Diare masih menjadi masalah kesehatan masyarakat yang berkaitan erat dengan faktor lingkungan, terutama kualitas dan pengelolaan air minum rumah tangga. Di Provinsi Kalimantan Timur, prevalensi diare berdasarkan Survei Kesehatan Indonesia tahun 2023 sebesar 4,2%. Peningkatan akses terhadap sumber air minum layak belum sepenuhnya menjamin keamanan air pada titik konsumsi. Penelitian ini bertujuan menganalisis hubungan kualitas air minum rumah tangga yang meliputi parameter mikrobiologi, fisik, dan kimia dengan kejadian diare di Provinsi Kalimantan Timur berdasarkan data Surveilans Kualitas Air Minum Rumah Tangga (SKAMRT) 2024. Penelitian ini menggunakan desain cross sectional dengan unit analisisnya adalah rumah tangga. Teknik pengambilan sampel mengikuti metode yang digunakan dalam SKAMRT 2024 yang melibatkan 2.051 rumah tangga. Analisis dilakukan secara deskriptif, uji Chi-square, dan uji regresi logistik ganda. Hasil penelitian menunjukkan bahwa 4,5% rumah tangga memiliki anggota rumah tangga yang mengalami diare. Parameter kualitas air minum yang menunjukkan proporsi tidak memenuhi syarat cukup tinggi adalah E. coli (31,3%), kekeruhan (19,0%), pH (15,0%), krom valensi 6 (46,5%), dan sisa klor pada rumah tangga dengan sumber air minum perpipaan (86,3%). Sebagian besar rumah tangga menggunakan sumber air minum layak (98,0%), memiliki akses air minum kontinu (96,5%), melakukan pengolahan air minum (56,9%), dan memiliki penyimpanan air minum tidak berisiko (95,1%). Parameter kekeruhan, pH, dan krom valensi 6 berhubungan signifikan dengan kejadian diare. Pada model akhir, hubungan E. coli, kekeruhan, dan pH dengan diare berbeda menurut kontinuitas air minum, sedangkan pada parameter sisa klor tidak berhubungan signifikan dengan diare setelah dikontrol kontinuitas air minum dan penyimpanan air minum. Kualitas air minum rumah tangga pada titik konsumsi, khususnya parameter fisik kekeruhan dan parameter kimia pH, berhubungan erat dengan kejadian diare di Provinsi Kalimantan Timur. Hubungan ini sangat dipengaruhi oleh keandalan kontinuitas air minum yang berperan sebagai variabel pemodifikasi efek (effect modifier).

Diarrhea remains a public health issue closely linked to environmental factors, particularly the quality and management of household drinking water. In East Kalimantan Province, the prevalence of diarrhea, according to the 2023 Indonesian Health Survey, was 4.2%. Increased access to improved drinking water sources does not fully guarantee water safety at the point of consumption. This study aims to analyze the association between household drinking water quality—comprising microbiological, physical, and chemical parameters—and the incidence of diarrhea in East Kalimantan Province, using data from the 2024 Household Drinking Water Quality Surveillance (SKAMRT). This study employed a cross-sectional design, with households as the unit of analysis. The sampling procedure followed the methodology of the 2024 SKAMRT, involving 2,051 households. Data were analyzed using descriptive statistics, Chi-square tests, and multivariable logistic regression. The results indicated that 4.5% of households had at least one member who experienced diarrhea. The results showed that 92 households (4.5%) had at least one member who experienced diarrhea. Drinking water quality parameters with a high proportion of non-compliance included E. coli (31.3%), turbidity (19.0%), pH (15.0%), hexavalent chromium (46.5%), and residual chlorine in households utilizing piped water sources (86.3%). Most households used improved drinking water sources (98.0%), had access to a continuous drinking water supply (96.5%), practiced drinking water treatment (56.9%), and utilized low-risk drinking water storage (95.1%). Turbidity, pH, and hexavalent chromium were significantly associated with the incidence of diarrhea. In the final model, E. coli, turbidity, and pH showed significant interactions with water supply continuity on the risk of diarrhea, whereas residual chlorine was not significantly associated with diarrhea after controlling for water supply continuity and water storage practices. Household drinking water quality at the point of consumption, particularly the physical parameter of turbidity and the chemical parameter of pH, is significantly associated with the incidence of diarrhea in East Kalimantan Province. This association is highly influenced by the reliability of water supply continuity, which acts as an effect modifier.