Actually the California Ratio LAW AB 394 which passed in 1999 required increased staffing by acuity.
Before that in 1996 the regulations required the hospital to staff according to a patient classification system.
Here is language of the current regulations. Acuity starts on page 7:
http://www.dhs.ca.gov/lnc/pubnotice/...ation_Text.pdf
...In addition to the requirements of subsection (a), the hospital shall implement a patient classification system as defined in Section 70053.2 above for determining nursing care needs of individual patients that reflects the assessment, made by a registered nurse as specified at subsection 70215(a)(1), of patient requirements and provides for shift-by-shift staffing based on those requirements. The ratios specified in subsection (a) shall constitute the minimum number of registered nurses, licensed vocational nurses, and in the case of psychiatric units, licensed psychiatric technicians, who shall be assigned to direct patient care. Additional staff in excess of these prescribed ratios, including non-licensed staff, shall be assigned in accordance with the hospital's documented patient classification system for determining nursing care requirements, considering factors that include the severity of the illness, the need for specialized equipment and technology, the complexity of clinical judgment needed to design, implement, and evaluate the patient care plan, the ability for self-care, and the licensure of the personnel required for care. The system developed by the hospital shall include, but not be limited to, the following elements:
(1) Individual patient care requirements.
(2) The patient care delivery system.
(3) Generally accepted standards of nursing practice, as well as elements reflective of the unique nature of the hospital's patient population.
(c) A written staffing plan shall be developed by the administrator of nursing service or a designee, based on patient care needs determined by the patient classification system. The staffing plan shall be developed and implemented for each patient care unit and shall specify patient care requirements and the staffing levels for registered nurses and other licensed and unlicensed personnel. In no case shall the staffing level for licensed nurses fall below the requirements of subsection (a). The plan shall include the following:
(1) Staffing requirements as determined by the patient classification system for each unit, documented on a day-to-day, shift-by-shift basis.
(2) The actual staff and staff mix provided, documented on a day-to-day, shift-by-shift basis.
(3) The variance between required and actual staffing patterns, documented on a day-to-day, shift-by-shift basis.
(d) In addition to the documentation required in subsections (c)(1) through (3) above, the hospital shall keep a record of the actual registered nurse, licensed vocational nurse and licensed psychiatric technician assignments to individual patients by licensure category, documented on a day-to-day, shift-by-shift basis. The hospital shall retain:
(1) The staffing plan required in subsections (c)(1) through (3) for the time period between licensing surveys, which includes the Consolidated Accreditation and Licensing Survey process, and
(2) The record of the actual registered nurse, licensed vocational nurse and licensed psychiatric technician assignments by licensure category for a minimum of one year.
(e) The reliability of the patient classification system for validating staffing requirements shall be reviewed at least annually by a committee appointed by the nursing administrator to determine whether or not the system accurately measures patient care needs.
(f) At least half of the members of the review committee shall be registered nurses who provide direct patient care.
(g) If the review reveals that adjustments are necessary in the patient classification system in order to assure accuracy in measuring patient care needs, such adjustments must be implemented within thirty (30) days of that determination.
(h) Hospitals shall develop and document a process by which all interested staff may provide input about the patient classification system, the system's required revisions, and the overall staffing plan.
(i) The administrator of nursing services shall not be designated to serve as a charge nurse or to have direct patient care responsibility, except as described in subsection (a) above.
(j) Registered nursing personnel shall:
(1) Assist the administrator of nursing service so that supervision of nursing care occurs on a 24-hour basis.
(2) Provide direct patient care.
(3) Provide clinical supervision and coordination of the care given by licensed vocational nurses and unlicensed nursing personnel.
(k) Each patient care unit shall have a registered nurse assigned, present and responsible for the patient care in the unit on each shift.
(l) A rural General Acute Care Hospital as defined in Health and Safety Code Section 1250(a), may apply for and be granted program flexibility for the requirements of subsection 70217(i) and for the personnel requirements of subsection (j)(1) above.
(m) Unlicensed personnel may be utilized as needed to assist with simple nursing procedures, subject to the requirements of competency validation. Hospital policies and procedures shall describe the responsibility of unlicensed personnel and limit their duties to tasks that do not require licensure as a registered or vocational nurse.
(n) Nursing personnel from temporary nursing agencies shall not be responsible for a patient care unit without having demonstrated clinical and supervisory competence as defined by the hospital's standards of staff performance pursuant to the requirements of subsection 70213(c) above.
(o) Hospitals which utilize temporary nursing agencies shall have and adhere to a written procedure to orient and evaluate personnel from these sources. Such procedures shall require that personnel from temporary nursing agencies be evaluated as often, or more often, than staff employed directly by the hospital.
(p) All registered and licensed vocational nurses utilized in the hospital shall have current licenses. A method to document current licensure shall be established.
(q) The hospital shall plan for routine fluctuations in patient census. If a healthcare emergency causes a change in the number of patients on a unit, the hospital must demonstrate that prompt efforts were made to maintain required staffing levels. A healthcare emergency is defined for this purpose as an unpredictable or unavoidable occurrence at unscheduled or unpredictable intervals relating to healthcare delivery requiring immediate medical interventions and care.