Post-stroke Quality of Life Index: A quality of life tool for stroke survivors from Sri Lanka

Abstract

Background: Burden of stroke is rising due to the demographic and epidemiological transitions in Sri Lanka. Assessment of success of stroke-management requires tools to assess the quality of life (QOL) of stroke survivors. Most of currently used QOL tools are developed in high-income countries and may not reflect characteristics relevant to resource-constrained countries. The aim was to develop and validate a new QOL tool for stroke survivors in Sri Lanka. Methods: The COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) checklist was referred. A conceptual framework was prepared. Item generation was done reviewing the existing QOL tools, inputs from experts and from stroke survivors. Non-statistical item reduction was done for the 36 generated items with modified-Delphi technique. Retained 21 items were included in the draft tool. A cross sectional study was done with 180 stroke survivors. Exploratory Factor Analysis was done and identified factors were subjected to varimax rotation. Further construct validity was tested with 6 a-priori hypothesis using already validated tools (SF-36, EQ-5D-3 L) and a formed construct. Internal consistency reliability was assessed with Cronbach alpha. Results: Four factors identified with principal-component-analysis explained 72.02% of the total variance. All 21 items loaded with a level > 0.4. The developed tool was named as the Post-stroke QOL Index (PQOLI). Four domains were named as "physical and social function", "environment", "financial-independence"and "pain and emotional-wellbeing". Four domain scores of PQOLI correlated as expected with the SF-36, EQ-5D Index and EQ-5D-VAS scores. Higher domain scores were obtained for ambulatory-group than the hospitalized-group. Higher scores for financial-independence domain were obtained for the group without financial-instability. Five a-priori hypothesis were completely proven to be true. Cronbach-alpha level ranged from 0.682 to 0.906 for the four domains. Conclusions: There is first evidence for sufficient construct validity of the PQOLI as a valid QOL tool for measuring the QOL of stroke survivors with satisfactory internal consistency reliability.