# Prevalence of preserved ratio impaired spirometry and restrictive spirometry pattern in the general population: a systematic review and multi-level meta-analysis of studies from multiple countries

## TL;DR

This study estimates the global prevalence of two lung function patterns, PRISm and RSP, and finds they are common, especially among smokers and older adults.

## Contribution

The study provides the first global pooled estimates of PRISm and RSP prevalence and identifies key risk factors across diverse populations.

## Key findings

- The global prevalence of PRISm is 10.60% and RSP is 12.09% in the general population.
- Current smokers and older adults are at higher risk for PRISm and RSP.
- Smoking and comorbidities like asthma and diabetes are significant risk factors for both conditions.

## Abstract

Both preserved ratio impaired spirometry (PRISm) (defined as a forced expiratory volume in one second (FEV1) <80% of predicted, while the ratio of FEV1 to forced vital capacity (FVC) is ≥0.7) and restrictive spirometry pattern (RSP) (defined as FVC<80% of predicted, while the FEV1/FVC ratio ≥0.7) are associated with an increased risk of mortality. The global prevalence of PRISm and RSP in the general population remains unclear. Therefore, we aimed to estimate the prevalence and identify risk factors of PRISm and RSP in the general population, and to examine variations across subgroups defined by gender, smoking status, WHO regions, and World Bank income levels.

We searched three databases for studies that reported the prevalence of PRISm and RSP, and their associated risk factors in the general population. We conducted a multi-level meta-analysis, along with standard random-effects modelling, to estimate the pooled prevalence and identify key risk factors, and performed meta-regression and sensitivity analyses to assess the robustness of the results.

We identified a total of 57 studies reporting population-based data from 31 countries. We included 48 studies for meta-analysis using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) definition, resulting in a pooled sample of 1 129 807 participants. The pooled prevalence of GOLD-PRISm was 10.60% (19 studies; 95% confidence interval (CI) = 8.12, 13.73), while the prevalence of GOLD-RSP was 12.09% (23 studies; 95% CI = 7.90, 18.04). The simultaneous combined prevalence of GOLD-PRISm and RSP was 11.79% (38 studies; 95% CI = 9.11, 15.12). Subgroup analysis showed that current smokers (13.37% vs. 10.18% in ex-smokers and 10.87% in non-smokers), and Western Pacific Region populations (11.26%) had higher prevalence rates of GOLD-PRISm. Significant risk factors for GOLD-PRISm include older adults, current and former smoking, extreme body mass index, and a history of comorbidities, such as asthma, diabetes, hypertension, and stroke.

We provide a pooled estimate of PRISm and RSP prevalence based on studies from multiple regions, highlighting significant regional and demographic variations. Key risk factors, particularly smoking and comorbidities, should be considered when developing early management strategies.