Long-term Preventive Effects Research Articles

Long‐term Efficacy of Specific Immunotherapy on House Dust Mite–Induced Allergic Rhinitis in China

Although the effect of specific immunotherapy (SIT) on allergic rhinitis (AR) has been well documented in developed countries, its long-term efficacy in patients in developing countries (such as China) is poorly understood. This study investigated the long-term therapeutic and preventive effects of SIT on house dust mite (HDM)-induced AR in patients from China. Historical cohort study. University hospital. One hundred forty-six AR patients with/without asthma allergic to HDM were investigated for 5 years after initiation of a 3-year course of subcutaneous SIT (SIT group, n = 106) or no SIT (control group, n = 40). The clinical responses of all patients were evaluated at baseline, the stop point of SIT (third year), and 2 years after SIT termination (fifth year), by clinical index including symptom and rescue medication scores (SMS), visual analog scale (VAS), total immunoglobulin E (tIgE), and specific IgE (sIgE). Asthma was assessed by clinical evaluation. The decrease of SMS and VAS from baseline was significantly improved in the SIT group compared with controls at both the third and fifth year. For patients without asthma at baseline, the odds ratio for no asthma was 3.57 (95% confidence interval, 1.05-12.91; P < .05) in favor of SIT. The serum sIgE/tIgE ratio was significantly increased after SIT treatment in the SIT group, but it was not related to SIT efficacy. SIT has a long-term effect of improving clinical symptoms and reducing the risk of development of asthma in Chinese AR patients.

A Markov model of the cost-effectiveness of pharmacist care for diabetes in prevention of cardiovascular diseases: evidence from Kaiser Permanente Northern California.

It has been demonstrated in previous studies that pharmacist management of patients with type 2 diabetes mellitus (T2DM) in the outpatient setting not only improves diabetes-related clinical outcomes such as hemoglobin A1c but also blood pressure (BP), total cholesterol (TC), and quality of life. Improved control of BP and TC has been shown to reduce the risks of cardiovascular disease (CVD), which has placed a heavy economic burden on the health care system. However, no study has evaluated the cost-effectiveness of pharmacist intervention programs with respect to the long-term preventive effects on CVD outcomes among T2DM patients. To (a) quantify the long-term preventive effects of pharmacist intervention on CVD outcomes among T2DM patients using evidence from a matched cohort study in the outpatient primary care setting and (b) assess the relative cost-effectiveness of adding a clinical pharmacist to the primary care team for the management of patients with T2DM based on improvement in CVD risks with the aid of an economic model. Clinical data between the periods of June 2007 to February 2010 were collected from electronic medical records at 2 separate clinics at Kaiser Permanente (KP) Northern California, 1 with primary care physicians only (control group) and the other with the addition of a pharmacist (enhanced care group). Patients in the enhanced care group were matched 1:1 with patients in the control group according to baseline characteristics that included age, gender, A1c, and Charlson comorbidity score. The estimated 10-year CVD risk for both groups was calculated by the United Kingdom Prospective Diabetes Study (UKPDS) Risk Engine (version 2) based on age, sex, race, smoking status, atrial fibrillation, duration of diabetes, levels of A1c, systolic BP (SBP) and TC, and high-density lipoprotein cholesterol (HDL-C) observed at 12 months. There was no statistical difference in the baseline clinical inputs to the Risk Engine (A1c [P=0.115], SBP [P=0.184], TC [P=0.055], and HDL-C [P=0.475]) between the 2 groups. A Markov model was developed to simulate the estimated CVD outcomes over 10 years and to estimate cost-effectiveness. The final outcomes examined included incremental cost and effectiveness measured by life years and per quality-adjusted life year gained. Both deterministic sensitivity analysis (SA) and probabilistic SA were conducted to examine the robustness of the results. The estimated risks for coronary heart disease (CHD) and stroke (both nonfatal and fatal) at the end of the follow-up were consistently lower in the enhanced care group compared with the control group, even though baseline risks in both groups were similar. The absolute risk reduction (ARR) between the enhanced care and control groups increased over time. For example, the ARR for nonfatal CHD risk in year 1 was 0.5% (1.2% vs. 0.7%), whereas the ARR increased to 5.5% in year 10 (14.8% vs. 9.3%). Similarly, the ARR between the enhanced care and the control groups was calculated as 0.3% for fatal CHD in year 1 and increased to 4.6% in year 10. Results from the Markov model suggest that the enhanced care group was shown to be a dominant strategy (less expensive and more effective) compared with the control group in the 10-year evaluation period in the base-case (average or mean results) scenario. Sensitivity analysis that took into account the uncertainty in all important variables, such as wage of pharmacists, utility weight (the degree of preference individuals have for a particular health state or condition), response rate to pharmacists' care, and uncertainty associated with the estimated 10 years of CVD risk, revealed that the relative value of enhanced care was robust to most of the variations in these parameters. Notably, the level of cost-effectiveness measured by net monetary value depends on the time horizon adopted by the payers and the magnitude of CVD risk reduction. The enhanced care group has a higher chance of being considered as a cost-effective strategy when a longer time horizon such as a minimum of 4 to 5 years is adopted. Adding pharmacists to the health care management team for diabetic patients improves the long-term CVD risks. The longer-term CVD risk reductions were shown to be more dramatic than the short-term reduction. A longer time horizon adopted by health plans in managing T2DM patients has a higher probability of making the intervention cost-effective.

Long-term Caries Preventive Effects of a School-Based Fluoride Mouth Rinse Program in Adulthood

The purpose of this study was to evaluate the long-term caries preventive effects of school-based fluoride mouth rinse (FMR) program in adults aged 20 years and older. 637 mothers aged from 20 to 39 years were surveyed. Clinical examinations were carried out for subjects to obtain data on dental caries prevalence when they visited local health centers to take their children for medical and dental check-ups at 1.5- or 3-years old. We also obtained information regarding the FMR program: the duration that the subjects participated between nursery school and junior high school. When analyzing data, subjects were divided into 4 groups: FMR from nursery to junior high school group (N-JH group, n=22), FMR limited to the elementary school group (El group, n=62), FMR no-experience group (n=545), and other subjects whose FMR experience is not clear (n=8). For evaluation of the FMR program effect, multiple regression analysis was used. As independent variable, the FMR program patterns were converted into dummy data, and mean DMFT was used as dependent variable. The results of multiple regression analysis between mean DMFT and FMR program patterns showed that the N-JH group and El group were negatively associated with the mean DMFT (ß=-0.20, p<0.001 for N-JH group and ß=-0.11, p=0.003 for El group).The positive caries preventive effects of school-based FMR program from nursery school to junior high school can continue in adults aged 20 years and older.

Long-Term Effects of Preventive Cognitive Therapy in Recurrent Depression

Major depressive disorder (MDD) was projected to rank second on a list of 15 major diseases in terms of burden in 2030. A crucial part of the treatment of depression is the prevention of relapse/recurrence in high-risk groups, ie, recurrently depressed patients. The long-term preventive effects of group cognitive therapy (CT) in preventing relapse/recurrence in recurrent depression are not known. This article reports on the long-term (5.5-year) outcome of a randomized controlled trial to prevent relapse/recurrence in patients with recurrent depression. We specifically evaluated the long-term effects of CT in relation to the number of previous episodes experienced. From February through September 2000, patients with recurrent depression (DSM-IV-diagnosed) who were in remission (N = 172) were recruited from primary and specialty care facilities. They were randomly assigned to treatment as usual (TAU) versus TAU augmented with brief group CT. The primary outcome measure was time to relapse/recurrence, which was assessed over 5.5 years. Over 5.5 years, augmenting TAU with CT resulted in a significant protective effect (P = .003), which intensified with the number of previous depressive episodes experienced. For patients with 4 or more previous episodes (52% of the sample), CT significantly reduced cumulative relapse/recurrence from 95% to 75% (medium effect size). Our findings indicate that brief CT, started after remission from a depressive episode on diverse types of treatment in patients with multiple prior episodes, has long-term preventive effects for at least 5.5 years. Implementation of brief relapse prevention CT should be considered in the continued care of patients with recurrent depression. ccmo-online.nl Identifier: NTR454.

Pregnancy rates among juvenile justice girls in two randomized controlled trials of multidimensional treatment foster care.

Preventing adolescent pregnancy is a national research priority that has had limited success. In the present study, the authors examined whether Multidimensional Treatment Foster Care (MTFC) relative to intervention services as usual (group care [GC]) decreased pregnancy rates among juvenile justice girls mandated to out-of-home care. Girls (13-17 years of age) with histories of criminal referrals (Mdn = 10) were randomly assigned to MTFC (n = 81) or GC (n = 85) as part of 2 randomized controlled trials. Pregnancy histories were assessed from baseline through 24 months. Fewer postbaseline pregnancies were reported for MTFC girls (26.9%) than for GC girls (46.9%)--an effect that remained significant after controlling for baseline criminal referrals, pregnancy history, and sexual activity. MTFC has previously been shown to decrease arrest and lock-up rates. The present findings support the long-term preventive effects of MTFC on adolescent girls' pregnancy rates. Findings are consistent with the notion that programs that target delinquency by impacting general risk behavior pathways and contexts may more successfully prevent teen pregnancy than those that directly target sexual behaviors.

Effect of Early Statin Treatment at Standard Doses on Long-Term Clinical Outcomes in Patients With Acute Myocardial Infarction (The Heart Institute of Japan, Department of Cardiology Statin Evaluation Program)

Long-term preventive effects of standard statin therapy in patients with acute myocardial infarction (AMI) against a secondary cardiac event remain unclear. The aims of this study were to evaluate and clarify characteristics of patients with AMI in whom standard statin therapy has beneficial effects against a secondary event in a real-world setting. Between 1999 and 2004, 4,075 patients with AMI were registered and followed prospectively, of whom 1,404 (matched by propensity scores) were analyzed. Statin use was defined as prescription on discharge from the hospital, and the control group was not prescribed statins at discharge. The primary end point was total mortality rate. Final follow-up was performed in June 2006 (median 4.1 years), and follow-up rate was 97.2%. During follow-up, 139 patients died, including 87 (12.4%) from the control group and 52 (7.4%) from the statin group. The hazard ratio for statin therapy was 0.64 (95% confidence interval 0.45 to 0.90, p = 0.011) throughout the study. Early statin therapy was strongly correlated with a lower risk of cardiovascular death, less recurrence of AMI, and less heart failure. Statin therapy was particularly beneficial for men, patients > or =60 years of age, and patients with a high low-density lipoprotein cholesterol level > or =155 mg/dl. In conclusion, these findings suggest that initiating standard rather than intensive statin therapy immediately after AMI decreases long-term mortality and subsequent cardiac events.

Therapeutic effects of roxithromycin in interleukin-10-deficient colitis

A limited number of therapeutic strategies are currently available to treat patients with inflammatory bowel disease (IBD). Interleukin-10 (IL-10)-deficient mice, well characterized as an experimental model of IBD, develop severe chronic colitis because of aberrant Th1 responses. Roxithromycin (RXM), a macrolide antibiotic, has received attention because it offers not only antibacterial but also immunosuppressive effects. We examined the immunosuppressive effect of RXM on the development of IBD. To test the efficacy of short-term administration of RXM, elder IL-10-deficient mice (16-20 weeks old) with established colitis were orally treated for 10 days with RXM (20 mg/kg per day). To test the long-term preventive effects of RXM, for 20 weeks young adult IL-10-deficient mice (4-5 weeks old) also were administered RXM orally (20 mg/kg per day). The short-term treatment-oriented administration of RXM reduced the degree of inflammatory change and lowered serum amyloid A in IL-10-deficient mice with severe colitis. Mononuclear cells from the lamina propria of RXM-treated large intestines showed lower production of IFN-gamma than did those from diseased mice that were untreated. Long-term prevention-oriented administration of RXM suppressed the development of severe colitis and decreased production of IFN-gamma and IL-12. In addition to its expected immunosuppressive effect, RXM treatment also decreased the level of Bacteroides vulgatus, a Gram-negative anaerobe. The anti-inflammatory changes observed in IL-10-deficient mice resulted from the efficacy of RXM as an immunosuppressant as well as from its efficacy as an antibiotic. According to our findings, RXM would seem to have significant potential as a preventive and/or therapeutic agent for IBD.

Preventive Effects of Treatment of Disruptive Behavior Disorder in Middle Childhood on Substance Use and Delinquent Behavior

Disruptive behavior disorder (DBD) is a well-known risk factor for substance abuse and delinquent behavior in adolescence. Therefore, the long-term preventive effects of treatment of DBD in middle childhood on beginning substance use and delinquency in early adolescence were investigated. Children with DBD (8-13 years old) had been randomly assigned to manualized behavior therapy (Utrecht Coping Power Program; UCPP) or to care as usual (CU) in the Netherlands. Five years (2003-2005) after the start of treatment (1996-1999), substance use and delinquency were monitored in 61 of the initial 77 adolescents and compared with a matched healthy control group by means of self-report questionnaires. One-factor analyses of variance and Pearson's chi2 analyses were performed. Differences in substance use were revealed in favor of the UCPP, with more adolescents in the CU group smoking cigarettes in the last month (UCPP 17%, CU 42%; chi2 = 4.7; p < .03) and more adolescents in the CU group having ever used marijuana (UCPP 13%, CU 35%; chi2 = 4.0; p < .045). Moreover, in this respect, the UCPP fit in the range of the matched healthy control group. Both treatment groups were comparable to the matched healthy control group in delinquent behavior. Manualized behavior therapy for DBD in middle childhood seems to be more powerful than CU in reducing substance use in early adolescence. Both treatment conditions show a beneficial long-term preventive effect on delinquency.

Prevention of depression in subclinically depressed adults: Follow-up effects on the ‘Coping with Depression’ course

Background People with subclinical depressive symptoms are at increased risk of depressive disorder, little is known on the prevention of depressive disorder in this population. This study evaluates the long-term preventive effects of an effective depression treatment, the Coping with Depression (CWD) course. This paper describes the effect of the CWD course on the incidence of depressive episodes and depressive symptoms, and explores whether the initial level of symptoms and gender has differential intervention effects. Methods Participants ( N = 104) were adults with subclinical depressive symptoms, who were randomly assigned to either a preventive group course condition, the ‘Coping with Depression’ course, or to an assessment-and-advice-only control group condition. Follow-up results were measured 6 and 12 months after completion of the course. Results The CWD course showed to be effective in preventing depressive symptomatology but there was no evidence that the course prevented depressive disorder. 25% of the control group and 27.3% of the course group developed a depressive disorder within a year. Initial depressive symptomatology moderated the outcomes: only participants with low initial symptomatology appeared to benefit in the long term from course participation. Conclusions The CWD course is effective as a treatment for subclinical depression. Preventive effects are restricted to participants with initially low depression levels. Therefore, this subgroup should be targeted in future depression-prevention practices and in future prevention studies.

Two to three years of hormone replacement treatment in healthy women have long-term preventive effects on bone mass and osteoporotic fractures: the PERF study

Hormone replacement therapy (HRT) is often prescribed for a few years to suppress menopausal symptoms. Although its long-term use of HRT for the primary prevention of osteoporosis is not currently recommended, the long-term skeletal benefits of the limited therapy are of great interest. To determine whether administration of HRT for 2–3 years in the early postmenopausal years provides long-term benefits, such as prevention of bone loss and osteoporotic fractures, we studied a group of 347 healthy postmenopausal women with normal bone mass who had earlier completed one of four placebo-controlled HRT trials and who were reexamined 5, 11, or 15 years after stopping HRT. Of these women, 263 received either HRT or placebo for 2–3 years with no further bone-sparing treatment until follow-up, and the remaining 84 women reported either prolonged or current use of HRT at reexamination. Bone mineral density (BMD) at the spine (L1–L4) and bone mineral content (BMC) in the forearm were measured at baseline, the end of the trials, and follow-up. At follow-up, we assessed the radiological presence of vertebral fracture and collected information on the new incidence of nonvertebral fractures. Compared with that of the placebo-treated women, the BMD and BMC of HRT-treated women continued to show significantly higher values (>5%) even many years after stopping HRT. After stopping treatment, the rate of bone loss returned to normal postmenopausal rates. The preservation of bone mass in the HRT group was accompanied by a significantly reduced risk of all osteoporotic fractures as compared with the placebo group [OR = 0.48 (95% CI, 0.26–0.88)]. ‘Fast losers’ on placebo had more than a 4-fold higher risk of fractures than had the women on limited HRT with a normal rate of bone loss after withdrawal. In conclusion, limited HRT administered in the early postmenopausal years offers long-lasting benefits for the prevention of postmenopausal bone loss and osteoporotic fracture.

Short-term effect of partially hydrolyzed formula on the prevention of development of atopic dermatitis in infants at high risk.

This short-term, prospective study was aimed to assess the effects of partially hydrolyzed formula (PHF) on the prevention of the development of atopic dermatitis in infants at high risk. The infants of parents with allergy symptoms and serum total IgE over 200 kU/L were divided into 3 groups by their feeding patterns: PHF group (n=15), standard formula (SF) group (n=32), and breast milk (BM) group (n=22). No allergenic food was given during the study period of 6 months, and breastfeeding mothers avoided egg ingestion. Their atopic symptoms were monitored every 2 months. The cumulative incidence and prevalence of atopic dermatitis at the age of 6 months were significantly less in the PHF group than in the SF group (47% vs. 78%, p<0.05; 20% vs. 59%, p<0.05). Those rates of the PHF group were also less than those of the BM group, but they were not statistically significant. There was no difference in the onset age and disease severity. These results suggest that early feeding of PHF to infants at high risk has a short-term preventive effect on the development of atopic dermatitis during the first 6 months of life. Long-term preventive effects should be evaluated.

Long-term and preventive effects of sublingual allergen-specific immunotherapy: a retrospective, multicentric study.

There is now an increasing body of evidence to support the practice of allergen-specific sublingual-swallow immunotherapy (SLIT) in the treatment of IgE-mediated respiratory allergies. Recent studies on traditional injection therapy have pointed out that this form of treatment is not only capable to decrease actual allergic symptoms, but may also have long-term clinical and preventive effects and may influence atopy natural history. In the year 2000, our group published a retrospective, multicenter study showing the efficacy and safety of SLIT in a survey of 302 patients. We now carried out a second study on the same patients, with the aim of investigating long-term and preventive effects of SLIT. Beside the well-known safety and efficacy of this treatment (80.8% of patients reported clinical benefits), SLIT proved also to elicit long term clinical effects: over a mean follow-up of 11.6 months after the end of treatment, 80.8% of patients still maintained the previously achieved benefits. During the follow-up period, only 1% of non-asthma patients reported an onset of respiratory symptoms, and only 9.6% of patients undergoing new skin tests showed new sensitizations. All the clinical benefits were strongly linked to the length of treatment: patients with long-lasting benefits were treated for a mean length of 29.1 months, while patients showing a return to pre-SLIT condition were treated for a mean 13.3 months. SLIT can obtain long-term and preventive effects so far attributed to injection immunotherapy.

Effects of Angiotensin-Converting Enzyme Inhibitor, Angiotensin II Receptor Antagonist and Calcium Antagonist on Urinary Podocytes in Patients with IgA Nephropathy

The urinary podocyte is postulated to be a marker for estimation of the severity of active glomerular injury and a predictor of disease progression in children with glomerulonephritis. Non-dihydropyridine calcium antagonist, including verapamil, reduce proteinuria to an extent similar to that of the angiotensin-converting enzyme inhibitor (ACEI), including trandolapril, but to a greater extent than other antihypertensives. Angiotensin (Ang) II receptor antagonists, including candesartan cilexetil, show potent and long-term preventive effects against the progression of renal injury. The aim of the present study is to assess whether verapamil, trandolapril and candesartan cilexetil affect proteinuria and urinary podocytes in patients with IgA nephropathy. Thirty-two normotensive patients aged 18-54 years with biopsy-proven IgA nephropathy, nonnephrotic proteinuria (1-3 g/day), and normal renal function (creatinine clearance >80 ml/min) were studied. Twenty patients with diffuse mesangial proliferative glomerulonephritis (non-IgA PGN) and 20 healthy controls were also included in this study. The number of urinary podocytes in patients with advanced IgA nephropathy (n = 16) was significantly higher than that in patients with the disease in the mild stage (n = 16) (p < 0.01) or in patients with non-IgA PGN (p < 0.01). Urinary podocytes were not detected in healthy controls. The 32 patients with IgA nephropathy were randomly divided into four treatment groups: those treated with verapamil (120 mg/day, n = 8); those treated with trandolapril (2 mg/day, n = 8); those treated with candesartan cilexetil (8 mg/day, n = 8), and those given a placebo (n = 8). Treatment continued for 3 months. Antiproteinuric response in the trandolapril group was similar to that in the candesartan cilexetil group (-38 vs. -40%). The action of trandolapril or candesartan cilexetil was greater than that of verapamil (p < 0.01). Reduction in the number of urinary podocytes from baseline was significantly greater in patients treated with trandolapril or candesartan cilexetil than in patients treated with verapamil (p < 0.01). However, there was no difference between patients treated with trandolapril and those treated with candesartan cilexetil. Proteinuria and urinary podocytes were unaffected in the placebo group. These data suggest that urinary podocytes may be a marker of disease activity in adult patients with IgA nephropathy and that trandolapril and candesartan cilexetil are more effective than verapamil in reducing the number of podocytes.

Effect of candesartan cilexetil (TCV-116) in rats with chronic renal failure

Inhibition of the renin-angiotensin system by both angiotensin II type 1 receptor antagonists (AT1As) and angiotensin I-converting enzyme inhibitors (ACEIs) shows renoprotective effects in rats with chronic renal failure when treatment is started in the early phase of renal injury. In this study, we examined the renal protective effects of candesartan cilexetil (TCV-116), an AT1A, and enalapril, an ACEI, in the progressive phase of renal injury in 5/6 nephrectomized rats. Candesartan cilexetil (1 mg/kg/day) and enalapril (10 mg/kg/day) were orally administered once a day for 4 weeks (the short-term experiment) or 16 weeks (the long-term experiment) to 5/6 nephrectomized rats beginning 15 weeks after the nephrectomy, that is, after they had already showed marked proteinuria. In vehicle-treated rats, proteinuria, glomerulosclerosis, and interstitial fibrosis developed. Moreover, enhanced expression of transforming growth factor-beta1 (TGF-beta1) in the injured glomeruli was observed. These adverse changes progressed with time, and in the short-term experiment, both drugs inhibited them. In the long-term experiment, the progressive proteinuria and the elevation of blood pressure were similarly attenuated by both drugs. However, candesartan cilexetil significantly inhibited the progression of glomerulosclerosis, the expression of TGF-beta1, and interstitial fibrosis, whereas enalapril did not. These results indicate that candesartan cilexetil shows potent and long-term preventive effects against the progression of previously developed renal injury.

Étude de l'effet antalgique et fonctionnel du port d'une orthèse lombaire souple dans la lombalgie aiguë

Introduction To study the effect of a lumbar belt on pain intensity and daily activities in patients with low back pain. Method Multi-center, randomised study comparing a group treated with a lumbar belt and a control group. Thirty-six subjects, men and women, with a mean age of 38.35 0.2 years suffering from low back pain and examined for the first time. Pain intensity, the clinical examination and the functional performances are evaluated after 8 and 21 days of treatment. Results The results show a good effect of the lumbar belt on pain intensity at 8 and 21 days, a partial effect on clinical parameters and functional performances. Conclusion These results, in spite of a small sample of population, contribute to determine the efficacy of lumbar belt in the treatment of low back pain, but also show the need for further studies, particularly on their long-term preventive effects in the workplace.

Short-term treatment with prostaglandin E 1 analogue has long-term preventive effects on intimal thickening in balloon-injured rat carotid arteries

We examined effects of a prostaglandin E 1 analogue alprostadil on intimal thickening and arterial remodeling in balloon-injured rat carotid arteries. Right common carotid arteries were balloon-injured, and their left counterparts were sham-operated (uninjured). Rats were given alprostadil (0.3 μg/kg/min, continuous subcutaneous (s.c.) infusion) or vehicle for 1 week after the injury and sacrificed at 4 weeks or 8 weeks. Segments of common carotid arteries corresponding to balloon-injured and uninjured sites were excised and subjected to elastica van Gieson staining. Cross-sectional areas were measured by computed planimetry. Alprostadil prevented intimal thickening at both 4 and 8 weeks. In addition, alprostadil prevented the increase in intimal area/area surrounded by external elastic lamina at both 4 and 8 weeks. Alprostadil had no effects on body weight, heart rate, or systolic blood pressure. Our study demonstrated that alprostadil administered only for the initial 1 week had long-term (up to 8 weeks) preventive effects on intimal thickening. Alprostadil may be useful to prevent restenosis after balloon angioplasty.

Home Care Research: What Does It Tell Us?

This article assesses the applied relevance of research on home care, reviewing the literature on predictors of use of home care services, the experience of receiving home care, and efficacy studies. Research to date informs us rather conclusively that functioning is a major predictor of use throughout the industrialized world, but does not inform us of the structural factors impacting on home care. Studies on the experience of home care, to date, have focused on program implementation issues, rather than more macro policy issues. Finally, efficacy studies by and large have not concluded that home care is less costly or necessarily better for the quality of life of seniors when compared with institutional care. This has led to questions about the raison d'être of home care. We do not have longitudinal research assessing the long-term preventive effects of home care.

Long-term effect of xylitol chewing gum on dental caries.

About 85% (n = 269) of the subjects who participated in the Ylivieska follow-up studies on the effect of xylitol chewing gum on dental caries during 1982-84 or 1982-85 were re-examined in 1987 for the analysis of possible long-term preventive effects. Further caries reduction was found 2 or 3 yr after the discontinuation of the use of xylitol. The effect was especially marked in girls; the reduction in caries increment in the post-use years was 60% for the 2-yr users, suggesting that more pronounced caries reduction was associated with the most regular use of xylitol. In teeth erupting during the first year of the use of xylitol gum the long-term preventive effect was greater than in other teeth. Several explanations are suggested: lasting effect of the microbiological changes in the mouth, bacterial colonization on newly erupted teeth by organisms other than S. mutans, and/or thorough maturation of the teeth under favorable physico-chemical circumstances. The results suggest that the value of xylitol in caries prevention depends on the timing of the treatment in relation to the development of the dentition.