Retrospective and prospective study designs

The labels "retrospective" and "prospective" strongly connote study quality, often favouring prospective studies. However, three definitions of these terms exist, each suggesting distinct methodological limitations. In this review, we summarize and evaluate these definitions. Caution is warranted when labeling a study "retrospective": This label should only be used when implying a risk of recall bias, which can only occur in retrospective data collection. Generally, assessing random and systematic errors is necessary to appraise study quality rather than relying on ambiguous labels.

Preadmission Opioid Use and 1-Year Mortality Following Incident Myocardial Infarction: A Danish Population-Based Cohort Study (1997-2016)

Background Opioid use has been linked to an increased risk of myocardial infarction and cardiovascular mortality, but the prognostic impact of opioid use before an incident myocardial infarction is largely unknown. Methods and Results We conducted a nationwide population-based cohort study including all patients hospitalized for an incident myocardial infarction in Denmark (1997-2016). Based on their last redeemed opioid prescription before admission, patients were categorized as current users (0-30 days), recent users (31-365 days), former users (>365 days), and nonusers. One-year all-cause mortality was calculated using the Kaplan-Meier method. Hazard ratios (HRs) were computed using Cox proportional hazards regression analyses, adjusting for age, sex, comorbidity, any preceding surgery within 6 months before the myocardial infarction admission, and medication use before the myocardial infarction admission. We identified 162 861 patients with an incident myocardial infarction. Of these, 8% were current opioid users, 10% were recent opioid users, 24% were former opioid users, and 58% were nonusers of opioids. One-year mortality was highest among current users (42.5% [95% CI, 41.7%-43.3%]) and lowest among nonusers (20.5% [95% CI, 20.2%-20.7%]). Compared with nonusers, current users had an elevated 1-year all-cause mortality risk (adjusted HR, 1.26 [95% CI, 1.22-1.30]). Following adjustment, neither recent users nor former users of opioids were at elevated risk. Conclusions Preadmission opioid use was associated with an increased 1-year all-cause mortality risk following an incident myocardial infarction. Opioid users thus represent a high-risk subgroup of patients with myocardial infarction.

Long-Term Outcomes of Perioperative Versus Nonoperative Myocardial Infarction: A Danish Population-Based Cohort Study (2000–2016)

Background:

Perioperative myocardial infarction is a serious cardiovascular complication of noncardiac surgery. The clinical course of perioperative myocardial infarction, other than all-cause mortality, is largely unknown. We examined long-term fatal and nonfatal outcomes of perioperative myocardial infarction compared with nonoperative myocardial infarction.

Methods:

We conducted a population-based cohort study of first-time myocardial infarction in Denmark from 2000 to 2016. We calculated cumulative incidence of all-cause mortality, cardiac mortality, recurrent myocardial infarction, heart failure, stroke, venous thromboembolism, acute kidney injury, and kidney failure with replacement therapy. We computed 5-year risk ratios adjusted for age, sex, year of diagnosis, educational level, and comorbidities.

Results:

We identified 5068 patients with perioperative myocardial infarction and 137 862 patients with nonoperative myocardial infarction. The 5-year risk of all-cause mortality was 67.5% (95% CI, 66.1%–69.0%) for perioperative myocardial infarction patients and 38.0% (95% CI, 37.7%–38.3%) for nonoperative myocardial infarction patients. The adjusted risk ratio of all-cause mortality was 1.13 (95% CI, 1.11–1.16) at 5 years. After adjustment, we found no association between patients with perioperative myocardial infarction and 5-year cardiac mortality, recurrent myocardial infarction, heart failure, stroke, or kidney failure with replacement therapy when compared with nonoperative myocardial infarction patients. Perioperative myocardial infarction patients had a higher relative risk of venous thromboembolism (5-year risk ratio, 1.21 [95% CI, 1.01–1.46]) and acute kidney injury (5-year risk ratio, 1.37 [95% CI, 1.22–1.53]).

Conclusions:

Compared with nonoperative myocardial infarction patients, perioperative myocardial infarction patients had elevated risk of all-cause mortality, venous thromboembolism, and acute kidney failure. In addition to the myocardial infarction component of perioperative myocardial infarction, this poor prognosis seemed associated with the surgery or underlying comorbidities. These findings warrant further research on strategies to reduce the risk of perioperative myocardial infarction and on strategies to manage perioperative myocardial infarction.

Breaking Point Toward Decreasing Prevalence of Myocardial Infarction Owing to Relative Stronger Decrease in Incidence Than Increase in Survival Rate (A Danish Cohort Study [1994-2016])

The aim of this study was to examine whether myocardial infarction (MI) incidence rate continues to decrease and to determine whether the relative magnitude of a potentially decreasing incidence rate has surpassed increasing survival, demasking a breaking point in trends of MI prevalence proportion. This was a nationwide population-based cohort study using medical registries covering all hospitals in Denmark (1994 to 2016). We identified 193,870 persons with a first-time hospitalization for MI. Age-standardized incidence rates (per 100,000 persons) decreased from 154 (95% confidence interval [CI] 149 to 159) in 1994 to 90 (95% CI 86 to 93) in 2016 for females, and from 335 (95% CI 326 to 344) in 1994 to 205 (95% CI 199 to 211) in 2016 for males. Age-standardized prevalence proportion increased overall from 1994 to 2004 with a subsequent plateau. From 2006 to 2016, age-standardized prevalence proportion decreased by 0.09% (95% CI 0.07% to 0.11%) for females (from 1.07% to 0.98%) and by 0.20% (95% CI 0.17% to 0.23%) for males (from 2.85% to 2.65%). The age-standardized prevalence proportion decreased solely among persons aged 55 to 84 years. It remained stable among persons aged <55 years and increased among persons aged ≥85 years until 2012 with subsequent stable trends. We conclude that the continuous decreasing age-standardized incidence rate of MI over decades has, although with increasing survival, led to an overall breaking point toward a decreasing age-standardized prevalence proportion of MI since 2006.

Impact of the Look-Back Period on Identifying Recurrent Myocardial Infarctions in the Danish National Patient Registry

Purpose

Studies examining myocardial infarction (MI) often seek to include only incident MIs by excluding recurrent MIs. When based on historical data, identification of previous MI depends on the length of the look-back period. However, international registries often cover a short time period, consequently containing left-censored data, making it impossible to determine if a first MI in a period is truly an incident MI. We evaluated whether the proportion of MIs identified as recurrent MIs depends on the look-back period, and how including recurrent MIs in a planned incident MI cohort impacts survival estimates.

Patients and Methods

We used the Danish National Patient Registry, covering all Danish hospitals since 1977 to identify first MIs during 2010–2016 (index events). The hospital registry history preceding the index event was then searched for previous MIs. We plotted the proportion of index events identified as recurrent MIs as a function of the look-back period. Moreover, we calculated 5-year all-cause mortality and confidence intervals (CIs) using the 1-Kaplan–Meier method for five cohorts based on the index events and defined by look-back periods of 0, 5, 10, 20, and up to 39 years.

Results

Among 63,885 index events, 3.4% were identified as recurrent MIs with 5 years of look-back, 7.9% with 10 years, 14% with 24 years, and 15% with up to 39 years. All-cause mortality risk was 36% (95% CI: 36–37%) with 0 years of look-back, 35% (95% CI: 35–36%) with 5 years, 35% (95% CI: 35–36%) with 10 years, 34% (95% CI: 34–35%) with 20 years, and 34% (95% CI: 33–34%) with up to 39 years.

Conclusion

Most recurrent MIs were identified with a look-back period of 24 years. Including recurrent MIs in a planned incident MI cohort, due to shorter look-back periods, overestimated the mortality risk.

The St. Hans Rating Scale for extrapyramidal syndromes: reliability and validity

The St. Hans Rating Scale (SHRS) is a multidimensional rating scale for the evaluation of neuroleptic-induced hyperkinesia, parkinsonism, akathisia and dystonia. This scale and the Abnormal Involuntary Movement Scale (AIMS) were tested by 7 raters (2 experienced, 2 less experienced and 3 totally inexperienced) in 30 psychiatric patients with tardive dyskinesia (TD). The test was performed 3 times in the same patients: 1) live evaluation during a video recording, 2) evaluation 2 weeks later from the videotape, and 3) evaluation after another 2 weeks from the same videotape. The intrarater reliability was high in the experienced group (0.91-0.96 for SHRS hyperkinesia scale, 0.80-0.84 for AIMS, and 0.82-0.97 for SHRS total parkinsonism). No significant changes occurred from live to video evaluation. The interrater reliability coefficient for the experienced group was also high: 0.89-0.95 for the SHRS hyperkinesia scale, 0.76-0.85 for the AIMS scale and 0.95-0.98 for the SHRS parkinsonism scale. The less experienced and the inexperienced raters had coefficients for intra- and interrater reliability that were 0.10 and 0.20 lower, respectively. The SHRS parkinsonism scale had a high construct validity, as determined by the homogeneity coefficients of Cronbach (0.82) and Loevinger (0.43). The corresponding coefficients for the hyperkinesia scales were low, in agreement with the individual distribution of TD (only about 50% present extremity dyskinesia and less than 25% facial, head and trunk dyskinesia, independent of the severity of the syndrome). Finally, convergent validity was found between the SHRS hyperkinesia scale and AIMS and divergent validity between all of the other scales.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of citalopram, a specific serotonin uptake inhibitor, in tardive dyskinesia and parkinsonism

Serotonin (5-HT) has been proposed to exert an inhibitory effect on central dopamine activity, so increased brain 5-HT would be expected to reduce tardive dyskinesia (TD). Therefore a new antidepressant, a selective 5-HT uptake inhibitor, citalopram, was evaluated in 13 psychiatric patients with TD, 11 of whom also had neuroleptic-induced parkinsonism. Drug effects during active treatment (20-40 mg/day for 3 weeks) and pre- and posttreatment placebo periods were scored blindly from videotapes recorded weekly. TD, parkinsonism, and eyeblinking rates were unchanged. Psychiatric symptoms showed no significant changes, and no side effects were reported. The data suggest that increasing 5-HT activity by 5-HT uptake inhibitors has no significant beneficial effect in TD, but citalopram may be advantageous in the treatment of depressed patients who also have TD, as this drug does not aggravate TD as do tricyclic antidepressants.

Effects of serotonergic and anticholinergic drugs in haloperidol-induced dystonia in Cebus monkeys

In rodents, serotonin (5-HT) antagonists counteract behavioral and biochemical effects of neuroleptic drugs. Therefore, we have studied the effect of different 5-HT drugs and one anticholinergic drug in acute dystonia in five cebus monkeys chronically treated with haloperidol. Acute dystonia induced by subcutaneous injections of haloperidol was slightly reduced by the 5-HT antagonist methysergide (4.0 mg/kg), while mianserin, ketanserin, and ritanserin (R 55 667; a new selective and potent 5-HT receptor blocker) had no effect. This was contrasted by the marked antidystonic effect of the anticholinergic drug biperiden (0.05-1.0 mg/kg). The 5-HT agonist citalopram, a specific 5-HT uptake inhibitor, had no significant effect. It is concluded that 5-HT antagonists have no useful effect in neuroleptic-induced dystonia.

Effects of mianserin in neuroleptic-induced parkinsonism

It has been proposed that serotonin (5-HT) antagonists counteract neuroleptic-induced extrapyramidal symptoms by disinhibition of dopamine activity. The effects of the 5-HT antagonist mianserin, the anticholinergic drug procyclidine and placebo were evaluated in 16 psychiatric patients with chronic neuroleptic-induced parkinsonism in a double-blind cross-over trial. The patients received each drug in random order in 3-week periods separated by washout periods of 2 weeks. The effect of mianserin did not significantly differ from that of placebo, while parkinsonian symptoms were significantly reduced during treatment with procyclidine (P less than 0.05). Although mianserin was ineffective in chronic neuroleptic-induced parkinsonism, it cannot be excluded that 5-HT antagonists may be effective in the treatment of acute extrapyramidal side effects.

Behavioral aspects of serotonin-dopamine interaction in the monkey

The effects of serotonin (5-hydroxytryptamine; 5-HT) antagonists and 5-HT uptake inhibitors on the behavioral response to amphetamine and haloperidol in monkeys (cercopithecus aethiops) were investigated. Amphetamine increased locomotor activity and reactivity and induced repetitive movements of head, limbs and trunk, but no oral hyperkinesia. Haloperidol induced dystonia and parkinsonism. Pretreatment with the 5-HT antagonists cyproheptadine and mianserin increased amphetamine-induced locomotor activity, reactivity and repetitive movements and decreased haloperidol-induced dystonia and parkinsonism. Conversely the 5-HT uptake inhibitors paroxetine and CGP 6085 A decreased amphetamine-induced repetitive movements and aggravated haloperidol-induced dystonia and parkinsonism. The 5-HT uptake inhibitors produced oral hyperkinesia resembling human tardive dyskinesia, which was intensified by amphetamine and blocked by haloperidol. These findings support the suggestion that 5-HT inhibits dopamine functions and may imply that 5-HT antagonists could have a beneficial effect against acute extrapyramidal side-effects of neuroleptic treatment. 5-HT uptake inhibitors in the monkey may serve as a model for tardive dyskinesia.

Effects of apomorphine and haloperidol on "spontaneous" stereotyped licking behaviour in the Cebus monkey

Three recently arrived drug naive Cebus apella monkeys with "spontaneous" stereotyped oral movements were treated with apomorphine and haloperidol using a wide dose range. Low doses of apomorphine (0.05-0.1 mg/kg) suppressed the oral stereotypies without affecting normal behaviour such as grooming and scratching. Higher doses of apomorphine (0.25-1.0 mg/kg) and haloperidol (0.01-0.1 mg/kg) also decreased or abolished the oral stereotypies, but induced generalized stereotypies (apomorphine) or dystonia/parkinsonism (haloperidol), suppressing normal behaviour. The findings indicate that dopamine is involved in these presumably stress-induced (not drug-induced) stereotypies.

Fluperlapine in tardive dyskinesia and parkinsonism

Fluperlapine, a new clozapine-like neuroleptic drug with weak affinity for dopamine receptors, was evaluated in a blind, placebo controlled trial in 11 patients with stable hyperkinesia (ten with tardive dyskinesia (TD) and one with spontaneous dyskinesia). Drug effects during active treatment (200-600 mg/day) and during pre- and post-treatment placebo periods were determined by scoring randomly sequenced videotapes of TD and parkinsonian symptoms recorded weekly during standardized examinations. TD score was unchanged, while parkinsonism slightly decreased (P less than 0.05) and eye-blinking rates increased (P less than 0.05). Psychiatric symptoms showed no significant changes, although positive psychotic symptoms diminished in four patients. Side effects included dizziness, sedation and constipation. The effects in movement disorders found in this study may imply that fluperlapine is less liable than traditional neuroleptics to induce acute extrapyramidal side effects and tardive dyskinesia and is particularly beneficial in the treatment of patients vulnerable to neurological side-effects.

Effect of gamma-vinyl GABA in tardive dyskinesia

gamma-Vinyl GABA (gamma-aminobutyric acid), a drug that increases brain GABA via GABA transaminase inhibition, was evaluated in a blind, placebo-controlled trial in 10 patients with stable tardive dyskinesia. Drug effects during active treatment (2 to 6 g/day) and during pre- and posttreatment placebo periods were determined by scoring randomly sequenced videotapes of tardive dyskinesia and parkinsonian symptoms recorded weekly during standardized examinations. Tardive dyskinesia was significantly reduced, and correlated to increased parkinsonism. Eye blinking rates decreased, but psychiatric symptoms were unchanged during treatment.

Chronic psychosis in epilepsy. A clinical investigation of 29 patients

A clinical study comprising psychiatric, psychological and neurological examination of 29 patients suffering from long-term psychosis and severe epilepsy was performed. Only five patients fulfilled the diagnostic criteria of schizophrenia. They differed from the rest of the patients by being less organic and having infrequent laterality to the left of their epileptogenic focus. They were regarded as genuine schizophrenics, while the pathogenesis of the remaining sample was considered multifactorial, including both organic and psycho-social causes.

The effect of tetrahydroisoxazolopyridinol (THIP) in tardive dyskinesia: a new gamma-aminobutyric acid agonist

gamma-Aminobutyric acid (GABA) agonists have been proposed for the treatment of tardive dyskinesia, but their therapeutic potential has been limited by side effects and toxicity. To elucidate further the role of GABA in neuroleptic-induced dyskinesias, we evaluated tetrahydroisoxazolopyridinol (THIP), a new, less toxic GABA analog and GABA receptor agonist, in both a dose-finding (single-dose) pilot study with five patients and a longer (four-week) placebo-controlled study with 13 patients. The patients were videotaped during a standardized examination; tardive dyskinesia, parkinsonian symptoms, and eye-blinking rates were rated blindly and randomly. The maximal short-term dose of THIP was 10 to 25 mg, whereas in the longer-term study the highest daily dose ranged from 20 to 120 mg. Tardive dyskinesia was unchanged during THIP treatment, but preexisting parkinsonism increased significantly and eye-blinking rates decreased. Psychiatric symptoms showed no significant changes, although tension and depression lessened. Side effects included sedation, confusion, dizziness, vomiting, and myoclonic jerks. Although THIP is not an effective new treatment for tardive dyskinesia, more specific GABA agonists should be evaluated in future studies of this syndrome.

Epilepsy and psychosis

In an attempt to survey the evidence of causal relationship between epilepsy and chronic psychosis the literature has been searched with respect to frequency of psychoses, psychopathological classifications and correlations between biological and behavioural variables. It is concluded that a unitary theory of aetiology in epileptic psychosis can not be maintained. The psychotic pictures seldom fulfill the Bleulerian concept of schizophrenia, and consequently the term schizophrenia-like should be avoided. With respect to future investigations a prospective research method is advocated.

High-dose destyrosine-gamma-endorphin in tardive dyskinesia

Destyrosine-gamma-endorphin (DTGE) has purported neuroleptic properties, although the findings have been conflicting. Four chronic psychotic inpatients with neuroleptic-induced dyskinesias were treated with single injections of placebo and DTGE in high doses (20-120 mg). No consistent differences were found in tardive dyskinesia, parkinsonism, eye-blinking rates, or mental status. Laboratory tests were unchanged. It is concluded that acute DTGE treatment has no beneficial effect in drug-induced dyskinesia.

Effect of des-tyrosine-gamma-endorphin in tardive dyskinesia

The endorphin neuropeptides may have neuroleptic-like effects on dopamine function and may be antischizophrenic. Ten chronic psychotic patients with neuroleptic-induced tardive dyskinesia and parkinsonism received placebo and des-tyrosine-gamma-endorphin (DT gamma E). Drug effects on movement disorders and eye-blinking rates were assessed by blind evaluations of randomly sequenced videotapes made during standardized examinations before and 30, 60, and 120 minutes after each injection and at 24 hours postinjection on days of consecutive treatment. Changes in schizophrenic symptoms were evaluated openly with the schizophrenia subscale of the Comprehensive Psychiatric Rating Scale. There were no significant effects of DT gamma E on any parameter and no side effects. This suggests that DT gamma E, within the tested dose range, does not influence the pathophysiology of neuroleptic-induced dyskinesias or chronic schizophrenia or have neuroleptic properties. However, DT gamma E is well tolerated and should be tested with higher doses during prolonged treatment.

Vasopressin in anergic schizophrenia. A cross-over study with lysine-8-vasopressin and placebo

Sixteen out of 19 patients suffering from chronic anergic schizophrenia completed a placebo-controlled cross-over study with lysine-8-vasopressin (LVP), following a schedule of 1 week of placebo, 3 weeks of LVP, starting with 22.5 IU/day, gradually increased to 67.5 IU/day, and finally 4 weeks of placebo. The psychic state was evaluated with the Brief Psychiatric Rate Scale (BPRS), during weekly live interviews, and following videotaped BPRS interviews at the beginning and end of the LVP period, and at the end of the final placebo period. Symptoms of parkinsonism and tardive dyskinesia were also videotaped during a standardized examination at the same intervals. The videotapes were subsequently randomized and evaluated blindly. The results of liver interviews showed a significant (P less than 0.05) decrease in the BPRS anergic factor after 2 and 3 weeks of LVP treatment, but there were no changes in any single item, other BPRS factors, or the BPRS total score. The results of the videotape evaluations showed that the BPRS thinking disorder factor was significantly (P less than 0.05) decreased after 3 weeks of LVP, whereas the BPRS score was unchanged. No consistent changes in parkinsonism or tardive dyskinesia were found. Although side effects were few, six patients became agitated or aggressive during the LVP treatment. The beneficial effect on thought disorder and anergia, but the absence of global effects on the schizophrenic syndrome, illustrates the need for further research with other vasopressin analogues. The advantages and disadvantages of live and videotaped psychiatric interviews are also discussed.

Amoxapine versus amitriptyline in endogenous depression. A double-blind study

A new antidepressant, amoxapine, which is a dibenzoxazepine deprivative, was compared with amitriptyline in a randomised double-blind trial. Forty-eight patients were included and 41 completed a 4-week treatment. Most of the patients were maintained on 150 mg daily. Assessments were made by the Hamilton Psychiatric Rating Scale for Depression (HAM-D), Nurses' Observation Scale for Inpatient Evaluation (NOSIE), Clinical Global Impression (CGI) scale and Patient's Self-Evaluation. The total HAM-D score was considerably reduced in the majority of the patients. Amitriptyline was the most effective with regard to symptoms included in the factor Sleep Disturbances and-secondary maybe-towards some items included in the factor Somatization. For the remaining items,including the items of the factors Anxiety/Depression and Apathy, the last score was lower in the amoxapine group than in those treated with amitriptyline. Among the unipolar cases the amoxapine treated patients were more satisfied with regard to efficacy (P = 6.3%). The frequency of side effects such as tremor and dizziness was considerably lower in the amoxapine group. In total, the side effects lasted longer in the amitriptyline group. We conclude that amoxapine seems to be an effective antidepressant with a low frequency of side effects.

Increase in weight after treatment with depot neuroleptics

A trial has been performed investigating changes in weight in 99 female patients who have been treated with clopenthixol decanoate or perpehnazine enanthate after prior treatment with different oral neuroleptics. We found a significantly higher mean weight after the oral treatment period and a slight, but not statistically significant, further weight increase after the following depot period. In addition the rate of increase in weight was significantly lower during the depot treatment period. These increases might be due to achievement of a steady-state in weight during the first treatment period with oral intake. We found no difference between clopenthixol decanoate and perphenazine enanthate as regards change in weight or rate of change in weight.

Baclofen (Lioresal) in the treatment ofneuroleptic-induced tardive dyskinesia

A double-blind cross-over trial of the effects of baclofen and placebo was carried out in 20 female patients suffering from neuroleptic-induced tardive dyskinesia. After 14 days of treatment 15 patients showed improvement of baclofen, whereas none showed improvement on placebo; baclofen was thus significantly more effective than placebo. Baclofen is a GABA-like drug which passes through the blood-brain barrier and which reduces the neuroleptic-induced increase of dopamine turn-over. In tardive dyskinesia is found dopaminergic hypersensitivity, and baclofen is supposed to exert its action by inhibiting the dopamine activity. Side effects, although temporary, were observed in the form of sedation, muscular hypotonia, dizziness, vomiting, and muscular rigidity. One patient developed a depression. Baclofen or other gabergic drugs used in the treatment of dyskinesias do not increase the dopaminergic hypersensitivity, which is part of the pathogenesis of these conditions; gabergic therapy must therefore be preferred to treatment with dopamine receptor blocking drugs.