The outcome of short- and long-term psychotherapy 10 years after start of treatment.

BACKGROUND: Empirical evidence on whether patients' mental health and functioning will be more improved after long-term than short-term therapy is scarce. We addressed this question in a clinical trial with a long follow-up. METHOD: In the Helsinki Psychotherapy Study, 326 out-patients with mood or anxiety disorder were randomly assigned to long-term psychodynamic psychotherapy (LPP), short-term psychodynamic psychotherapy (SPP) or solution-focused therapy (SFT) and were followed for 10 years. The outcome measures were psychiatric symptoms, work ability, personality and social functioning, need for treatment, and remission. RESULTS: At the end of the follow-up, altogether 74% of the patients were free from clinically elevated psychiatric symptoms. Compared with SPP, LPP showed greater reductions in symptoms, greater improvement in work ability and higher remission rates. A similar difference in symptoms and work ability was observed in comparison with SFT after adjustment for violations of treatment standards. No notable differences in effectiveness between SFT and SPP were observed. The prevalence of auxiliary treatment was relatively high, 47% in SFT, 58% in SPP and 33% in LPP, and, accordingly, the remission rates for general symptoms were 55, 45 and 62%, respectively. CONCLUSIONS: After 10 years of follow-up, the benefits of LPP in comparison with the short-term therapies are rather small, though significant in symptoms and work ability, possibly due to more frequent use of auxiliary therapy in the short-term therapy groups. Further studies should focus on the choice of optimal length of therapy and the selection of factors predicting outcome of short- v. long-term therapy.

Estimation of population attributable fraction (PAF) for disease occurrence in a cohort study design.

The population attributable fraction (PAF) is a useful measure for describing the expected change in an outcome if its risk factors are modified. Cohort studies allow researchers to assess the predictive value of the risk factor modification on the incidence of the outcome during a certain follow-up. Estimation of PAF for both mortality and morbidity in cohort studies with censored survival data has been developed in the recent years. So far, however, censoring due to death in the estimation of PAF for morbidity has been ignored, resulting in estimation of a quantity which is not relevant in practice as some people are likely to die during the follow-up. The risk factors related to the disease incidence may also be related to mortality, and modification of these risk factors is likely to delay the occurrence of both events. Thus, censoring due to death and the impact of risk factor modification must be considered when estimating PAF for disease incidence. We consider both and introduce two measures of disease burden: PAF for the incidence of disease during lifetime and PAF for the prevalence of disease in the population at a certain time. We demonstrate how consideration of censoring due to death changes the estimated PAF for disease incidence and its confidence interval. This underlines the importance of choosing a correct PAF measure depending on the outcome of interest and the risk factors of interest to obtain accurate and interpretable results.

Randomized trial on the effectiveness of long-and short-term psychodynamic psychotherapy and solution-focused therapy on psychiatric symptoms during a 3-year follow-up.

BACKGROUND: Insufficient evidence exists for a viable choice between long- and short-term psychotherapies in the treatment of psychiatric disorders. The present trial compares the effectiveness of one long-term therapy and two short-term therapies in the treatment of mood and anxiety disorders. METHOD: In the Helsinki Psychotherapy Study, 326 out-patients with mood (84.7%) or anxiety disorder (43.6%) were randomly assigned to three treatment groups (long-term psychodynamic psychotherapy, short-term psychodynamic psychotherapy, and solution-focused therapy) and were followed up for 3 years from start of treatment. Primary outcome measures were depressive symptoms measured by self-report Beck Depression Inventory (BDI) and observer-rated Hamilton Depression Rating Scale (HAMD), and anxiety symptoms measured by self-report Symptom Check List Anxiety Scale (SCL-90-Anx) and observer-rated Hamilton Anxiety Rating Scale (HAMA). RESULTS: A statistically significant reduction of symptoms was noted for BDI (51%), HAMD (36%), SCL-90-Anx (41%) and HAMA (38%) during the 3-year follow-up. Short-term psychodynamic psychotherapy was more effective than long-term psychodynamic psychotherapy during the first year, showing 15-27% lower scores for the four outcome measures. During the second year of follow-up no significant differences were found between the short-term and long-term therapies, and after 3 years of follow-up long-term psychodynamic psychotherapy was more effective with 14-37% lower scores for the outcome variables. No statistically significant differences were found in the effectiveness of the short-term therapies. CONCLUSIONS: Short-term therapies produce benefits more quickly than long-term psychodynamic psychotherapy but in the long run long-term psychodynamic psychotherapy is superior to short-term therapies. However, more research is needed to determine which patients should be given long-term psychotherapy for the treatment of mood or anxiety disorders.

A case study in comparing therapies involving informative drop-out, non-ignorable non-compliance and repeated measurements.

Virtually no comparisons of different psychotherapies with long follow-up times have been carried out until now. The Helsinki Psychotherapy Study is a randomized clinical trial, where patients were monitored for 12 months after the onset of study treatments, of which each lasted approximately 6 months. The patients' psychiatric status was measured at five pre-determined time points during the follow-up period. In general, the analyses of trials are complicated in cases where compliance with the given treatment is incomplete or the drop-out from the follow-up is non-ignorable. In the present study, the quality of the treatment deviated from the protocol for some patients and some patients took auxiliary treatments which had similar effects to the study treatment during the study treatment or follow-up period. This might have resulted in standard intention-to-treat analyses providing excessively conservative or liberal conclusions. Non-compliance may have been non-ignorable in some cases, so subject-specific latent factors may have influenced the outcome both directly and indirectly via compliance behaviour. The most and least healthy patients are the most likely to dropout from the follow-up a priori, so the missing data process is informative. The missing data can partly be augmented with surrogate information collected during interviews with patients who dropped out. A Bayesian hierarchical as-treated model, which uses random-effects-based selection models to account for non-ignorable missing data and non-compliance, was compared with different mixed effects models.

Seasonal variation in the incidence of Type 1 diabetes mellitus during 1983 to 1992 in the countries around the Baltic Sea.

AIM: To examine seasonal patterns of incidence of Type 1 diabetes mellitus incidence in children aged 0-14 years in Finland, Sweden, Estonia, Latvia and Lithuania during 1983-1992 (1987-1992 for Finland). METHODS: The study used a method that models incidence data using combinations of sine waves to model seasonal variation around a possible linear trend. RESULTS: In Finland, a significant pattern was found for combined sexes and age groups 0-9 and 10-14 years. A significant pattern was also confirmed for 10-14 year-old boys. In Sweden, the best model with significant pattern was found separately for boys and girls and age groups 0-9 and 10-14 years, however, a significant pattern was confirmed for older girls only. A seasonal pattern in older boys in Finland and girls in Sweden was characterized by two cycles with decreased incidence in June and November-December. The pattern among younger children (0-9 or 5-9 years) had one cycle with a decreased incidence in May-June. In Estonia, a significant pattern was found for the age group 0-14 years and combined sexes. No significant seasonal patterns were found in Latvia and Lithuania. CONCLUSIONS: The seasonal pattern with two cycles among older children and one cycle only among younger children may indicate different triggers of Type 1 diabetes mellitus for different age groups.

Record-high incidence of Type I (insulin-dependent) diabetes mellitus in Finnish children. The Finnish Childhood Type I Diabetes Registry Group.

AIMS/HYPOTHESIS: In Finland, the incidence of Type I (insulin-dependent) diabetes mellitus in children aged 14 years or under is the highest in the world and the trend in incidence has been increasing. Our aim was to determine the most recent trends in incidence and the age distribution at diagnosis of Type I diabetes. METHODS: Data on the incidence of Type I diabetes in Finland nationwide were obtained from two sources: for the period 1965 to 1986 from the Central Drug Registry of the Social Insurance Institution and for the period 1987 to 1996 from the prospective childhood Type I diabetes registry. The annual incidence was calculated per 100,000 people. The increase and the trend in incidence were estimated by fitting the linear regression model with the annual incidence data. RESULTS: During 1987 to 1993 the incidence of Type I diabetes seemed to be rather stable at 36 per 100,000 per year. The incidence has continued to increase thereafter and reached 45 per 100,000 per year in 1996. The analysis of the long-term trend in incidence between 1965 and 1996 showed an absolute incidence increase of 0.67 per year on average being 3.4 % compared with the incidence in 1965. The increase from 1987 to 1996 was highest in very young children 1-4 years old at diagnosis. CONCLUSION/INTERPRETATION: The high incidence of Type I diabetes in Finnish children has thus far not levelled off but is increasing further. If the trend continues, the predicted incidence in Finland will be approximately 50 per 100,000 per year in the year 2010.

Regional differences in the incidence of insulin-dependent diabetes mellitus among children in Finland from 1987 to 1991. Childhood Diabetes in Finland (DiMe) Study Group.

The regional pattern of insulin-dependent diabetes mellitus (IDDM) incidence among children in Finland was analysed applying several methods attempting to describe the geographical variation in occurrence of IDDM. From 1987 to 1991 the number of newly diagnosed cases aged 14 years or less at diagnosis was 1728. The incidence, the incidence rate ratio and the Bayes relative risk (RR) for IDDM were calculated by municipality, by functional area (an urban centre with a subordinated surrounding area) and by area with a population of equal size at risk employing the Geographical Information Systems. The association of IDDM incidence with the degree of urbanization was assessed using the population density as a criterion for the degree of urbanization. The overall mean of the IDDM incidence was 35 per 100000 persons per year. Between municipalities the incidence varied from 4 to 245 per 100000 persons per year, whereas a clear regional pattern was seen among the functional areas and the incidence varied from 26 to 43 per 100000 persons per year. The RR for IDDM among the municipalities ranged from 0.82 to 1.34 and from 0.73 to 1.27 among the functional areas. The incidence determined in four zones with the same size of population was the highest in the middle part of the country. There was a strong inverse correlation between population density and the incidence of IDDM and this also applied to the relationship between child population density and incidence.

Detection of overall space-time clustering in a non-uniformly distributed population. DiMe Study Group.

We developed a test statistic based on an approach of Whittemore et al. (1987) to detect space-time clustering for non-infectious diseases. We extended the spatial test of Whittemore et al. by deriving conditional probabilities for Poisson distributed random variables. To combine spatial and time distances we defined a distance matrix D, where dij is the distance between the ith and jth cell in a three-dimensional space-time grid. Spatial and temporal components are controlled by a weight. By altering the weight, both marginal tests and the intermediate test can be reached. Allowing a continuum from a pure spatial to a pure temporal test, the best result will be gained by trying different weights, because the occurrence of a disease might show some temporal and some spatial tendency to cluster. We examined the behaviour of the test statistic by simulating different distributions for cases and the population. The test was applied to the incidence data of insulin-dependent diabetes mellitus in Finland. This test could be used in the analysis of data which are localized according to map co-ordinates, by addresses or postcodes. This information is important when using the Geographical Information System (GIS) technology to compute the pairwise distances needed for the proposed test.

Islet cell autoimmunity and progression to insulin-dependent diabetes mellitus in genetically high- and low-risk siblings of diabetic children. The Childhood Diabetes in Finland (DiMe) Study Group.

Insulin-dependent diabetes mellitus (IDDM) risk was evaluated in 765 siblings based on prospective observation of islet cell antibodies (ICAs) and insulin autoantibodies (IAAs) as a function of the degree of HLA identity to the proband and HLA-DR alleles. Twenty-eight (3.7%) siblings progressed to IDDM over a median observation period of 5.8 years. ICAs had higher sensitivity than IAAS (100% vs. 33% , P < 0.001), whereas persistent ICA positivity and double ICA/IAA positivity defined the highest actuarial risk (47% and 70%). Diabetes manifested after a mean of 3.2 years from the detection of ICAs in those siblings who were initially ICA negative and, importantly, the risk was equal to that of the siblings constantly positive from the first sample obtained. Although the combination of HLA identity and ICAs at or above 80 Juvenile Diabetes Foundation units carried the highest positive predictive value (77%), the high-risk HLA markers were insufficient to predispose siblings with low ICA levels to IDDM and low-risk HLA markers did not provide complete protection against high ICA levels and from subsequent IDDM. These results emphasize ICAs as the primary tool for risk evaluation in siblings followed by restricted HLA subtyping to reduce the population to be subjected to clinical intervention trials.

Seasonality in the clinical onset of insulin-dependent diabetes mellitus in Finnish children. Childhood Diabetes in Finland (DiMe) Study Group.

Seasonal patterns in the incidence of insulin-dependent diabetes based on 2,062 cases diagnosed at age 14 years or under in Finland are described for the years 1987-1992. Seasonal patterns were estimated presenting the data as short Fourier series up to three harmonics together with a possible linear trend. This method allows an arbitrary shape for the seasonal effect. Likelihood ratio tests and Akaike's information criterion were used to determine the number of harmonics necessary to model the seasonal pattern and to test differences among age- and sex-specific subgroups in the population. Seasonal patterns in incidence were compared between sexes and between the three 5-year age groups with each controlling for the other's effect. A significant seasonal pattern in the incidence of insulin-dependent diabetes was found for the sexes combined and for two age groups (0-9 and 10-14 years). A statistically significant seasonal pattern could be confirmed for males, but not for females. During a calendar year, one cycle with a decreased incidence of insulin-dependent diabetes in June was found among younger boys. Among older boys, there were two distinct cycles with a decreased incidence, the first in June and the second during November-December. The most visible seasonal pattern was a lower number of cases diagnosed in June, while during the rest of the year the incidence remained relatively stable and high. The average annual incidence was 35.6 per 100,000 persons without any upward peaks.