Brief Report · Healthcare 2025, 13, 2541

The Greek Versions of the HLS₁₉ Health Literacy Instruments

Angeliki Flokou · Panagiotis Theodorou · Dimitris A. Niakas · Petros Kostagiolas

Ionian University, Dept. of Archives, Library Science & Museology, Corfu | Hellenic Open University, School of Social Sciences, Patra | National & Kapodistrian University of Athens, Medical School

healthcare Impact Factor 2.7 · MDPI Open Access · PubMed Indexed

https://doi.org/10.3390/healthcare13192541

01 · Background

Why health literacy matters — and why Greece needed these instruments

Health Literacy: Definition & Policy Context

WHO framework · HLS-EU · M-POHL

WHO definition: "The personal knowledge and competencies that accumulate through daily activities, social interactions, and across generations" — enabling access, understanding, appraisal, and use of health information.

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Consequences of low health literacy

Higher hospitalization & emergency use
Lower uptake of preventive care
Worse health status & higher mortality
Longer hospital stays & increased costs
Disproportionate burden on vulnerable groups

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Policy milestones

HLS-EU (2009–2012) — first cross-national benchmark; Greece participated
WHO Shanghai Declaration (2016) — HL central to SDG 2030
M-POHL (2018) — WHO Action Network for comparable HL data
HLS19 (2019–2021) — 17 countries; Greece did not participate

The gap: Despite growing political and scientific interest, Greece had no validated Greek versions of the HLS19 domain-specific instruments. This study addresses that gap.

The Three HLS19 Instruments

NAV · COM · VAC — domain-specific health literacy

HLS19-NAV-GR

Navigational HL

12 items across macro (system), meso (organizational), and micro (interpersonal) levels. Assesses ability to access, understand, appraise, and apply information to navigate the healthcare system.

HLS19-COM-GR

Communicative HL

11 items. Evaluates patients' communication and social skills when interacting with physicians — from describing symptoms to being involved in shared decision-making.

HLS19-VAC-GR

Vaccination HL

4 items. Captures perceived ability to find, understand, judge, and decide about vaccination-related information for oneself and family.

Common item stem & response scale

"On a scale from very easy to very difficult, how easy would you say it is…"

All items rated on a 4-point Likert scale: 1 Very Difficult 2 Difficult 3 Easy 4 Very Easy. Higher values = greater HL. Two scoring schemes: P-type (mean, 0–100) and D-type (% of Easy/Very Easy responses, 0–100).

02 · Methods

Translation, cultural adaptation & pilot field test

Adaptation & Field Testing Protocol

M-POHL guidelines · Dual forward/back-translation · N = 71

1

Permission — obtained from M-POHL / WHO Action Network (Dec 2024)

2

Dual forward translation — two independent translators, English → Greek; reconciled into single draft

3

Back-translation — third translator (blind), Greek → English; conceptual equivalence checked

4

Expert review — 11-member panel (healthcare professionals & academics); written comments compiled

5

Field test — N = 71, quota-guided telephone interviews; 4 NUTS-1 Greek regions

6

Test–retest — n = 16, ~12-day interval, ICC(2,1) as primary stability measure

Sample (N = 71)

Purposive, quota-guided non-probability sampling approximating Greek population by sex, age, education and geographic region (EL3 Attica · EL4 Aegean/Crete · EL5 Northern · EL6 Central Greece). Exceeds M-POHL minimum of >30.

Reliability analyses

Cronbach's α & ordinal α (polychoric/tetrachoric matrices); corrected item–total correlations (polyserial/point-biserial); mean inter-item correlations. Both polytomous (4-point) and dichotomous (0/1) coding examined.

Ethics: Research Ethics Committee, Ionian University (protocol [8813/8814/8815], 27 May 2025). GDPR-compliant; verbal informed consent.

Key Translation & Cultural Adaptations

NAV required most work · COM and VAC minimal changes

HLS19-NAV-GR — 6 issues resolved

NAV2, NAV3, NAV8: "to judge" → «να κρίνετε» / «να εκτιμήσετε» (context-dependent)
NAV2: Added clarifying examples (GP, specialist, hospital, health center)
NAV4: "ongoing reforms" → «µεταρρυθµίσεις υγείας που βρίσκονται σε εξέλιξη»
NAV12: "stand up for yourself" → «να υπερασπιστείτε τα δικαιώµατά σας» — aligned with Law 4368/2016 (patient rights offices)

HLS19-COM-GR & HLS19-VAC-GR

COM required no adjustments. VAC required one minor change:

VAC3: "to judge" → «να κρίνετε» (same solution as NAV)

The workflow proved its value: expert panel identified most issues; field test confirmed and revealed additional ones (NAV2 examples). Similar wording challenges noted in other HLS19 adaptations for appraisal verbs and broad system terms.

Completion times

~4 min

HLS19-NAV-GR
(range 2–9 min)

~3 min

HLS19-COM-GR
(range 2–8 min)

~1 min

HLS19-VAC-GR
(range 0.5–3 min)

03 · Results

Reliability, item distributions & scale scores

Test–Retest Stability & Internal Consistency

ICC(2,1) primary · Cronbach's α & ordinal α · N = 71, n = 16

0.91–0.93

ICC(2,1) across scales
"Excellent" (>0.90)

0.94–0.95

Ordinal α (polytomous)
All scales well above 0.70

0.92–0.94

Ordinal α (dichotomous)
Consistent across coding

Reliability summary by scale

Scale	Cronbach α (P)	Ordinal α (P)	Cronbach α (D)	Ordinal α (D)	ICC (2,1)
NAV-GR	0.94	0.95	0.89	0.94	0.91
COM-GR	0.91	0.94	0.84	0.93	0.93
VAC-GR	0.85	0.91	0.79	0.92	0.91

No item undermined reliability — "alpha if item deleted" showed no item whose removal would increase Cronbach's or ordinal α.

Notable exception: NAV8–NAV9 pair had the lowest inter-item correlation (0.08 dichotomous), suggesting different HL facets (scheduling/logistics vs. appraisal) rather than item failure.

Figure 1 — Item-level Response Distributions

Use tabs to switch scale · Hover/tap bars for details · Sort by Easy%

Item-level Highlights

Key patterns from Figure 1 — NAV · COM · VAC

NAV — balanced profile

Nearly symmetric 50/50 difficulty–ease split overall. NAV9 ("getting an appointment") easiest at 67.6% Easy+. NAV4 ("understanding healthcare reforms") hardest at 32.4% Easy+. Rank correlation with international HLS19 results: ρ = 0.73.

COM — generally easy, one outlier

Mean Easy+ = 72.7% — patients find communication relatively easy. COM1 ("describing reasons for consultation") highest at 90.1%. COM4 ("getting enough time") stands out at only 41%, reflecting Greece's short consultations (~10–15 min; 65% report insufficient time). ρ = 0.76 vs international.

VAC — ceiling effect

All 4 items show Easy+ > 70%. VAC2 ("understanding why vaccinations are needed") highest at 85.9%. This ceiling limits upper-range discrimination and responsiveness to change — future validation should consider harder items or expanded item pool.

APRP comparison: NAV (10–41–36–13%) closely matches Belgium (12–40–38–11%). COM (3–25–51–21%) resembles Germany (3–23–53–20%). VAC (1–21–46–32%) is similar to Norway (3–19–44–34%).

Figure 2 — Score Distributions: P-type & D-type

Switch scale with tabs · Histogram + aligned box plot · Hover bars for frequency

Scale-level Score Distributions

P-type & D-type · 0–100 · Descending order: VAC > COM > NAV

Descriptive statistics — P-type (polytomous) scoring

Scale	Mean	Median	SD	IQR	Skewness	Range
NAV-GR	51.1	50.0	21.1	25.0	+0.32	0–100
COM-GR	63.6	63.6	17.2	15.2	+0.14	15–100
VAC-GR	69.8	66.7	20.4	29.2	−0.12	33–100

Inter-scale correlations (Pearson r)

	HLS19-Q12-GR	NAV	COM
NAV	0.63	—	—
COM	0.52	0.64	—
VAC	0.58	0.47	0.59

All inter-scale correlations 0.40–0.70 — within the discriminant validity range; scales are related but measure distinct constructs.

P-type correlations with HLS19-Q12-GR match international averages (~0.60, 0.52, 0.60). D-type NAV and VAC also align closely with published country-level results.

Supplementary Table S7 — P-type → D-type Score Transitions (VAC)

Click/tap cells to highlight · Filter by transition type · 256 theoretical patterns

Discussion — Key Observations

NAV9 · COM4 · VAC ceiling · Methodological note

NAV9 — scheduling facet

"Understand how to get an appointment" showed lowest mean inter-item correlations but adequate item–total r. Consistent with cross-country HLS19-NAV evidence (8 countries): NAV9 repeatedly flagged for weaker fit and DIF, suggesting sensitivity to healthcare system context (access, scheduling) beyond individual HL skill.

COM4 — system-level barrier

"Get enough time in consultation" was the hardest COM item (41% Easy+). In Greece, consultations average 10–15 min; only 24% of patients with ≥2 chronic conditions receive >15 min (vs. OECD PaRIS average 47%). COM4 responses may partly reflect system capacity rather than communicative HL.

VAC ceiling effect

All VAC items cluster in Easy/Very Easy (71–86%). D-type VAC median = 100. This limits responsiveness to true improvements and discriminative ability at the upper end — consistent with HLS19 Consortium findings across 11 countries, who recommend harder items and an expanded item pool.

Methodological note

This is a translation, adaptation and field-testing study, not a full validation. N = 71 was designed for feasibility and item performance signals. Complete structural analyses (EFA/CFA, Rasch, DIF) are reserved for the upcoming national survey (N > 1000), excluding field-test participants.

Conclusions & Next Steps

The HLS19-NAV-GR, HLS19-COM-GR, and HLS19-VAC-GR are linguistically and culturally appropriate for the Greek population and operationally feasible (short completion times, minimal missing data).

High internal consistency (ordinal α 0.91–0.95) and excellent short-term stability (ICC 0.91–0.93) under both polytomous and dichotomous coding. No item undermined reliability.

Three priorities flagged for national validation: NAV9 (logistics facet), COM4 (system time constraints), VAC ceiling (need for harder items).

National validation study (N > 1000) is prepared: Rasch/PCM, CFA, measurement invariance, DIF testing — with potential to benchmark Greek population HL and monitor policy reforms.

Instruments can inform policy: navigation support programs, clinician communication training, vaccination literacy outreach, and lifelong learning for healthcare professionals.

The Greek Versions of the HLS19 Health Literacy Instruments