Biomedical subjects

H Oja

Publications and source records attributed to H Oja.

At least 19 recordsLinked to original sources

PubMed2000

Thought disorder index of Finnish adoptees and communication deviance of their adoptive parents.

BACKGROUND: Diverse forms of thought disorder, as measured by the Thought Disorder Index (TDI), are found in many conditions other than schizophrenia. Certain thought disorder categories are primarily manifest during psychotic schizophrenic episodes. The present study examined whether forms of thought disorder qualify as trait indicators of vulnerability to schizophrenia in persons who are not clinically ill, and whether these features could be linked to genetic or environmental risk or to genotype-environment interactions. The Finnish Adoptive Study of Schizophrenia provided an opportunity to disentangle these issues. METHODS: Rorschach records of Finnish adoptees at genetic high risk but without schizophrenia-related clinical diagnoses (N = 56) and control adoptees at low genetic risk (N = 95) were blindly and reliably scored for the Thought Disorder Index (TDI). Communication deviance (CD), a measure of the rearing environment, was independently obtained from the adoptive parents. RESULTS: The differences in total TDI between high-risk and control adoptees were not statistically significant. However, TDI subscales for Fluid Thinking and Idiosyncratic Verbalization were more frequent in high-risk adoptees. When Rorschach CD of the adoptive rearing parents was introduced as a continuous predictor variable, the odds ratio for the Idiosyncratic Verbalization component of the TDI of the high-risk adoptees was significantly higher than for the control adoptees. CONCLUSIONS: Specific categories of subsyndromal thought disorder appear to qualify as vulnerability indicators for schizophrenia. Genetic risk and rearing-parent communication patterns significantly interact as a joint effect that differentiates adopted-away offspring of schizophrenic mothers from control adopted-away offspring.

Adolescent↗

PubMed1997

Is a child's risk of early onset schizophrenia increased in the highest social class?

In a sample from the unselected, general population Northern Finland 1966 Birth Cohort, 11017 individuals alive at the age of 16 years were studied until the age of 27. The cumulative incidence of early onset schizophrenia until 23 years was higher (1.14%; 9/792) among young persons from the highest social class or class I (determined according to father's occupation) than among children from lower social classes (0.47%; 48/10225), the difference being statistically significant (p < 0.05). The incidence of schizophrenia in the highest social class was higher than expected among girls, firstborns, children of young mothers under 30 and urban residents (p < 0.05) compared with lower social classes. When cases from the highest and other social classes were compared, there was no clear difference in background factors or clinical course. Four alcoholics, one of them also schizophrenic, were found among nine social class I fathers. The results suggest that in some families in Northern Finland, a father's professional advancement, often linked to mental disorder, may be one determinant of an increased risk of schizophrenia in the child.

Adolescent↗

PubMed1997

Gene-environment interaction in vulnerability to schizophrenia: findings from the Finnish Adoptive Family Study of Schizophrenia.

OBJECTIVE: This study assessed the interaction of genetic risk and rearing-family risk as a subsyndromal test measure of schizophrenic thought disorder in adoptees. METHOD: A group of 58 adoptees with schizophrenic biological mothers was compared with 96 comparison adoptees at ordinary genetic risk; putative adoptee vulnerability was assessed blindly and reliably by using the Rorschach Index of Primitive Thought. Environmental risk was measured by using frequency of communication deviance as a continuous variable, scored independently from Rorschach assessments of the adoptive parents. RESULTS: High genetic risk in itself was not associated with greater vulnerability to schizophrenic thought disorder in the adoptees, as indicated by the Index of Primitive Thought. Also, greater communication deviance in the adoptive parents was not associated with greater thought disorder in the comparison adoptees. However, there was a highly significant gene-environment interaction. Among the offspring of the adoptive parents with high levels of communication deviance, a higher proportion of high-risk than comparison adoptees showed evidence of thought disorder. In contrast, among the offspring of adoptive parents with low communication deviance, a lower proportion of high-risk than comparison adoptees showed evidence of thought disorder. The distribution of communication deviance scores did not differ significantly between the adoptive parents of high-risk offspring and the adoptive parents of comparison offspring. CONCLUSIONS: The findings are consistent with genetic control of sensitivity to the environment. There is no evidence that high genetic risk of schizophrenia among offspring is associated with high levels of communication problems in rearing parents.

Adoption↗

PubMed1997

Physiological fluctuations in nasal resistance may interfere with nasal monitoring in the nasal provocation test.

The physiological fluctuations in nasal flow and resistance in allergic subjects were studied by monitoring 12 subjects with perennial occupational allergic rhinitis with active anterior rhinomanometry (AAR) for 3 h at 15 min intervals. The subjects were then challenged bilaterally with the diluent solution for allergen extracts and the effect was monitored with AAR. In AAR. cellular rubber nose adapters were used. Many physiological fluctuations in nasal patency were observed. Reference intervals were calculated for the changes in flow and resistance at the gradient pressure of 150 pa. For example, a 100% increase in unilateral resistance was found to be significant at the risk level of 5-10% for the observation time of 30-60 min. The corresponding increase for bilateral resistance was close to 70%. Challenge with diluent solution had a negliglible effect on the resistance fluctuation, the reference intervals being close to those for baseline monitoring. In conclusion, rapid changes in nasal flow and resistance in allergic subjects were common, and caution is necessary when interpreting these changes as a positive nasal reaction in the nasal provocation test. In addition, the use of other objective parameters, such as the amount of nasal secretion is recommended.

Adult↗

PubMed1997

Prevalence figures for mild hearing impairments cannot be based on clinical data.

The target population of the present study consisted of a 1-year (July 1985-June 1986) birth cohort from northern Finland. The prevalence of even slight hearing impairments (any threshold from 0.5 to 4 kHz > or = 25 db) at the age of 7 years was investigated among those 8,713 children still living in the area. The subjects for clinical audiometry were obtained in two ways. First, the standard clinical practice brought about 541 children, either with non-confirming results from their child welfare clinic screenings, suspected by their parents or already diagnosed as hearing impaired at a hospital. Secondly, in addition to this group, a random sample of 1,009 children, out of the 8,172 children not suspected, were also invited for audiometry. Of the clinical material, 101 children out of the 438 investigated were found to have impaired hearing according to the above criteria, and another 27 children out of the 789 investigated were obtained from the random sample. The estimated over-all prevalence of hearing impairments, even with the slight ones included, turned out to be 3.9% (95% confidence interval, CI, 2.7-5.7). Only 32% of the hearing impairments could be obtained according to the standard clinical policy! In conclusion, one cannot rely on clinical data when calculating prevalence figures for mild hearing impairments.

Audiometry↗

PubMed1996

Model-based estimation of the excess fraction (attributable fraction): day care and middle ear infection.

The methods of adjustment for estimation of the excess fraction (EF), or attributable fraction, based on conventional and dynamic (or regressive or autoregressive) logistic regression modelling in a cohort study for a disease with recurrent episodes are considered. Throughout the paper, the computation of estimates with corresponding confidence intervals is illustrated in a cohort study associating the incidence of acute middle ear infection (acute otitis media) with type of day care in northern Finland. The incidences of at least one episode and at least three episodes as well as the total number of episodes during the first two years of life are considered. In our example, the estimates obtained from the dynamic model appear to have smaller standard errors since the dynamic model effectively utilizes the time-dependency of the covariates.

Child Day Care Centers↗

PubMed1996

Public health impact of various risk factors for acute otitis media in northern Finland.

The aim of this study was to assess the excess risk attributable to alterable risk factors for acute otitis media in Finnish children, including day care attendance, parental smoking, and a short duration of breastfeeding. Data on a population-based cohort of 2,512 children were gathered from medical records and questionnaires from 1985 to 1988. Excess (attributable) fractions for the risk factors were calculated among 825 children (target population) followed for 2 years, from a dynamic logistic model fitted to the entire cohort (estimation data). In theory, one child out of every five affected in the exposed population would have escaped otitis media completely if he/she had been moved from nursery day care to home care, and two out of every five affected could have escaped recurrent episodes in this way. The corresponding figures for family day care were lower: one and two children out of every six affected, respectively. Cessation of parental smoking and breastfeeding would have smaller effects. The impacts were more modest in the whole population. Nevertheless, approximately 14% of all of the otitis media episodes would have been avoided if all of the children had been cared for at home. These figures are hypothetical, since it is unlikely that use of day care outside the home can be avoided altogether, but they offer further evidence of the notable role of day care attendance as a risk factor for otitis media.

Acute Disease↗

PubMed1996

How should relative risk estimates for acute otitis media in children aged less than 2 years be perceived?

To determine how the effects of certain risk factors for acute otitis media (AOM) vary according to the values of other risk determinants, and thus to obtain risk estimates more applicable to individual children, the medical records of a random sample of 2,512 children in northern Finland were monitored for the disease for up to an average age of 22 months. Information on determinants of AOM was obtained from parental questionnaires. The risk of the first AOM episode and that of later episodes were modelled separately by logistic regression using time-dependent values for some determinants. The odds ratio (OR) estimates for the alterable risk factors varied markedly over categories of other determinants as follows: nursery day care versus home care (OR from 1.1 to 3.0), parental smoking (OR from 0.9 to 1.5), and breast-feeding (OR from 0.5 to 1.0). Hence, to assess the significance of each risk factor for an individual child, the values for other relevant factors must be considered concurrently.

Acute Disease↗

PubMed1996

Dynamic multivariate modelling: day care and consultation rate for acute otitis media.

A random sample of 2,512 children was monitored to the age of 2 years to study the effects of various risk variables on the consultation rate of acute otitis media. A total of 3,283 episodes of acute otitis media of 2,411 children with a follow-up time of at least 1 month were included in the analysis. During a 3 week-period after onset of the episode, the number of unplanned visits varied between 0 (2,544 episodes; 77.5%) and 6 (2 episodes; 0.1%). The children with day care outside their home showed a diminished risk for unplanned visits during the first week. The odds ratio (OR) and 95% confidence interval (CI) for children in family day care were 0.58 and 0.39-0.8, and 0.72 and 0.47-1.11 for children in nursery day care, respectively. During the second and third weeks the results were reversed: the above odds ratios should be multiplied by interaction terms 2.19 (CI 1.41-3.42; new OR 1.27) for children in family day care and 1.57 (CI 0.97-2.54; new OR 1.13) for children in nursery day care.

Acute Disease↗

PubMed1996

What is the natural history of recurrent acute otitis media in infancy?

BACKGROUND: Chemoprophylaxis or tympanostomy tubes are often recommended for recurrent acute otitis media because of the associated morbidity, temporary hearing loss, financial costs, and risks of middle-ear sequelae. The aim of this study was to study the natural course of recurrent acute otitis media in infancy without such prophylactic treatment. METHODS: Two hundred twenty-two children who had recurrent acute otitis media and received no prophylaxis were monitored for subsequent acute otitis media and the development of chronic otitis media with effusion. RESULTS: Only 4% of the 222 infants with recurrent acute otitis media developed chronic otitis media with effusion and an additional 12% continued having recurrent episodes. The most significant factor predicting an increased risk of recurrence was young age (< 16 months of age). Attending day care and having siblings had a less pronounced effect. CONCLUSIONS: Spontaneous recovery from recurrent acute otitis media is common with increasing age. Thus, until reliable causal evidence between recurrent otitis media and developmental disability is presented, chemoprophylaxis or tympanostomy tubes seem superfluous for most infants after the age of 16 months.

Acute Disease↗

PubMed1995

Chronic otitis media with effusion in infancy. How frequent is it? How does it develop?

OBJECTIVE: To study the occurrence and development of chronic otitis media with effusion in infancy. DESIGN: A retrospective birth cohort with a 2-year follow-up. Infection data were gathered from medical records; background information came from questionnaires. SETTING: Primary health care centers, hospitals, and private practices in 10 randomly selected local government districts in the two northernmost provinces of Finland. SUBJECTS: A random sample of 2512 children from the cohort. MAIN OUTCOME MEASURES: Chronic otitis media with effusion determined as a minimum of 2 months of asymptomatic middle ear effusion revealed by tympanocentesis and specific operative findings. RESULTS: The periodic prevalence rate of chronic otitis media with effusion up to the age of 24 months was 4.4% (95% confidence interval, 3.5 to 5.3). The maximum risk was at age 16 months. The number of acute otitis media episodes among children who developed chronic otitis media with effusion was more than double that of normal healthy children before the onset of chronic inflammation and about five times as high during prolonged mucous middle ear effusion. Inadequate treatment of prior acute otitis media was not the reason for the chronic inflammation, which was a direct continuation of an acute episode in only half of the cases and was otherwise preceded by a latent period of varying duration. CONCLUSIONS: Chronic otitis media with effusion, which may cause adverse developmental effects such as delayed language development, is a fairly common disease in infancy and is closely related to acute otitis media episodes.

Acute Disease↗

PubMed1995

Risk factors for chronic otitis media with effusion in infancy. Each acute otitis media episode induces a high but transient risk.

OBJECTIVE: To examine the effects of a history of acute otitis media and different extrinsic factors on the risk of chronic otitis media with effusion in infancy. DESIGN: A retrospective birth cohort with a 2-year follow-up. Infection data were gathered from medical records and background information came from questionnaires. The monthly risk of chronic otitis media with effusion was dynamically modeled to control the confounding effects and time-dependency of the risk factors. SETTING: Primary health care centers, hospitals, and private practices in 10 randomly selected local government districts in the two northern most provinces of Finland. SUBJECTS: A random sample of 2512 children from the cohort. MAIN OUTCOME MEASURES: Chronic otitis media with effusion, defined as a minimum of 2 months of middle-ear effusion, usually is disclosed by tympanocentesis and specific operative findings. RESULTS: Previous acute otitis media episodes were the greatest risk factor. Each acute episode induced a highly increased risk (odds ratio, 11.9; 95% confidence interval, 5.7 to 24.9) that disappeared in 3 months. Successive episodes were risky, but this risk also decreased rapidly. Other significant risk variables were attendance at a day nursery (odds ratio, 2.56; confidence interval, 1.17 to 5.57), male sex (odds ratio, 2.17; confidence interval, 1.37 to 3.44), and autumn season (odds ratio, 1.99; confidence interval, 1.11 to 3.55). CONCLUSIONS: Acute otitis media episodes constitute the greatest risk of chronic otitis media with effusion. Each episode has a high transient risk for 3 months but no further direct effect on the risk.

Acute Disease↗

PubMed1995

Acute epiglottitis and infant conjugate Haemophilus influenzae type b vaccination in northern Finland.

OBJECTIVE: To determine the incidence and characteristics of acute epiglottitis among children (< or = 19 years of age) and adults (> or = 20 years of age) before and after widespread conjugate Haemophilus influenzae type b vaccination for infants. DESIGN: A retrospective population-based survey over a 27-year period from 1967 through 1993 in 35 communities in a northern province of Finland with a population of approximately 300,000. SETTING: An academic tertiary referral center. MAIN OUTCOME MEASURES: All acute epiglottitis cases in the area identified from the hospital discharge register and the regional autopsy register. RESULTS: The average incidence rate for children was 1.8 cases per 100,000 individuals per year (95% confidence interval [CI], 1.3 to 2.5). As no vaccine failures emerged, the incidence rate for children aged 0 to 4 years declined sharply once the vaccination started in 1986 from 7.6 (95% CI, 5.3 to 10.4) to 0 (95% CI, 0 to 3.3) cases per 100,000 individuals per year. By contrast, a fourfold increase in adult acute epiglottitis (incidence rate ratio, 4.6; 95% CI, 2.7 to 7.9) was detected after vaccination of the children, the average incidence rate for the whole period being 1.0 cases per 100,000 individuals per year (95% CI, 0.8 to 1.3). No marked change in the adult patient profile was found during this increase, however. CONCLUSION: Acute epiglottitis practically vanished among young children in this population after conjugate H influenzae vaccination, but adult cases increased, the patient profile remaining the same.

Acute Disease↗

PubMed1995

Smoking or quitting during pregnancy: associations with background and future social factors.

Current and future social factors associated with smoking habits during pregnancy were assessed. Data on maternal smoking, social background and the family's development during the 21 years after delivery were gathered for a prospective longitudinal cohort study of 12,068 pregnant women and their children in Northern Finland in 1966 and for a second birth cohort of 9,362 mothers in 1985-86. The prevalence of smoking before pregnancy was 22% in the 1966 cohort (29% in 1985-86). 12% (18%) of the women continued smoking throughout their pregnancy. The following background factors were mainly associated with the mother's smoking and/or continuing during pregnancy in both cohorts when mother's age, parity, place of residence and social class were standardized: mother's age under 23, parity two or more, low social class, urban dwelling, unmarried, gainful employment and heavy smoking. The follow-up responses after 14 and 21 years, respectively, were mostly more favourable among the non-smoking mothers and those who quit smoking during pregnancy-e.g. stable family structure, child's smoking and drinking habits and application for intermediate education. Smoking throughout pregnancy or quitting of smoking late in pregnancy were associated with undesirable future development of the child and family in most of these aspects.

Female↗

PubMed1994

Which children are being operated on for recurrent acute otitis media?

OBJECTIVE: To examine at the population level which children were operated on for recurrent acute otitis media episodes, how ill they were, and what factors affected the operation rate. DESIGN: A retrospective birth cohort with an approximate 2-year follow-up. Infection data were gathered from medical records, and background information was gathered from questionnaires. SETTING: Primary health care centers, hospitals, and private practices in 10 randomly selected local government districts in the two northernmost provinces of Finland. SUBJECTS: A random sample of 2512 children from the cohort. OUTCOME MEASURES: Adenoidectomy and/or tympanostomy tube insertion. RESULTS: Only one of 10 of those with actual recurrent disease (> or = 4 episodes) had been operated on, and three of every five children operated on, in fact, had rather few episodes. The operation rate among those children with only a few episodes was increased by factors such as consulting an ear, nose, and throat specialist (risk ratio [RR], 13.0; 95% confidence interval [CI], 7.6 to 22.2); parental exaggeration of the episodes (RR, 6.7; 95% CI, 3.8 to 11.9); having the first episode under 6 months of age (RR, 4.5; 95% CI, 2.5 to 7.9); recurrent respiratory tract infections (RR, 3.3; 95% CI, 1.9 to 5.7); male sex (RR, 2.6; 95% CI, 1.4 to 4.6); urban domicile (RR, 2.4; 95% CI, 1.1 to 4.9); and day care (RR, 2.1; 95% CI, 1.1 to 3.8). The decision to operate was more or less a random phenomenon among those children with numerous episodes. CONCLUSIONS: Physicians at the primary care level should be familiar with these pitfalls concerning patient selection so that the operations are targeted at those children who are most seriously ill.

Acute Disease↗

PubMed1994

Teenage alcohol drinking and non-standard family background.

The teenage alcohol drinking in 1980 is described in a cohort of 12,058 subjects born in Northern Finland in 1966, with special reference to non-standard families (with one or both parents absent). The percentage of boys (girls) who had been drinking alcohol at the age of 14 years, was 59.1 (58.3)%, being 57.5 (55.6%) in standard, full families and 66.0 (69.0)% in non-standard families. The percentage of having been drunk was 25.2 (25.1)%, or 22.8 (22.1)% in full families and 36.1 (37.1)% in the non-standard families. When adjusted for the maternal age at birth, place of residence, social class and child's status in the family (firstborn or not, only child or not) by means of regression modelling, the risk of alcohol drinking/having been drunk was still increased in non-standard families, especially in cases of divorce or same-sex parental death, the risk differences as compared to the standard family usually being between 10-20%. The results suggest that a non-standard family structure is associated with early juvenile alcohol drinking. Parental loss or absence may constitute one important factor leading to excessive haste in adopting the adolescent culture, including its potentially destructive habits.

Adolescent↗

PubMed1994

Changes in risk factors for unfavorable pregnancy outcome among singletons over twenty years.

OBJECTIVES: To examine the change in the prevalence and relative effect of pre-pregnancy risk factors for low birthweight and/or stillbirth and/or neonatal mortality over a period of twenty years. DESIGN: Two prospectively collected one year birth cohorts. SETTING: The two northernmost administrative districts of Finland. PATIENTS: A birth cohort for 1966 comprising 11905 singleton births and a cohort for 1985-86 containing a further 9247. MAIN OUTCOME MEASURES: Risk factors for poor pregnancy outcome. RESULTS: In twenty years the prevalence of low birthweight infants among singletons decreased from 4.2% to 3.1% and that of stillbirths and neonatal deaths from 2.4% to 0.9%. The impact of single marital status decreased and while maternal age < 19 years was not an independent risk factor, the age > or = 35 years related more to poor pregnancy outcome. The proportion of multiparous women was halved but multiparity had a protective influence on pregnancy outcome meanwhile the impact of primiparity decreased markedly. In spite of more effective health education, the prevalence of heavy smokers was 4 times higher in the 1980s as compared with the 1960s, and its impact on adverse outcomes increased, with odds ratio (OR) 1.72 (confidence interval (CI) 1.14-2.61) in 1966 and OR 2.15 (CI 1.61-2.88) in 1985-86. The number of mothers with a previous low birthweight baby was halved but the impact of low birth weight was still great in the latter cohort (OR 2.47; CI 1.64-3.71). The impact of an earlier stillbirth and/or neonatal death increased significantly, with an OR 1.53 (CI 1.10-2.14) in 1966 and OR 2.95 (CI 1.81-4.81) in 1985-86, but the number of mothers concerned was halved from that in 1966. CONCLUSIONS: The prevalence of pregnancies with an adverse outcome decreased markedly, as did the prevalence of many of the risk factors. The proportion of > or = 35 years old parturients and of heavy smokers increased. The impact of primiparity decreased, while that of a previous outcome as assessed from pre-pregnancy factors has not improved in these twenty years, especially where primiparous parturients are concerned.

Adult↗

PubMed1993

Control of the temporal aspect when considering risk factors for acute otitis media.

A random sample of 2512 children was monitored to age 2 years to study the biologic effects of various risk variables on acute otitis media using a new dynamic modeling that controls both the confounding effects and time dependency. Dynamic modeling proved to be superior to conventional approaches, both the random and systematic error being much smaller and the effect estimates being biologically interpretable. The major risk factors were the existence of a previous episode of acute otitis media in general (odds ratio, 2.03; 95% confidence interval [Cl], 1.81 to 2.25) or particularly during the preceding 3 months (odds ratio, 3.74; 95% Cl, 3.40 to 4.10) and attending a day nursery (odds radio, 2.06; 95% Cl, 1.81 to 2.34). As the form of day care is the only modifiable risk variable of significant importance and previous episodes entail a risk of future ones, infants should be cared for at home, particularly after they have already experienced an episode of acute otitis media.

Acute Disease↗