1. Comparative statistics on the accomplishments of thirteen mental hospitals and three state schools for mental defectives are prepared each month by the Division of Statistics of the Massachusetts State Department of Mental Health. Sets of tables are made available to the Commissioner and the superintendents of the various state hospitals and schools.2. Four factors in movement of patient population are analyzed each month: (1) Patients discharged to the community, (2) Patients dying in hospital, (3) Patients placed on visit, and (4) Patients leaving hospital on escape. For example, in the discharges (Table 1), the number of patients severing connection with the hospital during the month is compared with the number of cases under care during the same month. A discharge rate for the hospital is calculated which may be compared with the discharge rates of the other hospitals shown on the same table. Similar tables are made up which present the monthly death rates, visit rates and escape rates for all hospitals (Tables 2, 3, and 4).3. On each of the four tables the standings of the hospitals are arranged in order, the hospital making the best showing being placed at the top of the table. A Summary table is then made up which gives each hospital a standing for the month (Table 5). Thus, a hospital which had a high discharge rate, a low death rate, a high visit rate and a low escape rate would record a high position or standing for the month. Superintendents have found the five tables of this group very useful. They are in a position to take the comparative data into staff meeting and discuss with their physicians the success or failure of the psychiatric and medical care of the hospital in question.4. An analysis of outcome is presented in Table 6 of the combined monthly report. The admissions of a single month one year ago are studied for each hospital and the outcome of those admissions at the end of the present month is outlined. In this particular instance the admissions of October, 1939 are studied for outcome at the end of October, 1940. The admissions of one year ago are still in hospital, are out of hospital on visit, or have been discharged. The first- place hospital showed 75 per cent of admissions of one year ago were out of hospital; the last-place hospital had only 30 per cent out of hospital (Graph 1). Hospitals showing high rates for retention of patients in comparison with other hospitals of the same class, are quick to review their administrative procedures in reference to the discharge of patients to the community.5. A study of the factor of readmission is offered in Table 7 of the monthly report. Patients who left hospitals as discharges during a one-month period two years ago are followed up to see whether or not they have been readmitted during the interim. Readmission is not confined to return to the original hospital but is recorded if the patient was readmitted to any mental hospital in the state. In the particular group studied the hospital making the best showing revealed a figure of 10 per cent of the discharges of October, 1938 (Table 7 and Graph 2) readmitted up to the end of October, 1940. The hospital with the most patients returned had 22.5 per cent of the discharges of October, 1938, readmitted within the two-year period. The data of this table serve as a check on the success that various hospitals have had in keeping patients in the community following discharge.6. The completion of the statistical work of the sixteen institutions under the Department of Mental Health has been a duty of the Division of Statistics since 1928. Complete sets of the eighteen standard tables of The American Psychiatric Association are prepared for each mental hospital. In the case of the state schools the standard tables of the American Association on Mental Deficiency are prepared. They are then forwarded to each superintendent who discusses the findings and includes both the discussion and the tables in the annual report of his institution.7. A new comprehensive master table has been added to the standard tables and has proved to be of great usefulness. In this table the 120 psychoses and sub-groups of the standard classification are placed in a column at the left. Across the table are placed the numbers falling in the admissions, discharges and deaths during the year and the numbers in the resident population and those out on visit, etc., at the end of the year. For demonstration purposes an excerpt from the complete table is given. This presents the figures on dementia præcox only, and for a single hospital (Table 8).8. Two new developments have been added recently to the comprehensive table. Discharge rates and death rates for each psychosis and sub-group are shown. The rates are on an annual basis and enable the administrator to compare the discharge rates and death rates for a specific psychosis in his hospital with those of any hospital in the state (Tables 9 and 10).9. Discharge rates (1940) for Massachusetts admission hospitals in reference to patients diagnosed manic-depressive psychosis, are outlined in Graph 3. All hospitals combined discharged 166 patients per 1000 patients under care with the same diagnosis. The leading hospital discharged 237 patients per 1000 under care, the last hospital, 73 per 1000.10. Death rates (1940) for patients diagnosed manic-depressive psychosis in all admission hospitals are outlined in Graph 4. All hospitals combined present a death rate of 32 per 1000 under treatment of the same diagnosis. The hospital showing the low death rate had 21 deaths per 1000 patients under treatment. The hospital with the high death rate had 50 deaths per 1000 patients.11. Monthly variations in discharge rates of mental patients leaving hospitals during the years 1938, 1939 and 1940, are shown in Graph 5. January and February are low in the discharge of mental patients to the community. From April to July the high discharge rates are shown. From September through December, the discharge rates tend to occupy an intermediate position.12. Monthly variations in the numbers of patients placed on visit during the years 1938-1940, are shown in Graph 6. January and February are low in patients placed on visit. A higher level of visit rates is observed from April to October with a mid- summer high in July. November and December are the high visit months. Are patients released on visit through requests of relatives rather than at instigation of medical staffs? One observes that the Fourth of July, Thanksgiving and Christmas are the high points for visits during each of the three years studied.13. Monthly fluctuations in the number of deaths in mental hospitals through the years 1938-1940 are observed in Graph 7. The high death rates occur in the winter and early spring months. The low death rates are observed from June to October. Death rates in mental disease follow those of the general population in the various months of the year. However, the rates are on a level which is about eight times as high as those of the population.14. Length of hospital stay of patients discharged is of vital interest to administrators, as it tests the time element necessary for the successful treatment of patients prior to return to the community. In 1940 the average length of hospital stay of all patients discharged from admission hospitals in Massachusetts was ten months (.85 years). The hospital in first position showed a hospital stay of seven months (.61 years). The hospital in last position revealed a hospital stay of one year and two months (1.18 years). Is the last hospital too conservative in its policy relating to the release of patients?15. Monthly and annual figures on the movement of patient population can be very useful tools in the successful administration of mental hospitals. Mothers and fathers, sisters and brothers, wives and husbands have the right to know that every effort is being made by hospital authorities to return their loved ones to them at the earliest possible moment. Careful checking of results of treatment and of efforts to effect an early return of patients to the community are obvious duties of the administrator. Careful study of the figures on movement of patient population will tell the administrator a great deal about the efficiency of his standard procedures in these matters. As one able psychiatrist has said, "Statistics will tell us what is the matter with our methods if we will only listen."