A summary of the sample’s characteristics is provided in Table 1, while Table 2 presents the prevalence of unmet healthcare needs in waves 1 and 8 for each country with available data. The findings indicate a substantial increase in unmet healthcare needs across most European countries between 2004 and 2019/2020. The highest prevalence in 2019/2020 was observed in Greece (27.8%), followed by Romania (20.9%) and Estonia (19.9%). Across all countries, the largest increases over time and the highest prevalence rates were observed in specialist physician services, underscoring persistent barriers to accessing specialized care. The prevalence of unmet needs related to general practitioner services and home care remained relatively low in most countries, except for Romania (10% and 8%, respectively) and Hungary (8.4% for general practitioner services). The ranking of countries based on unmet dental needs closely mirrors that of overall unmet healthcare needs, with Greece (17.4%), Romania (11.8%), and Estonia (11.1%) reporting the highest prevalence. Additionally, the proportion of participants reporting unmet pharmaceutical needs is relatively low in most countries, with notable exceptions in Romania (11.6%) and Slovakia (6.3%).

A moderate to strong linear relationship is observed between the prevalence of overall unmet healthcare needs and public health expenditure (expressed as the natural logarithm of per capita spending) (Fig. 1). The negative slope of the trend line (y =  −0.0517x + 8.083) confirms that higher public health expenditure is generally associated with lower unmet healthcare needs. However, the R2 value of 0.282 suggests that while funding plays a significant role, other structural and contextual factors also influence unmet needs.

Relationship between public health expenditure and overall unmet needs among European countries. Note: Dashed lines indicate the median among included countries, i.e., 11.5% for share of individuals with unmet needs and 7.46 for the natural logarithm of public health expenditure per inhabitant pps

To further illustrate this relationship, European countries are categorized into four distinct clusters based on their levels of public health expenditure (high or low) and unmet healthcare needs (high or low). The upper left quadrant (high public health expenditure/low unmet needs) consists mainly of Central and Northern European countries, such as Austria, Belgium, Denmark, Germany, Luxembourg, the Netherlands, Sweden, and Switzerland, as well as two Mediterranean countries, Malta and Spain. These countries demonstrate strong healthcare financing systems that effectively reduce the prevalence of unmet healthcare needs. Some, such as Luxembourg, Denmark, Sweden, and the Netherlands, stand out as well-performing countries with both high expenditure and very low unmet needs, indicating effective healthcare systems with minimal financial barriers.

The lower right quadrant (low public health expenditure/high unmet needs) comprises primarily eastern and southern European countries, including Bulgaria, Hungary, Estonia, Latvia, Lithuania, Poland, and Romania, along with Cyprus and Greece. These countries tend to have weaker healthcare financing structures and higher reliance on out-of-pocket payments, which contribute to significant barriers to healthcare access. Notably, Greece, Romania, and Estonia exhibit the highest levels of unmet healthcare needs, exceeding 20% of the population, reinforcing the strong association between underfunding and poor healthcare access. However, some countries in this group, such as Lithuania and Poland, show slightly better performance despite lower public health expenditure, suggesting that other factors may be mitigating the impact of underfunding.

The lower left quadrant (low public health expenditure/low unmet needs) is the least populated category, including Croatia, Slovakia, and Slovenia. Despite lower public health expenditure, these countries report relatively low unmet needs, suggesting potential efficiencies in their healthcare systems or alternative social support mechanisms that mitigate access issues.

Finally, the upper right quadrant (high public health expenditure/high unmet needs) consists of a heterogeneous group of countries, namely Czechia, Finland, France, and Italy. Despite their higher levels of public health expenditure, these countries still exhibit relatively high unmet healthcare needs, indicating that factors beyond healthcare financing—such as inefficiencies in healthcare service delivery, regional disparities, or supply-side constraints—may contribute to these unmet needs. This highlights an important insight: higher public health expenditure alone does not always guarantee lower unmet needs if healthcare services are not effectively structured and accessible.

Table 3 presents the results of the probit models estimated for each type of unmet healthcare need, controlling for demographic, socioeconomic, and health factors. The findings indicate that higher public health expenditure significantly reduces the probability of unmet needs across all healthcare services, confirming its protective effect. This effect is most pronounced for overall unmet needs, followed by specialist physician services and dental care, suggesting that public investment plays a crucial role in reducing access barriers, particularly in these areas.

Regarding the other predictors, higher age is associated with a significantly lower probability of overall unmet needs, as well as unmet needs related to specialist physician services, medicines, and dental care. Gender differences are also evident, as women are significantly more likely to report overall unmet needs. However, this effect does not reach statistical significance for specific types of unmet needs, suggesting that women may face broader systemic barriers to healthcare but not necessarily in accessing particular services. Marital status and place of residence also play a role, as not being married and living in urban areas are significant risk factors for overall unmet needs and unmet dental care needs. This may reflect differences in social support systems and healthcare availability, with married individuals potentially benefiting from shared financial and logistical resources. Employment status is another important determinant, with working individuals having a significantly lower likelihood of unmet needs related to medicines, dental care, and home care. This suggests that employment may provide financial stability and better healthcare access, possibly through employer-sponsored insurance or income-related advantages. Higher income is a strong protective factor against unmet needs across all healthcare services, except for home care. This highlights the critical role of financial resources in overcoming access barriers, particularly in systems with substantial out-of-pocket costs. Finally, self-reported poor health and limitations in usual activities due to a health problem are strongly associated with increased risk of unmet needs for nearly all healthcare services. The exception is unmet dental care needs, which are not significantly affected by functional limitations, possibly due to the elective nature of dental treatments compared to other essential medical services.

Finally, Fig. 2 presents the average marginal effect of a 20% increase in public health expenditure per capita on the adjusted probability of overall unmet healthcare needs per country, all other things being equal. The magnitude of the effect varies substantially across European countries, highlighting differences in health system responsiveness to public investment. The largest impact is observed in Latvia, Cyprus, and Croatia, where a 20% increase in public health expenditure is associated with a 1.2 percentage point reduction in unmet healthcare needs. Other countries with relatively high reductions include Bulgaria, Romania, Hungary, and Poland, all of which have historically higher levels of unmet healthcare needs. This pattern suggests that in countries where access barriers are more pronounced, additional public investment in healthcare leads to more substantial improvements in service availability and affordability. Conversely, the smallest reductions in unmet needs are observed in Sweden (−0.7 percentage points), Switzerland (−0.7 percentage points), and Denmark (−0.8 percentage points), despite their high levels of public health expenditure. Other well-funded health systems, such as those in Germany, Austria, and Finland, also exhibit smaller effects compared to lower-income countries. This indicates diminishing returns, where once a certain level of public investment is reached, further increases in funding may have a limited impact on reducing unmet needs. In such countries, structural reforms, improvements in healthcare system efficiency, and targeted interventions may be more effective than simply increasing expenditure.

Marginal effect of a 20% increase in public health expenditure per capita on the adjusted probability (in percentage points with 95% CIs) of overall unmet healthcare needs per country. Note: The figure can be read as follows. In Latvia, a 20% increase in public health expenditure per capita decreases the probability of overall unmet needs by 1.2 percentage points, all other things being equal. The estimates of the full probit model are presented in the first column of Table 3. The results are expressed as average marginal effects; the error bars represent 95% confidence intervals (CIs)