Comparing patient‑reported outcome and experience measures in international health surveys

2. Comparing methodologies of five international surveys

Over the past decade, international health surveys have converged towards the use of common, standardised and validated PROMs and PREMs. For example, PaRIS integrates PROMIS® Global Health items including pain and fatigue, the WHO‑5 Well-being Index, and P3CEQ, while EHIS employs WHO‑5 and PHQ‑8, and the IHP survey includes selected PROMIS pain and fatigue items. While the instruments used across these surveys may appear similar at first glance, important differences in the projects’ scope, purpose and methodological choices can lead to divergent results that require careful interpretation. This section outlines the characteristics of PaRIS, EHIS, the IHP survey, PVS and SHARE and makes comparisons of their purposes, scopes and methods.

This section provides a structured comparison of PaRIS with EHIS, the IHP survey, PVS and SHARE, highlighting key design features and methodological choices. Differences in survey objectives, target populations, sampling strategies, data collection modes and analytical frameworks shape the type of insights these surveys can generate and the policy questions they can answer. By clarifying where approaches converge and where they diverge, the section lays the groundwork for subsequent analyses of overlapping indicators and supports policymakers in selecting the most appropriate data source for their specific policy questions.

2.1. While all surveys share the overarching goal of improving health systems, each focusses on distinct dimensions for assessment

While each of these surveys aims to provide policymakers and other stakeholders with actionable, comparable evidence on how well healthcare systems deliver for people, each survey uses different assessment parameters.

• PaRIS is designed to assess primary care performance for people living with chronic conditions by linking outcomes and experiences to practice and system-level features that can be strengthened through international benchmarking and cross-country learning.

• EHIS supports public health and health system monitoring across EU countries by describing population health status, determinants, and healthcare use to guide prevention strategies, resource allocation, and equity-focussed policies.

• The IHP survey aims to benchmark access, affordability, care co‑ordination, patient experience and system responsiveness across several countries, helping decision makers identify reform priorities and learn from peer systems.

• PVS focusses on measuring utilisation, care quality, system competence, and population confidence in the health system to enhance accountability.

• SHARE primarily informs ageing and social policy by tracking the health, functional status, economic security and care needs of older populations over time, supporting decisions on long-term care, pensions, workforce participation and the sustainability of health and social systems.

Taken together, these differences in purpose highlight that the surveys are largely complementary rather than redundant, and that combining evidence across initiatives is often necessary to support policy-relevant insights.

The distinct but complementary purposes of these surveys make them mutually reinforcing (Box 1). While population-based surveys reveal who is at risk, patient surveys assess how healthcare performs from the perspective of its users. PaRIS focusses on collecting harmonised PROMs and PREMs from primary care users and their practices, with an explicit emphasis on international comparability and policy relevance regarding chronic care across Member and Partner countries. EHIS is a European Union (EU)–wide household survey designed to monitor population health status, health determinants and healthcare use. The IHP survey provides regular, cross-country insights into health system performance and patient experiences, primarily through population-based surveys. PVS offers a globally applicable framework for capturing health system experiences, including in low- and middle‑income settings. SHARE is a longitudinal study in Europe focussing on ageing among older populations, together with health and socio‑economic conditions.

Box 1. Key features of the surveys

PaRIS, EHIS, the IHP survey, PVS, and SHARE differ substantially in governance, coverage and methodological scope, which is important for interpreting results across the report.

PaRIS is co‑ordinated by the OECD on a voluntary basis. Cycle 1 covered 19 OECD Member and partner countries, focussing specifically on primary care users aged 45 and over with recent contact, using a cross‑sectional, two‑stage sampling design anchored in primary care practices, and primarily online data collection with mixed-method supplementation.

EHIS is co‑ordinated by Eurostat and mandatory under EU regulation. The last round covered all 27 EU Member States and surveyed the general population aged 15 and over in private households using harmonised, multi‑stage household samples and predominantly face‑to‑face interviews.

The Commonwealth Fund’s IHP survey targets adults aged 65 and over in selected countries, employing cross‑sectional, single‑stage probability sampling and primarily telephone data collection.

PVS, co‑ordinated by the Quality Evidence for Health System Transformation (QuEST) Network. The last round spanned 25 countries including low‑ and middle‑income settings and surveys the general adult population aged 18 and over, using rapid, cross‑sectional data collection, mainly through telephone interviews with mixed‑mode supplementation.

SHARE, co‑ordinated internationally by the SHARE Berlin Institute, is a longitudinal biennial panel survey. The last round covered 27 European countries plus Israel, targeting individuals aged 50 and over (and their partners of any age), with probability‑based sampling from population registers and predominantly face‑to‑face interviews.

Source: Authors, based on the information provided in Table 1.

The intersection of country coverage across the five international surveys remains limited when examined across their latest data collections (Table 1). PaRIS Cycle 1 includes 19 OECD Member and Partner countries, while EHIS Wave 3 covers EU Member States and selected partners; overlap is therefore concentrated in EU countries participating in PaRIS, namely Belgium, Czechia, France, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Romania, Slovenia and Spain. The People’s Voice Survey is implemented along with PaRIS in Greece, Italy, Romania and the United States, and in general PVS has a broader geographic scope in low and middle‑income countries. Overlap with SHARE Wave 9 is restricted to European PaRIS participants, including Luxembourg and Switzerland, while Israel participates in SHARE but not in PaRIS Cycle 1. The IHP survey shows limited overlap with PaRIS, including Australia, Canada, France, the Netherlands, Switzerland and the United States.

Table 1. The intersection of country coverage in the last rounds of PaRIS, EHIS, the IHP survey, PVS and SHARE

	Intersection of country coverage with PaRIS
EHIS	Belgium; Czechia; France; Greece; Ireland; Italy; Luxembourg; Netherlands; Portugal; Romania; Slovenia; Spain; and Norway
The IHP survey	Australia, Canada, France, Netherlands, Switzerland, United States
PVS	Greece, Italy, Romania, United States
SHARE	Belgium; Czechia; France; Greece; Italy; Luxembourg; Netherlands; Portugal; Romania; Slovenia; Spain

All five surveys are based on a core survey-specific framework at the international level for collecting information and are implemented through national teams. However, how surveys are conducted in national contexts depends on different types of implementation agents. These implementation agents range from national statistical offices and academic consortia to health ministries and contracted research institutes. Both PaRIS and EHIS are conducted through official contacts across member countries, while other surveys are conducted through partnerships with research institutes and survey agencies.

2.2. Differences in purpose and scope lead to distinct approaches in survey design and implementation

The target populations differ across surveys (Table 2). EHIS includes people aged 15 and over living in private households and PVS surveys people aged 18 and over. PaRIS, the IHP survey and SHARE target older population groups. The IHP survey’s target population varies depending on the focus of each wave driven by healthcare priorities of the period. The latest wave, conducted in 2024, targeted people aged 65 and over. SHARE includes people aged 50 and over living in private households and their caregivers. PaRIS has a distinct focus on people aged 45 and above who had contact with their primary care practice in the six months prior to sampling. This is an intentional feature of PaRIS to focus on older people who are more likely to have chronic conditions, which is the main scope of PaRIS.

These differences in age coverage and eligibility criteria have important implications for comparability. Surveys focussing on older populations are more likely to capture individuals with higher prevalence of chronic conditions, greater healthcare needs and more frequent interactions with the health system, which can influence reported outcomes and experiences. By contrast, broader population-based surveys may include a broader age range and generally healthier individuals, which can be an essential source of information for broader population health issues such as inequalities or health behaviours such as participation in screening activities or smoking. PaRIS uniquely restricts its sample to people with recent contact with primary care, whereas in EHIS, PVS, the IHP survey and SHARE a subset of respondents are recent healthcare users, including non-users as well. As a result, PaRIS indicators are more reflective of experiences of users of services and the impact of healthcare on these, while more general population-based surveys are better able to reflect e.g. prevalence rates in the population or figures on access barriers.

Differences in question frameworks, instruments and recall periods influence both what is measured and how comparable results are across surveys. PaRIS combines validated PROMs and PREMs (e.g. PROMIS, WHO‑5, P3CEQ) with care‑experience items and with the inclusion of care experiences for relatively short recall windows (e.g. 7 days for symptoms, 2 weeks for well-being, last consultation for specific care experiences and past 12 months for overall care experiences), enabling clinically relevant assessment of outcomes and care processes among recent primary care users. The IHP survey relies more on long-standing standardised experience questions, with fewer validated outcome scales, focussing on access, co‑ordination and affordability. EHIS integrates health status, healthcare utilisation and determinants, including some validated tools (e.g. WHO‑5, PHQ‑8), generally with longer recall frames suited to population surveillance but without provider-level linkage. PVS uses shorter, general measures centred on overall health perceptions, system confidence and trust rather than detailed clinical outcome instruments, tied to recent experiences or general views. SHARE focusses on health, functioning and socio‑economic circumstances in ageing populations using validated scales, but not practice‑specific experience measures. Shorter recall periods, as in PaRIS, tend to improve reporting accuracy for recent events but may capture more short-term variation, whereas longer recall periods smooth fluctuations but increase recall bias.

Table 2. Comparing the scope of international health surveys

Dimension	PaRIS cycle 1	EHIS wave 3	IHP (2024 round)	PVS cycle 1	SHARE wave 9
Participating countries	19 OECD Member and partner countries (Australia; Belgium; Canada; Czechia; France; Greece; Iceland; Italy; Luxembourg; Netherlands; Norway; Portugal; Slovenia; Spain; Switzerland; United States, Wales, Saudi Arabia, Romania)	27 EU member states (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovak Republic, Slovenia, Spain, and Sweden) and Norway	10 highly industrialised countries (Australia, Canada, France, Germany, Netherlands, New Zealand, Sweden, Switzerland, United Kingdom, the United States)	25 countries including low and middle income (Ethiopia, Kenya, Nigeria, South Africa, China, India, Laos, Korea, Greece, Italy, Romania, United Kingdom, Mexico, United States, Argentina (Province of Mendoza), Colombia, Peru, Uruguay, Germany, Switzerland, Japan, Ecuador, Somaliland, Malawi, and Nepal)	27 European countries (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovak Republic, Slovenia, Spain, and Sweden) plus Israel
Implementation agent	Co-ordinated by OECD with voluntary country participation, implemented through national project managers appointed by Ministries of Health (e.g. health agencies, academics or research institutions)	Co-ordinated by Eurostat with mandatory country participation under EU regulation, implemented by national statistical institutes	Co-ordinated by the Commonwealth Fund; core and national partners	Led by the QuEST Center at Washington University in St. Louis in partnership with QuEST Network member institutions in each participating country	International co‑ordination via SHARE Berlin Institute/MEA; implemented by national survey agencies/research teams
Target Population	Primary care users aged ≥45 with recent primary care contact (6 months)	General population aged ≥15 living in private households	General population aged ≥65	General adult population aged ≥18	Individuals aged ≥50 (and their partners regardless of age)
Survey design	Cross-sectional nested design (patients in practices, which are in countries) with multi-stage sampling: probability samples of primary care practices first, then probability sampling patients of these primary care practices	Cross-sectional with multi-stage design: Probability samples from national population or household registers, drawing household clusters with one adult selected per household	Cross-sectional single stage probability sampling using overlapping landline/cell random-digit-dialling in most countries, with registry samples and probability panels	Cross-sectional. Single‑stage probability sampling using random-digit-dialling, probability panels, or known-list sampling, supplemented with household surveys in rural areas	Longitudinal (biennial) panel survey with refreshment samples; Single stage probability-based sampling
Sampling Frame	Two-stage: primary care practices from national/regional healthcare provider lists, then patients from practice registries or central databases	National population/household sampling frames drawn by national statistical institutes following Eurostat guidance.	Random-digit-dialling overlapping landline/cell phone frames or population registries	Random-digit-dialling or known-list phone sampling; supplemental face‑to-face samples where mobile coverage is low; probability-based panels in some high-income settings	Preferred sampling frame: official person register of the residential population (with age info where available); alternatives used if registers unavailable
Sample Size	Over 107 000 respondents (on average 5 600 per country)	Over 321 000 respondents (On average 7 225 per country)	Over 14 000 respondents ((300‑4 000 per country)	Over 70 000 respondents (on average 2 000 per country)	Over 160 000 respondents; regular fieldwork collected ~70 000‑72 000
Questionnaire design	Two standardised instruments: patient questionnaire with four main domains (PROMs/PREMs notably for chronic conditions, health behaviours and health capabilities) and a primary care practice questionnaire on characteristics	A harmonised Eurostat questionnaire with four modules: health status, health determinants, healthcare use/unmet needs, and background	A standardised questionnaire with core modules on access, affordability, co‑ordination and quality	A standardised questionnaire covering patterns of healthcare use, care quality, user experience, system competence, and confidence in the health system	Core questionnaire covering health, socio‑economic status and social/family networks, and wave‑specific modules
Data Collection Mode	Digital-first (online) with paper/telephone alternatives	Face‑to-face interviewing predominates (CAPI*/PAPI**),	Primarily telephone with online options	Primarily CATI*** with mixed-mode alternatives	Primarily CAPI* with additional telephone interviewing in some contexts
Completion time (average)	30‑35 minutes	Estimated* about 25‑45 minutes	19‑30 minutes	20‑25 minutes	Estimated* about 45‑90 minutes
Field Period	2023-2024 (for practices on average 11.8 weeks (range: 4‑20 weeks); for patients on average 13 weeks (range: 5‑27 weeks))	2019 (on average 32 months)	2024 (6‑14 weeks per country)	2022-2023 (rapid data collection of 4‑8 weeks per country)	2021-2022 with varying country-specific timing
Response Rates	Patients: Median 24% (Country range 6%‑42%)	Median 44% (Country range 22‑78%)	Median 14% (Country range: 2.8%‑50.3%)	Country range 3% to 17%	household response rates from ~18% to >90%, with individual response rates often ~70‑95%

Note: CAPI: Computer-assisted personal interviews; PAPI: Pen-and-paper personal interviews; CATI: Computer-assisted telephone interviews.

Source: 2024 Commonwealth Fund International Health Policy Survey of Older Adults – SSRS Methodology Report – 2024. SHARE Methodology Volume – Wave 9. European Health Interview Survey (EHIS wave 3) – Methodological manual (Eurostat). Population assessment of health system performance in 16 countries using the People’s Voice Survey (WHO Bulletin, 2024). PaRIS data and methods chapter – Does Healthcare Deliver?. PaRIS questionnaires (OECD). * Estimations are done by the authors given the length of the questionnaires.

Unlike most international population surveys, PaRIS uses a nested multilevel design in which patients are sampled within primary care practices, which are situated within countries. This allows PROMs and PREMs to be analysed in relation to practice characteristics and care processes, while accounting for clustering at the practice and country levels. By applying a multilevel design, PaRIS can partition variation at patient, practice and country levels, by also comparing not only between countries but also within countries (Groenewegen et al., 2024[26]). Such multilevel approaches are widely recognised as essential in health services and public health research, where outcomes are shaped by factors operating across individual, practice and system levels (Leyland and Groenewegen, 2020[27]).

Differences in data-collection modes have important implications for comparability, response patterns and the types of respondents reached. Face‑to-face surveying, used mainly in EHIS and SHARE, typically achieves higher response rates and better coverage of older or digitally excluded populations, but are more costly and may introduce interviewer and social desirability effects. Telephone‑based surveys, such as PVS and parts of the IHP survey, are more cost-efficient and easier to standardise across countries but may under-represent individuals less likely to respond to phone surveys. PaRIS uses a digital-first approach complemented by paper and telephone options (in some countries), which enables large‑scale implementation and faster processing while reducing interviewer effects but may still introduce biases linked to digital literacy and mode effects. Mixed-mode designs can reduce coverage gaps but may generate mode effects, where responses differ by interview format. Consequently, differences in reported experiences or outcomes across surveys may partly reflect mode‑related measurement and coverage effects rather than true differences in health system performance.

Differences in fieldwork periods and timing might also influence comparability. PaRIS involved a fieldwork period of about six months (2023‑2024), reflecting the complexity of practice‑based recruitment and co‑ordination with providers. By contrast, the IHP survey and PVS typically use shorter, more standardised field periods (around 6‑14 weeks for the IHP survey and often 4‑8 weeks per country for PVS), while EHIS is implemented in multi-year waves within official statistical programmes, and SHARE Wave 9 fieldwork ran from October 2021 to September 2022 with country-specific variation. Longer or staggered field periods increase exposure to temporal effects, such as policy changes or seasonal patterns, whereas shorter, tightly defined periods improve cross-country synchronicity but allow less flexibility to address recruitment challenges.

2.3. Variations in sample size and response rates mirror survey purpose and design

Survey performance, reflected in sample size and response rates, has direct implications for validity and is closely linked to each survey’s primary purpose. EHIS and SHARE, with very large samples and generally higher response rates, are well suited for population surveillance and subgroup monitoring, providing stable estimates and broad representativeness, though with less focus on specific healthcare‑user groups. PaRIS, while smaller than EHIS and SHARE, achieves substantial within-country samples among primary care users and is designed to analyse care experiences and outcomes in relation to service delivery; its lower and more variable response rates require careful weighting and sensitivity checks, but are partly a function of its more complex multilevel design. It should also be noted that PaRIS Cycle 1 represents the initial implementation of a new international survey. Therefore, these issues are relevant for interpreting the current findings but may be mitigated or resolved in future cycles.

The IHP survey and PVS feature small samples with low response rates, which may limit statistical precision and increase the risk that results reflect respondent selection, but this aligns with their focus on perceptions, policy-relevant signals and rapid cross-country insight rather than detailed system performance measurement. Across surveys, lower response rates heighten the risk of under-representing disadvantaged or less engaged groups, while larger samples improve precision but do not eliminate bias without appropriate adjustment. Consequently, differences in findings across surveys may reflect not only health system performance but also how survey design choices balance feasibility, target populations and intended analytical use.

2.4. While all surveys include patient-reported measures, the overlap in subdomains covered is minimal

Across the five international surveys, coverage does not fully coincide; rather, each survey has specific strengths in the subdomains it was designed to assess (Figure 1). The reference subdomains in PaRIS, EHIS and SHARE include an extensive number of questions on functioning and health behaviours, while the IHP survey and PVS have a higher number of questions regarding care experiences. The approach used to examine the comparability of surveys and questionnaire items are presented in Box 2.

Figure 1. Taking the PaRIS subdomains as the reference, each survey demonstrated a distinct focus, with no single survey fully aligned with the others

Note: EHIS: European Health Interview Surveys, IHP: International Health Policy survey, PaRIS: Patient Reported Indicator Surveys, PVS: People’s Voice Survey, SHARE: the Survey of Health, Ageing and Retirement in Europe.

Source: Authors.

2.4.1. PREMs

PREMs-related subdomains show substantial variation. The IHP survey and PVS provide extensive coverage, particularly in access, quality of care, people‑centred care, safety, co‑ordination, and continuity. Within the quality subdomain, PVS includes distinctive questions assessing perceptions of the overall quality of the healthcare system, representing a system-level evaluative dimension that is less prominent in the other surveys. EHIS includes a smaller number of PREMs-related questions, primarily focussed on access and selected aspects of quality. SHARE contains only limited PREMs content.

2.4.2. PROMs

PROMs are unevenly present across surveys. SHARE includes extensive coverage of functioning and symptoms, consistent with its focus on health and ageing. EHIS includes questions on self-rated health, functioning, and symptoms, though to a more limited extent. The IHP survey includes only a small number of PROMs-related questions, primarily focussing on self-rated health. PVS includes limited PROMs content, with an emphasis on symptoms rather than broader functioning or quality of life. PaRIS covers health status by measuring physical health, mental health, social functioning, overall well-being, general health as well as symptoms such as pain, fatigue and breathlessness.

2.4.3. Health and healthcare capabilities

The health and healthcare capabilities category represents a distinctive dimension within the PaRIS framework. Healthcare capabilities refer to the skills and resources patients need to manage their care and are operationalised through a set of behavioural and self-efficacy based items that collectively capture how individuals understand, navigate and assume responsibility for their care. PaRIS also makes a distinction between active patient engagement and passive action of receiving health information from a healthcare professional.

Box 2. Assessing the comparability of surveys and questionnaire items

Coding and classification procedure

Survey questions from EHIS, the IHP survey, PVS and SHARE were manually reviewed and assigned to PaRIS subdomains. When surveys used constructs or modules that matched PaRIS subdomains, questions were directly classified into those subdomains. If subdomains were not clearly labelled or if overlap was partial, classification was based on a detailed assessment of their description and underlying purpose. Each question was assigned to only one subdomain. Multi-concept questions were classified according to their dominant construct. Sixteen questions were deemed comparable between PaRIS and EHIS, the IHP survey, PVS or SHARE.

Comparative analysis strategy

Subdomain-level comparison assessed the presence or absence of coverage across surveys and the relative breadth of coverage within each PaRIS subdomain.

Indicator-level comparison identified questions that were potentially comparable across surveys based on conceptual alignment, similarity of wording and constructs, as well as recall periods and response formats.

Differences in question wording, recall periods, and response formats were explicitly considered when assessing comparability. Questions were deemed meaningfully comparable only when differences could be reasonably reconciled, for example, through recoding or alignment with response categories. Where response formats could not be harmonised, questions were classified as conceptually related but not strictly comparable.

2.4.4. Health behaviours

Several questions in PaRIS measure health behaviours and attitudes, such as smoking, alcohol use, physical activity and dietary habits, seeking to understand personal health risks, raising concerns when something seems wrong, and bringing externally sourced information to consultations. The category also includes a structured set of self-efficacy questions that assess confidence in managing one’s own health and well-being, following professional advice, changing habits or lifestyle, recognising when medical care is necessary, and using online information to make health decisions.

Health behaviours are most extensively covered in EHIS and SHARE. EHIS includes a substantial number of questions related to physical activity, smoking, alcohol consumption, and diet. SHARE similarly includes multiple questions on smoking, alcohol use, diet, and physical activity, consistent with its life‑course and ageing perspective. In contrast, the IHP survey and PVS include little or no coverage of these subdomains.

2.5. Only a few indicators are meaningfully comparable across all surveys

Across the five surveys, the number of questions that can be meaningfully compared remains limited, largely due to differences in item design, operational definitions, and survey objectives (Figure 2). The overlapping space is largest in patient experience and care‑quality domains (PaRIS-IHP-PVS), moderate in health outcomes (EHIS-SHARE-PaRIS), and minimal in lifestyle indicators (EHIS-PaRIS). This underlines that cross‑survey harmonisation efforts must recognise that these instruments are complementary rather than substitutable, each contributing specific clusters of comparable indicators aligned with its core purpose.

PaRIS, the IHP survey, and PVS show a strong concentration of indicators in patient‑centred care dimensions, particularly self‑management support and quality of care, co‑ordination, continuity, and trust. These domains show high comparable counts for the IHP survey, PVS and PaRIS, indicating that these three surveys share a common design emphasis on measuring people’s experience of health services and the performance of healthcare systems. In contrast, EHIS and SHARE contribute few comparable indicators in these domains, reflecting their fundamentally different missions: EHIS as a public health indicator system and SHARE as an ageing and life‑course outcomes survey.

EHIS has a strong emphasis on “health behaviours and lifestyle”, including alcohol, smoking, diet, physical activity. This dominance reflects EHIS’ role in EU population health monitoring and its alignment with non-communicable disease risk‑factor surveillance. SHARE contributes some indicators in lifestyle and chronic conditions, but not at the breadth or depth of EHIS. PaRIS, the IHP survey and PVS contribute minimally to these behavioural domains, highlighting that they are not designed as epidemiological surveillance instruments and therefore produce few cross‑survey comparable items in these areas.

SHARE includes a comprehensive set of PROMs, including self‑reported health, functioning, symptoms, and health‑related quality of life, reflecting its longitudinal focus on ageing populations and functional trajectories. EHIS also contributes a notable cluster in these areas, though with more emphasis on general self‑reported health and chronic conditions rather than functioning. By contrast, the IHP survey and PVS contribute very few outcome‑oriented indicators, again underlining their focus on system experience and performance.

While 16 indicators were identified for general comparison, a stricter comparison was conducted on four selected indicators: experienced quality of care, perceived general health, confidence to self-manage and hospitalisations. The next section focusses on further analysis conducted on the comparable set of indicators across PaRIS, EHIS, the IHP survey and PVS, restricted to countries present in both PaRIS and the relevant comparison survey.

Figure 2. When compared at the indicator level, no single survey produces a complete balanced suite of comparable indicators with PaRIS

Note: EHIS: European Health Interview Surveys, IHP: International Health Policy survey, PaRIS: Patient Reported Indicator Surveys, PVS: People’s Voice Survey, SHARE: The Survey of Health, Ageing and Retirement in Europe.