Heavy use of dental services is a major drain on resources, but the reasons and patterns of heavy use of dental services have been little investigated. There is no consensus definition for heavy use of dental services. In primary medical health care, the 10% of persons making the most visits have most often been defined as frequent attenders[1]. From previous studies in primary medical health care settings, we know that frequent attendance may or may not be persistent[2]. In a study in the UK, approximately 30% of heavy consumers remained frequent attenders the next year[3], and, according to a Swedish study, 14% of the frequent attenders persisted after five years[4]. We found no longitudinal studies assessing persistent heavy use of dental services.
A number of factors influence the use of dental care. A theoretical model by Andersen and Newman stresses the importance of characteristics of the oral health service delivery system, changes in medical technology and social norms relating to the definition and treatment of illness, and individual determinants of utilization[5]. Many studies have confirmed the independent relationships between patterns of dental care utilization and individual factors, such as socio-demographic factors[6–11] perceived quality of dental care[12], type of dental care utilized[13] and self-reported oral problems[7, 11]. Most of the studies dealing with oral health services utilization have focused on the individual characteristics while less attention has been paid to societal determinants and health service delivery systems, although they frame the provision of services to the individual[5].
The oral health care provision system in Finland is consistent with the Nordic model typical for the Scandinavian countries[14]. In this model, a Public Dental Service (PDS) employing salaried personnel, run by county councils or municipalities and financed mainly by tax revenues, is responsible for organizing dental care for certain population groups, e.g. children and adolescents and some groups of the elderly or, in some countries, for all those who wish to use the service. Care in the PDS is free for children and youngsters and in some countries also for certain groups of adults. In general, treatment of adults is subsidized and fixed fees are used. In all Nordic countries there is also a private sector, which part of the population (usually those with higher income and education) chooses to use. Private treatment may also be subsidized through national insurance systems[15].
In Finland, between 1956 and 1980, the PDS catered mainly for children and youngsters and adults were supposed to visit private dentists or denturists. In the 1980s, young adults were successively given access to the PDS, age group by age group. Some special needs groups and World War II veterans were included in the 1990s.
In 2001, when the age limit for access to the PDS was ‘born in 1956 or later’ the dental care provision system was reformed and the age limits restricting adults' use of the PDS were abolished. At the same time, all adults who used the private sector, irrespective of age, became entitled to partial reimbursement of the cost of care from the National Health Insurance[16].
The Dental Care Reform aimed to increase equity by improving adults’ access to care and reducing cost barriers. A premise of this Reform was that oral health care should be distributed primarily according to dental needs[16] and no longer according to age group or having been a patient earlier. The magnitude of the Reform can be seen in the fact that about 40% of Finnish adults in a short period became eligible to use the PDS. This resulted in long waiting lists to the PDS, especially in the bigger cities, partly because treatment in the PDS was cheaper than in the private sector, even after the reimbursement of private care[16]. In 2005, Care Guarantee legislation was introduced in health care including public dental care. This stated that emergency services and non-urgent treatments had to be provided within clear time frames. In the PDS, this meant that emergency services should be given immediately or within three days and non-urgent care within six months to all those who requested and needed it.
Espoo, close to the capital, Helsinki, is the second largest city in Finland. Despite a good supply of private dental services for adults in the capital region, the Dental Care Reform put pressure on the PDS in Espoo. Before the Dental Care Reform Act, until 2001, the PDS of Espoo treated mainly children and young adults up to the age of 30 years and small numbers of older special needs patients. As a result of the reform, adults made up a greater proportion of patients in the PDS of Espoo (36.2% in 2000 and 56.9% in 2009). The PDS operates 27 clinics and patients are free to choose where to go.
In order to make the PDS more effective in Espoo, two studies were conducted to identify heavy users and reasons for heavy use of dental services[17, 18]. These studies showed that 7.0% of the children and youngsters and 10.5% of the adults who had visited the PDS in Espoo were heavy users in 2004. Their visits accounted for 26.3% of all visits by children and youngsters and 31.6% of all adult dental visits. Need for complicated treatment, lack of experience of adult dental care among dentists and dental hygienists and lack of specialists in the PDS resulted in high numbers of dental visits for a number of adult patients[17]. For children, our study revealed two main reasons for heavy use: high amounts of orthodontic treatment provided by general dentists and high numbers of decayed teeth in a small number of children[18].
Our primary objective was to investigate whether or not the adult heavy users persisted as heavy users during the five years following the baseline year. The second objective was to analyse whether the treatment provided differed between baseline heavy and low users of dental services during the follow-up period. We also wanted to study determinants of persistent heavy use of dental services.
