The military infirmary 1st class at Siak (Bengkalis) is mentioned in the publication of D. Schoute “De Geneeskunde in Nederlandsch-Indie in de 19e eeuw”, GTNI 75 (1935) 10, 827. The article refers to a survey of all the military facilities in 1867 . In that year the infirmary at Siak had on average 20 patients. The infirmary was part of the Military Medical Service (MGD), which in 1867 (the year of the survey of all military facilities) managed a total of 79 facilities (3 large military hospitals, 35 garrison hospitals and 41 infirmaries) with on average 4,244 occupied beds.
Some 25 years later, the Annex D of the Koloniaal Verslag 1890 reports a total of 3,358 inpatients by the end of that year, whereas 52,631 patients have been admitted for the whole of the Netherlands Indies. The report concerns 28 military hospitals, 54 ziekenzalen (infirmaries) and 6 specialized facilities. The average occupation rate of the Siak infirmary is not mentioned, but an infirmary at Bengkalis then has 61 patients admitted that year. The situation by the end of the year 1890 is a presence of 6 patients.
About 1900 the situation of military health facilities was: 30 hospitals, 56 infirmaries and 5 specialized facilities, such as reconvalescent centers and leprosy asylums. The total number of admittances was in 1898: 57,071 and the number of present inpatients by the end of 1898: 3,731. These figures were for the Siak infirmary: 27 admittances and no patients present on 31 December 1899 (See Koloniaal Verslag 1900, Addendum A).
Siak was in the 1930s a subdepartment of the department Bengkalis, Government Eastcoast Sumatra, administratively run by a Controleur Binnenlands Bestuur (Administration of the Interior). The subdepartment existed of the subdistricts Siak, Mempoera, Mandau, Tapang-Kiri and Tapang-Kanan and had 25,000 inhabitants of whom 84 Europeans and 1,300 Chinese. The capital was Siak Sri Indrapoera, situated on the Siak-river (Gonggryp 1934, 1291).