Cost accounting of radiological examinations. Cost analysis of radiological examinations of intermediate referral hospitals and general practice.

The purpose of this study was to analyse the cost structure of radiological procedures in the intermediary referral hospitals and general practice and to develop a cost accounting system for radiological examinations that takes into consideration all relevant cost factors and is suitable for management of radiology departments and regional planning of radiological resources. The material comprised 174,560 basic radiological examinations performed in 1991 at 5 intermediate referral hospitals and 13 public health centres in the Pirkanmaa Hospital District in Finland. All radiological departments in the hospitals were managed by a specialist in radiology. The radiology departments at the public health care centres operated on a self-referral basis by general practitioners. The data were extracted from examination lists, inventories and balance sheets; parts of the data were estimated or calculated. The radiological examinations were compiled according to the type of examination and equipment used: conventional, contrast medium, ultrasound, mammography and roentgen examinations with mobile equipment. The majority of the examinations (87%) comprised conventional radiography. For cost analysis the cost items were grouped into 5 cost factors: personnel, equipment, material, real estate and administration costs. The depreciation time used was 10 years for roentgen equipment, 5 years for ultrasound equipment and 5 to 10 years for other capital goods. An annual interest rate of 10% was applied. Standard average values based on a sample at 2 hospitals were used for the examination-specific radiologist time, radiographer time and material costs. Four cost accounting versions with varying allocation of the major cost items were designed. Two-way analysis of variance of the effect of different allocation methods on the costs and cost structure of the examination groups was performed. On the basis of the cost analysis a cost accounting program containing both monetary and nonmonetary variables was developed. In it the radiologist, radiographer and examination-specific equipment costs were allocated to the examinations applying estimated cost equivalents. Some minor cost items were replaced by a general cost factor (GCF). The program is suitable for internal cost accounting of radiological departments as well as regional planning. If more accurate cost information is required, cost assignment employing the actual consumption of the resources and applying the principles of activity-based cost accounting is recommended. As an application of the cost accounting formula the average costs of the radiological examinations were calculated. In conventional radiography the average proportion of the cost factors in the total material was: personnel costs 43%, equipment costs 26%, material costs 7%, real estate costs 11%, administration and overheads 14%. The average total costs including radiologist costs in the hospitals were (FIM): conventional roentgen examinations 188, contrast medium examinations 695, ultrasound 296, mammography 315, roentgen examinations with mobile equipment 1578. The average total costs without radiologist costs in the public health centres were (FIM): conventional roentgen examinations 107, contrast medium examinations 988, ultrasound 203, mammography 557. The average currency rate of exchange in 1991 was USD 1 = FIM 4.046. The following formula is proposed for calculating the cost of a radiological examination (or a group of examinations) performed with a certain piece of equipment during a period of time (e.g. 1 year): a2/ sigma ax*ax+ b2/ sigma bx*bx+ d1/d5*dx+ e1 + [(c1+ c2) + d4 + (e2 - e3) + f5 + g1+ g2+ i]/n.