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Biomedical subjects

H Oja

Publications and source records attributed to H Oja.

33 records · Page 2Linked to original sources
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↗
PubMed1993

The relation between teenage smoking and drinking, with special reference to non-standard family background.

Associations between simultaneous teenage drinking and smoking are considered in a birth cohort born in Northern Finland in 1966 (n = 12,058), especially in non-standard, mainly single parent families. Data were collected from pregnancy until the age of 14. ROC (receiver operating characteristic curve) analysis was used to assess how well smoking predicts use of alcohol. Smoking and drinking were more interconnected in the non-standard families among both boys (p = 0.007) and girls (p = 0.018), but only among boys (p = 0.064) when the data were standardized for social class and place of residence and not among girls (p = 0.191). A similar relation between smoking and having been drunk was found among boys in non-standard families (p = 0.016), even when adjusted as above (p = 0.029), but not among girls (unadjusted p = 0.235, adjusted p = 0.469). The findings suggest that the adolescent boy's self-protective behaviour with respect to the commencement of combined experimentation with smoking and drinking is more restricted in non-standard families than in standard families.

Adolescent↗
PubMed1992

Perinatal outcome of pregnancies complicated by vaginal bleeding.

OBJECTIVE: To examine the effect of first and/or second trimester vaginal bleeding on pregnancy outcome. DESIGN: A prospective one-year birth cohort. SETTING: Two northernmost administrative districts of Finland. PATIENTS: 8718 singleton pregnancies, of whom 807 (9.3%) reported bleeding during the first (601) and/or second trimester (206); light bleeding in 595 cases and heavy bleeding in 212. The remaining 7911 women served as a reference group. MAIN OUTCOME MEASURES: Low birth weight rate (LBW), preterm birth rate, congenital malformations and perinatal mortality rate. RESULTS: Bleeding was most frequent in women of more advanced age (> or = 35 years old), with previous miscarriages, with infertility problems or using an IUCD prior to the pregnancy. Parity, smoking and social status were not associated with bleeding. Caesarean section rate and placental complications during the third trimester and at delivery were more common among the bleeders than in the reference group. The LBW rate was three-fold among the bleeders and the preterm birth rate two-fold. The risk (OR) of a LBW infant among second trimester bleeders was 4.1 (95% CI 2.6-6.4), that of preterm birth 2.9 (95% CI 1.9-4.6), and that of congenital malformations 2.9 (95% CI 1.7-4.7). No association existed between bleeding and perinatal mortality. CONCLUSIONS: Bleeding during the second trimester indicates a poor pregnancy outcome and an increased risk of LBW, and preterm birth and/or congenital malformation.

Adult↗
PubMed1991

Fitting mixture models to birth weight data: a case study.

Birth weights by gestational age are compared in two birth cohorts from Northern Finland, the first from 1966 and the second from 1985-1986. A curious fact in the data is that mean birth weight before the 39th week was lower in the latter series although the mean birth weight for the total series was higher. Similar findings have been reported in other series. A mixture model with the nonparametric regression function is proposed for studying the hypothesis that the difference was caused by more frequent gross errors in gestational assessment in the earlier cohort. The probability of an error in gestational assessment then greatly depends on the observed gestational age, which makes the mixture model nonstandard. Maximum likelihood solutions to the parameters in the proposed model were computed employing the general expectation-maximization (EM) algorithm. A technique for studying the effect of errors on the intrauterine weight gain curve is proposed and applied to our two birth cohorts. The risk of underestimation of gestational age seems to be larger in the previous series and the differences between the growth curves almost totally vanish when "corrected" by means of the mixture model.

Algorithms↗
PubMed1990

Perinatal risk for infants of unmarried mothers over a period of 20 years.

The perinatal events of the infants of 444 unmarried mothers, 3.7% of the total Northern Finland birth cohort from 1966, were compared with those of infants of 11,525 married mothers (95.5%), and a similar comparison was made between 395 (4.2%) unmarried mothers and 7516 (80.3%) married mothers in a second Northern Finland birth cohort in 1985-86. 1336 mothers, 14.3% of the mothers in this later cohort, were cohabiting. Divorced and widowed mothers were excluded from both cohorts. The infants of the unmarried mothers had a significantly lower mean birth weight, were more likely to be small for their gestational age (SGA), of low birth weight (LBW) (below 2500 g) and had a higher incidence of pre-term births than those of the married mothers in both cohorts. Perinatal mortality was significantly higher among the unmarried mothers only in the former cohort. These differences in perinatal events diminished markedly after adjustment for maternal age, parity, height, years of schooling and smoking habits, but did not totally disappear. The difference in the incidence of pre-term births diminished, but remained significant in both cohorts. The difference in mean birth weight, in the incidence of LBW infants and in perinatal mortality remained significantly less favourable to the unmarried mothers only in the 1966 cohort. It seems that the gap between the married and unmarried mothers had diminished. The incidence of SGA infants did not differ significantly between the married and unmarried mothers in either cohort after adjustment for the background variables. The cohabiting mothers formed an intermediate group between the married and single unmarried mothers in respect of perinatal events, but were close to the married mothers. In raw figures, the mean birth weight in this group was significantly lower and the incidence of SGA infants higher than among the married mothers, but these differences also disappeared after adjustment of the background variables.

Body Height↗