were excluded from the analysis. A significant p-value was set at 0.05. All analyses were conducted within SPSS v. 25.0 (IBM Corp., Armonk, NY, USA).