The aim of this secondary analysis was to establish the discrimination and responsiveness of two generic PREMs (The Australian Hospital Patient Experience Question Set (AHPEQS) [14]; the Functional Assessment of Chronic Illness Therapy (Treatment Satisfaction - General) (FACIT-TS-G) [15]), and one generic HRQoL measure (EuroQol Five Dimension, Five Level (EQ5D-5L) [16]), collected as an outcome of a recent clinical trial comparing two PIVC designs (integrated, non-integrated) [17]. Prior to this study, none of the selected instruments (EQ5D-5L, FACIT-TS-G, or AHPEQS) had previously been used to assess health-related outcomes for patients with PIVCs.

Hypotheses

1 A: Null Hypothesis (discrimination). There will be no significant difference in the experiences of participants observed with desirable (completion of therapy) or undesirable (device failure) outcomes using the Functional Assessment of Chronic Illness Therapy (FACIT, PREM), or the Australian Hospital Patient Experience Question Set (AHPEQS, PREM).

1B: Null Hypothesis (responsiveness): There will be no significant difference in the quality of life outcomes of participants observed with desirable (completion of therapy) or undesirable (device failure) outcomes using the EQ5D-5L (HRQoL).

Data collection

A multi-site randomised controlled trial (RCT) comparing the use of integrated- and non-integrated PIVCs, the OPTIMUM Trial (Australian New Zealand Clinical Trials Registry, ACTRN12617000089336) [17], was conducted between July 2017 and December 2019. In total, 1,759 adult participants were recruited from medical, surgical, and emergency settings across three adult tertiary acute care hospitals [17]. Research Nurses prospectively recruited participants prior to PIVC insertion, subsequently collecting data on patient demographics (e.g., gender, age, underlying condition), and device details (e.g., number of insertion attempts, inserting clinician, device location). Participants were assessed daily for signs and symptoms of site complications (e.g., pain, erythema/redness). Upon PIVC removal, device outcome data (e.g., reason for removal, signs, and symptoms of site complications) and patient outcome data (e.g., treatment received, PIVC replacement) were collected.

Concurrently, a convenience sample of patients (n = 685) were approached across two recruiting sites to provide responses to a HRQoL survey, (EQ5D-5L) and one of two patient experience surveys (FACIT-TS-G and AHPEQS). Sampling occurred Monday to Friday, based on availability of the Research Nurse. Participants were invited to participate if they were able to provide verbal informed consent and were expected to require the PIVC for > 48 h. The EQ5D-5L was administered at baseline (prior to or immediately following PIVC insertion) and at 36 to 60 h following PIVC insertion (reliant upon participant availability). The FACIT-TS-G (available for collection between July 2017 and December 2018) and AHPEQS (available between January 2019 and December 2019) were also administered at 36 to 60 h following PIVC insertion. The follow-up time-point (i.e., 36 to 60 h) was selected a-priori, based on the expected mean dwell time of PIVCs (local average dwell time between 1.5 and 2.5 days) [3, 18] to ensure a higher response rate (minimising attrition related to patients discharged immediately following PIVC removal). Notably, while two instruments (EQ5D-5L and FACIT-TS-G) were administered with an introductory statement asking the patient to relate responses to their outcome and experiences associated with their PIVC, one (AHPEQS) was not. This tool was instead administered with respect to the patient’s (whole) hospital experience.

Instruments

Henceforth, all individual questions within the instruments will be referred to as ‘items’ and values recorded from responses on item scales will be ‘scores.’

Equation 5D-5 L

HRQoL was assessed using the EQ5D-5L [16]; this measure was selected for use in the multi-site RCT through investigator consensus, based on the widespread use of the tool and selection for use in other venous access device trials. First published in 1991 as a three-level generic measure (later adopted to a five-level option in 2009), the EQ5D is one of the most widely used quality of life instruments worldwide [19]. It has been validated in many clinical contexts (e.g., orthopaedic, cardiac settings) [20, 21], and is available in more than 150 languages [16]. The EQ5D-5L consists of five domains (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) measured against 5-levels (ranging from no problems to extreme problems) with a supplementary visual analogue scale for a self-reported health status measure (0 to 100; worst to best health). The instrument is intended for a patient population of ≥ 16 years of age and takes only a few minutes to complete [16]. EQ5D-5L responses are scored to determine a ‘summary index value’ (continuous variable, henceforth ‘utility’) as per the Australian EQ5D-5L algorithm, which accounts for up to 243 different health states (1.0, perfect health to -0.217, worse than death) [22, 23]. A disutility index value was also created by subtracting the utility estimate from one (perfect health). The introduction statement is available in Supplementary File 1.

FACIT-TS-G

The Functional Assessment of Chronic Illness Therapy (FACIT) measurement questionnaires, established by FACIT.org, are a series of measurements, established in over 80 languages, to assess HRQoL for a number of specific (e.g., cancer/treatment-specific) and general conditions [15]. No PIVC-specific FACIT measurement currently exists. The Functional Assessment of Chronic Illness Therapy – Treatment Satisfaction – General measure (FACIT-TS-G) was selected as the most appropriate generic PREM instrument to pilot-test in this context, intended for a population of ≥ 18 years or age undergoing treatment for chronic illness. This tool was selected by consensus of the investigator team, based on appropriateness of the included items. While the multi-centre RCT included general medical and surgical in-patients, this experience measure (designed for patients with chronic illness) was selected based on known patient demographics at the participating hospitals (which demonstrated high rates of re-admissions and underlying multi-morbidity).The tool is comprised of eight unique items which can be collated for a single summary score and is estimated to require 5 min for completion [15]. The introduction statement is available in Supplementary File 1.

AHPEQS

Following the rigorous development and subsequent release of the AHPEQS, developed by the Australian Commission on Safety and Quality in Health Care in 2017, use of the FACIT-TS-G was ceased, and replaced, following investigator consensus. The AHPEQS is a PREM instrument consisting of ten core items (and two sub-items) intended for use by hospitals and other healthcare providers to survey patients on their recent experiences of treatment/care [14]. The instrument is designed for a population of ≥ 18 years of age and takes approximately 10 min to complete. The introduction statement is available in Supplementary File 1.

Outcomes of interest

The performance of the three unique instruments were assessed against two key outcomes of interest, collected during the conduct of the large multi-centre RCT. These included:

1.

All-cause PIVC failure: binary variable, a composite measure of failure resulting from the most commonly occurring PIVC complications, including occlusion (the inability to infuse IV medications/fluids) [17], infiltration (movement of intravenous fluid/medication outside of the vein into the patient’s cell tissue), cell damage from an irritant infusate (extravasation) [17], phlebitis defined as clinician-reported phlebitis; patient-reported pain/tenderness (≥ 2 on a 0–10 scale) resulting in PIVC removal, or two or more of pain/tenderness (≥ 1 on a 0–10 scale), erythema (redness), swelling, palpable cord, vein streak, or purulent drainage) [17] (up to 24 h prior to PIVC removal), dislodgement [17], and local/bloodstream infection (according to the Centers for Disease Control/National Health and Safety Network definitions) [24].

2.

Multiple insertion attempt: binary variable, defined as a PIVC requiring more than a single attempt (needle to skin) for successful insertion [17].

Data analysis

Analysis methods were informed by previous studies, which similarly analysed generic HRQoL measures in various clinical contexts [25, 26]. Data were imported into Stata (StataCorp, Release 13. College Station, TX: StataCorp LLC) to analyse the three unique instruments’ discrimination, responsiveness, and ceiling/floor effects. P-values less than 0.05 were considered statistically significant. No formal corrections for multiple comparisons were applied. No data were imputed; where missing data exists, altered sample sizes are provided.

Discrimination

(used to measure construct validity), is defined as the ability for the instruments to accurately discriminate between clinical severity levels [25] (in this case, the relationship between patient-reported scores; and PIVC failure- and non-failure events (e.g., multiple insertion attempts versus single attempt). This was analysed using generalised linear regression (gamma) model (Eq. 5D-5 L disutility scores only), regression model (ordinary least squares), ordered logistic regression model, or multinomial (polytomous) logistic regression model [27]. All regression models were multivariable, adjusting for clinically important patient/PIVC characteristics (hospital, age, gender, medical/surgical admission, PIVC type (integrated or non-integrated), device location, and gauge size).

Responsiveness

Three statistics were used to assess responsiveness (the absolute value of change over time, in direction and magnitude) [28] of EQ5D-5L (only); this included (i) ES (calculated as the mean EQ5D-5L score change (D) divided by standard deviation (SD) at baseline), (ii) standardised response mean (SRM) (calculated as D divided by SD of score changes), and (iii) the responsiveness statistic (calculated as D divided by SD of the constant (unchanged responses, stable participant) D) [29]. Responsiveness ES was compared against standard thresholds (< 0.2, ‘trivial’; ≥0.2 but < 0.50, ‘small’; ≥0.5 but < 0.80, ‘moderate;’ ≥0.8, ‘large’) [30].

Ceiling and floor effects

Assessed for all instruments (EQ5D-5L, FACIT-TS-G, AHPEQS), these were measured to test whether the instruments had the ability to represent the construct being assessed by preventing the identification of a possible genuine difference [31]. Established a-priori, we determined there to be a ceiling effect when ≥ 80% of responses selected the highest score of the item and a floor effect when ≥ 80% of responses select the lowest score of the item.